Workers at CCAS attach solar panel to FUSE satellite.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), workers check the installation of a solar panel on NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket.

Workers at CCAS attach solar panel to FUSE satellite.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), workers attach a solar panel to NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket.

KSC-99pp0667

NASA Image and Video Library

1999-06-12

Workers at Hangar AE, Cape Canaveral Air Station (CCAS), check NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite after moving it from the scaffolding behind it. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. The satellite is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

Building for the Future: China’s Progress in Space Technology During the Tenth 5-Year Plan and the U.S. Response

DTIC Science & Technology

2008-03-01

solar telescope to study solar physics. — Develop technologies for a three-satellite constellation called Kua Fu to study solar activity that will...consist of one satellite to monitor solar activity and two others to study the aurora. • International cooperation. Participate in the Sino...Russian Mars environment exploration plan, the World Space Observatory Ultraviolet Project,50 and the Sino-French Small Satellite Solar Flare Exploration

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

Workers at Hangar AE, Cape Canaveral Air Station (CCAS), adjust the canister segments they are installing around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is being prepared for its transfer to Launch Pad 17A, CCAS, and its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

Workers at Hangar AE, Cape Canaveral Air Station (CCAS), fit the second row of canister segments around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is being prepared for its transfer to Launch Pad 17A, CCAS, and its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), workers on scaffolding pull down a weather-proofing cover over the canister surrounding NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite will next be moved to Launch Pad 17A, CCAS, for its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

The International Ultraviolet Explorer: Case study in spacecraft design

NASA Technical Reports Server (NTRS)

Freeman, H. R.; Longanecker, G. W.

1979-01-01

The International Ultraviolet Explorer (IUE) is a geosynchronous scientific satellite that was conceived as an international space observatory capable of measuring UV spectra of faint celestial bodies. Simple operational procedures allow the astronomers to joystick the spaceborne telescope about the sky, using familiar ground-based observatory techniques. The present paper deals with the IUE project objectives, the technical problems, constraints, trade-offs, and the problem solving techniques used in the IUE program.

KSC-99pp0742

NASA Image and Video Library

1999-06-24

Clouds of smoke and steam billow around the Boeing Delta II rocket as it roars into the sky after liftoff at 11:44 a.m. EDT from Launch Pad 17A, Cape Canaveral Air Station. The rocket is carrying NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99padig001

NASA Image and Video Library

1999-06-24

The shadow of a photographer (right) is caught watching the perfect launch of the Boeing Delta II rocket in the background after it lifted off at 11:44 a.m. EDT. The rocket carries NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, which was developed to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99padig003

NASA Image and Video Library

1999-06-24

KENNEDY SPACE CENTER, FLA. -- Against a light summer sky, the Boeing Delta II rocket carrying NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite roars into the atmosphere after liftoff at 11:44 a.m. EDT from Launch Pad 17A, Cape Canaveral Air Station. FUSE was developed to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0741

NASA Image and Video Library

1999-06-24

As light peers over the horizon at the crack of dawn, NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite waits for launch on Launch Pad 17A, Cape Canaveral Air Station, aboard the Boeing Delta II rocket. Liftoff is scheduled for 11:39 a.m. EDT. FUSE was developed to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

Workers at CCAS attach solar panel to FUSE satellite.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), workers get ready to move a solar panel to be attached to NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite in the background. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket.

KSC-99pp0688

NASA Image and Video Library

1999-06-14

Workers at Hangar AE, Cape Canaveral Air Station (CCAS), adjust the canister segments they are installing around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is being prepared for its transfer to Launch Pad 17A, CCAS, and its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0689

NASA Image and Video Library

1999-06-14

Workers at Hangar AE, Cape Canaveral Air Station (CCAS), fit the second row of canister segments around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is being prepared for its transfer to Launch Pad 17A, CCAS, and its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0687

NASA Image and Video Library

1999-06-14

At Hangar AE, Cape Canaveral Air Station (CCAS), workers move segments of the canister that will be installed around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite in the background. The satellite is being prepared for its transfer to Launch Pad 17A, CCAS, and its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0693

NASA Image and Video Library

1999-06-14

At Hangar AE, Cape Canaveral Air Station (CCAS), workers on scaffolding pull down a weather-proofing cover over the canister surrounding NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite will next be moved to Launch Pad 17A, CCAS, for its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0692

NASA Image and Video Library

1999-06-14

At Hangar AE, Cape Canaveral Air Station (CCAS), the last segment is lifted over the top of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite already encased in a protective canister. The satellite will next be moved to Launch Pad 17A, CCAS, for its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite is fitted with another row of canister segments before being moved to Launch Pad 17A, CCAS. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 aboard a Boeing Delta II rocket.

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), workers move segments of the canister that will be installed around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite in the background. The satellite is being prepared for its transfer to Launch Pad 17A, CCAS, and its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), the last segment is lifted over the top of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite already encased in a protective canister. The satellite will next be moved to Launch Pad 17A, CCAS, for its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

The Universe at Ultraviolet Wavelengths: The first two years of International Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Chapman, R. D. (Editor)

1981-01-01

Highlights of the results obtained from the IUE satellite are addressed. specific topics discussed include the solar system, O-A stars, F-M stars, binary stars and highly evolved objects, nebulae and interstellar medium, and extragalactic objects. Data reduction techniques employed in the analysis of the varied data are also discussed.

Pre-phase A: Development of a far-ultraviolet photometric- and spectroscopic-survey small-explorer experiment

NASA Technical Reports Server (NTRS)

Martin, Christopher

1993-01-01

We propose to perform a far ultraviolet photometric and spectroscopic survey covering the lambda lambda 1300-2000 band with a sensitivity comparable to that of the Palomar Sky Survey. This survey will proceed in three phases: an all-sky survey in three bands to 18-19.5(sup m), deep surveys of selected targets of interest in the same bands to 21-22(sup m), and a spectroscopic survey of 2 percent of the sky to 18(sup m) with a resolution of 3-20A. This mission, the Joint Ultraviolet Nightsky Observer (JUNO), can be performed by a Small-Explorer-class satellite.

Quasi-isotropic VHF antenna array design study for the International Ultraviolet Explorer satellite

NASA Technical Reports Server (NTRS)

Raines, J. K.

1975-01-01

Results of a study to design a quasi-isotropic VHF antenna array for the IUE satellite are presented. A free space configuration was obtained that has no nulls deeper than -6.4 dbi in each of two orthogonal polarizations. A computer program named SOAP that analyzes the electromagnetic interaction between antennas and complicated conducting bodies, such as satellites was developed.

Observations and analysis activities of the International Ultraviolet Explorer satellite telescope

NASA Technical Reports Server (NTRS)

Shull, J. Michael

1996-01-01

The funds from this grant were used to support observations and analysis with the International Ultraviolet Explorer (IUE) satellite telescope. The main area of scientific research concerned the variability analyses of ultraviolet spectra of Active Galactic Nuclei, primarily quasars, Seyfert galaxies, and BL Lacertae objects. The Colorado group included, at various times, the P.I. (J.M. Shull), Research Associate Dr. Rick Edelson, and graduate students Jon Saken, Elise Sachs, and Steve Penton. A portion of the work was also performed by CU undergraduate student Cheong-ming Fu. A major product of the effort was a database of all IUE spectra of active galactic nuclei. This database is being analyzed to obtain spectral indices, line fluxes, and continuum fluxes for over 500 AGN. As a by-product of this project, we implemented a new, improved technique of spectral extraction of IUE spectra, which has been used in several AGN-WATCH campaigns (on the Seyfert galaxy NGC 4151 and on the BL Lac object PKS 2155-304).

KSC-99pp0690

NASA Image and Video Library

1999-06-14

NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite is fitted with another row of canister segments before being moved to Launch Pad 17A, CCAS. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 aboard a Boeing Delta II rocket

KSC-99pp0663

NASA Image and Video Library

1999-06-12

At Hangar AE, Cape Canaveral Air Station (CCAS), workers attach a solar panel to NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

KSC-99pp0668

NASA Image and Video Library

1999-06-12

NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite stands in the Hangar A&E, Cape Canaveral Air Station (CCAS), ready for its launch, targeted for June 23 from Launch Pad 17A, CCAS aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

The FUSE satellite is encased in a canister before being moved to the Launch Pad.

NASA Technical Reports Server (NTRS)

1999-01-01

At Hangar AE, Cape Canaveral Air Station (CCAS), workers get ready to finish erecting the canister around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite at left. At right is the last segment which will be placed on the top. The satellite will next be moved to Launch Pad 17A, CCAS, for its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum.

KSC-99pp0691

NASA Image and Video Library

1999-06-14

At Hangar AE, Cape Canaveral Air Station (CCAS), workers get ready to finish erecting the canister around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite at left. At right is the last segment which will be placed on the top. The satellite will next be moved to Launch Pad 17A, CCAS, for its scheduled launch June 23 aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99padig002

NASA Image and Video Library

1999-06-24

KENNEDY SPACE CENTER, FLA. -- A fireball erupts under the Boeing Delta II rocket, amid clouds of smoke and steam, as it lifts off from Launch Pad 17A, Cape Canaveral Air Station, at 11:44 a.m. EDT. The shadow of a photographer (right) is caught watching the perfect launch. The rocket carries NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, which was developed to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0665

NASA Image and Video Library

1999-06-12

At Hangar AE, Cape Canaveral Air Station (CCAS), workers check the installation of a solar panel on NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

KSC-99pp0666

NASA Image and Video Library

1999-06-12

Workers at Hangar AE, Cape Canaveral Air Station (CCAS), get ready to move the scaffolding from around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0664

NASA Image and Video Library

1999-06-12

At Hangar AE, Cape Canaveral Air Station (CCAS), workers move a solar panel toward NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite before attaching it. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

Extreme ultraviolet explorer satellite observation of Jupiter's Io plasma torus

NASA Technical Reports Server (NTRS)

Hall, D. T; Gladstone, G. R.; Moos, H. W.; Bagenal, F.; Clarke, J. T.; Feldman, P. D.; Mcgrath, M. A.; Schneider, N. M.; Shemansky, D. E.; Strobel, D. F.

1994-01-01

We present the first Extreme Ultraviolet Explorer (EUVE) satellite observation of the Jupiter system, obtained during the 2 day period 1993 March 30 through April 1, which shows a rich emission-line spectrum from the Io plasma torus spanning wavelengths 370 to 735 A. The emission features correspond primarily to known multiplets of oxygen and sulfur ions, but a blended feature near 372 A is a plausible Na II transition. The summed detected energy flux of (7.2 +/- 0.2) x 10(exp -11) ergs/sq cm(s) corresponds to a radiated power of approximately equal to 4 x 10(exp 11) W in this spectral range. All ansa emissions show a distinct dawn-dusk brightness asymmetry and the measured dusk/dawn ratio of the bright S III lambda-680 feature is 2.3 +/- 0.3, significantly larger than the ratio measured by the Voyager spacecraft ultraviolet (UV) instruments. A preliminary estimate of ion partitioning indicates that the oxygen/sulfur ion ratio is approximately equal to 2, compared to the value approximately equal to 1.3 measured by Voyager, and that (Na(+))/(e) greater than 0.01.

Ultraviolet analysis of the peculiar supergiant HD 112374 = HR 4912

NASA Technical Reports Server (NTRS)

Bohm-Vitense, E.; Proffitt, C.

1984-01-01

The ultraviolet energy distribution of the metal-poor supergiant HD 112374 is analyzed based on observations from the International Ultraviolet Explorer (IUE) satellite for the region between 1200 and 2000 A. A discontinuity was found in the UV spectra at 2600 A which confirmed the low-abundance of heavy elements found by Luck et al. (1983). Values for effective temperature and log g in HD112374 were consistent with the star being a very luminous Population II semi-regular variable. The full observational results are presented in a table.

Unusual satellite data: A black hole?. [International Ultraviolet Explorer observations

NASA Technical Reports Server (NTRS)

1978-01-01

Data obtained by the NASA-launched European Space Agency's International Ultraviolet Explorer satellite suggests the possibility of a massive black hole at the center of some globular clusters (star groups) in our galaxy. Six of these clusters, three of them X-ray sources, were closely examined. Onboard short wavelength UV instrumentation penetrated the background denseness of the clusters 15,000 light years away where radiation, probably from a group of 10 to 20 bright blue stars orbiting the core, was observed. The stars may well be orbiting a massive black hole the size of 1,000 solar systems. The existence of the black hole is uncertain. The dynamics of the stars must be studied first to determine how they rotate in relation to the center of the million-star cluster. This may better indicate what provides the necessary gravitational pull that holds them in orbit.

The FUSE satellite is ready to move to the launch pad.

NASA Technical Reports Server (NTRS)

1999-01-01

Standing in Hangar AE, Cape Canaveral Air Station (CCAS) is NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The black rectangle on top is the optical port; at the lower right is the solar panel; behind (left) the lower edge of the panel are the radiators. The total length of the instrument is approximately four meters. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. Launch is targeted for June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket.

The FUSE satellite is ready to move to the launch pad.

NASA Technical Reports Server (NTRS)

1999-01-01

In Hangar AE, Cape Canaveral Air Station (CCAS), NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite stands ready to be moved to the launch pad. The black rectangle on top is the optical port; at the lower edge are the radiators. The total length of the instrument is approximately four meters. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe - hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. Launch is targeted for June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket.

KSC-99pp0662

NASA Image and Video Library

1999-06-12

At Hangar AE, Cape Canaveral Air Station (CCAS), workers get ready to move a solar panel to be attached to NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite in the background. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is targeted for launch June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

KSC-99pp0654

NASA Image and Video Library

1999-06-07

The second stage of a Boeing Delta II rocket is lifted up the launch tower at Launch Pad 17A, Cape Canaveral Air Station (CCAS). The first and second stages will be mated for the launch, targeted on June 23 at CCAS, of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite,. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0655

NASA Image and Video Library

1999-06-07

The second stage of a Boeing Delta II rocket is moved inside the launch tower at Launch Pad 17A, Cape Canaveral Air Station (CCAS). The first and second stages will be mated for the launch, targeted on June 23 at CCAS, of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

Observations of the Magnetic Cataclysmic Variable VV Puppis with the Far Ultraviolet Spectroscopic Explorer

NASA Astrophysics Data System (ADS)

Hoard, D. W.; Szkody, Paula; Ishioka, Ryoko; Ferrario, L.; Gänsicke, B. T.; Schmidt, Gary D.; Kato, Taichi; Uemura, Makoto

2002-10-01

We present the first far-ultraviolet (FUV) observations of the magnetic cataclysmic variable VV Puppis, obtained with the Far Ultraviolet Spectroscopic Explorer satellite. In addition, we have obtained simultaneous ground-based optical photometric observations of VV Pup during part of the FUV observation. The shapes of the FUV and optical light curves are consistent with each other and with those of past observations at optical, extreme-ultraviolet, and X-ray wavelengths. Time-resolved FUV spectra during the portion of VV Pup's orbit when the accreting magnetic pole of the white dwarf can be seen show an increasing continuum level as the accretion spot becomes more directly visible. The most prominent features in the spectrum are the O VI λλ1031.9, 1037.6 emission lines. We interpret the shape and velocity shift of these lines in the context of an origin in the accretion funnel near the white dwarf surface. A blackbody function with Tbb>~90,000 K provides an adequate fit to the FUV spectral energy distribution of VV Pup. Based on observations with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by Johns Hopkins University under NASA contract NAS 5-32985.

Natural variability of tropical upper stratospheric ozone inferred from the Atmosphere Explorer backscatter ultraviolet experiment

NASA Technical Reports Server (NTRS)

Frederick, J. E.; Abrams, R. B.; Dasgupta, R.; Guenther, B.

1981-01-01

Analysis of backscattered ultraviolet radiances observed at tropical latitudes by the Atmosphere Explorer-E satellite reveals both annual and semiannual cycles in upper stratospheric ozone. The annual variation dominates the signal at wavelengths which sense ozone primarily above 45 km while below this, to the lowest altitude sensed, 35 km, the semiannual component has comparable amplitude. Comparison of radiance measurements taken with the same instrument at solar minimum during 1976 and solar maximum in 1979 show no significant differences. This suggests that variations in upper stratospheric ozone over the solar cycle are small, although the data presently available do not allow a definite conclusion.

Microchannel plate EUV detectors for the Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Siegmund, O. H. W.; Malina, R. F.; Coburn, K.; Werthimer, D.

1984-01-01

The design and operating characteristics of the prototype imaging microchannel plate (MCP) detector for the Extreme Ultraviolet Explorer (EUVE) Satellite are discussed. It is shown that this detector has achieved high position resolution performance (greater than 512 x 512 pixels) and has low (less than one percent) image distortion. In addition, the channel plate scheme used has tight pulse height distributions (less than 40 percent FWHM) for UV radiation and displays low (less than 0.2 cnt/sq cm-s) dark background counting rates. Work that has been done on EUV filters in relation to the envisaged filter and photocathode complement is also described.

KSC-99pp0496

NASA Image and Video Library

1999-05-04

Suspended by a crane in Hangar AE, Cape Canaveral Air Station, NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite is lowered onto a circular Payload Attach Fitting (PAF). FUSE is undergoing a functional test of its systems, plus installation of flight batteries and solar arrays. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched May 27 aboard a Boeing Delta II rocket at Launch Complex 17

KSC-99pp0656

NASA Image and Video Library

1999-06-07

Under the watchful eyes of workers at Launch Pad 17A, Cape Canaveral Air Station (CCAS), the second stage of a Boeing Delta II rocket is lowered toward the first stage below. The first and second stages will be mated for the launch, targeted on June 23 at CCAS, , of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

The extreme ultraviolet explorer archive

NASA Astrophysics Data System (ADS)

Polomski, E.; Drake, J. J.; Dobson, C.; Christian, C.

1993-09-01

The Extreme Ultrviolet Explorer (EUVE) public archive was created to handle the storage, maintenance, and distribution of EUVE data and ancillary documentation, information, and software. Access to the archive became available to the public on July 17, 1992, only 40 days after the launch of the EUVE satellite. A brief overview of the archive's contents and the various methods of access will be described.

Space plasma physics at the Applied Physics Laboratory over the past half-century

NASA Technical Reports Server (NTRS)

Potemra, Thomas A.

1992-01-01

An overview is given of space-plasma experiments conducted at the Applied Physics Laboratory (APL) at Johns Hopkins University including observational campaigns and the instrumentation developed. Specific space-plasma experiments discussed include the study of the radiation environment in the Van Allen radiation belt with solid-state proton detectors. Also described are the 5E-1 satellites which acquired particle and magnetic-field data from earth orbit. The Triad satellite and its magnetometer system were developed for high-resolution studies of the earth's magnetic field, and APL contributions to NASA's Interplanetary Monitoring Platforms are listed. The review mentions the International Ultraviolet Explorer, the Atmosphere Explorer mission, and the Active Magnetic Particle Tracer Explorers mission. Other recent programs reviewed include a high-latitude satellite, contributions to the Voyager mission, and radar studies of space plasmas.

ULTRAVIOLET SPECTROSCOPY OF PQ Gem AND V405 Aur FROM THE HST AND IUE SATELLITES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanad, M. R., E-mail: mrsanad1@yahoo.com

Ultraviolet spectra of two intermediate polars (IPs), PQ Gem and V405 Aur, observed with Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph and Faint Object Spectrograph and International Ultraviolet Explorer (IUE) satellites were analyzed during the period between 1994–2000. We estimated the reddening of the two systems from the 2200 Å feature. Six spectra of the two systems revealing modulations of line fluxes at different times are presented. PQ Gem and V405 Aur are featured by spectral lines in different ionization states. This paper focuses on the third ionized carbon emission line at 1550 Å and the first ionized heliummore » emission line at 1640 Å produced in the optically thin outer region of the accretion curtain for the two systems by calculating spectral line fluxes. From HST and IUE data, we deduced ultraviolet luminosities and ultraviolet accretion rates for the two binary stars. The average temperature of the accretion streams for PQ Gem and V405 Aur are ∼4500 K and 4100 K, respectively. The results reveal that there are modulations in fluxes of spectral lines, ultraviolet luminosities, and ultraviolet accretion rates with time for both systems. These modulations are referred to the changes of both density and temperature as a result of the variations of mass transfer rate from the secondary star to the primary star. The current results are consistent with an accretion curtain model for IPs.« less

KSC-99pp0670

NASA Image and Video Library

1999-06-12

In Hangar AE, Cape Canaveral Air Station (CCAS), NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite stands ready to be moved to the launch pad. The black rectangle on top is the optical port; at the lower edge are the radiators. The total length of the instrument is approximately four meters. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. Launch is targeted for June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

KSC-99pp0495

NASA Image and Video Library

1999-05-04

While a crane lifts NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite, workers at Hangar AE, Cape Canaveral Air Station, help guide it toward the circular Payload Attach Fitting (PAF) in front of it. FUSE is undergoing a functional test of its systems, plus installation of flight batteries and solar arrays. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched May 27 aboard a Boeing Delta II rocket at Launch Complex 17

EUVE observations of the Moon

NASA Technical Reports Server (NTRS)

Gladstone, G. R.; Mcdonald, J. S.; Boyd, W. T.

1993-01-01

During its all-sky survey, the Extreme Ultraviolet Explorer (EUVE) satellite observed the Moon several times at first and last quarters, and once near the Dec. 10, 1992 lunar eclipse. We present a preliminary reduction and analysis of this data, in the form of EUV images of the Moon and derived albedos.

Performance of The Far Ultraviolet Spectroscopic Explorer Mirror Assemblies

NASA Technical Reports Server (NTRS)

Ohi, Raymond G.; Barkhouser, Robert H.; Conard, Steven J.; Friedman, Scott D.; Hampton, Jeffery; Moos, H. Warren; Nikulla, Paul; Oliveira, Cristina M.; Saha, Timo T.; Obenschain, Arthur (Technical Monitor)

2000-01-01

The Far Ultraviolet Spectroscopic Explorer is a NASA astrophysics satellite which produces high-resolution spectra in the far-ultraviolet (90.5-118.7 nm bandpass) using a high effective area and low background detectors. The observatory was launched on its three-year mission from Cape Canaveral Air Station on 24 June 1999. The instrument contains four coaligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographically ruled diffraction gratings and delay line microchannel plate detectors. The telescope mirrors have a 352 x 387 mm aperture and 2245 mm focal length and are attached to actuator assemblies, which provide on-orbit, tip, tilt, and focus control. Two mirrors are coated with silicon carbide (SiC) and two are coated with lithium fluoride over aluminum (Al:LiF). We describe mirror assembly in-flight optical and mechanical performance. On-orbit measurements of the far-ultraviolet point spread function associated with each mirror are compared to expectations based on pre-flight laboratory measurements and modeling using the Optical Surface Analysis Code and surface metrology data. On-orbit imaging data indicate that the mirrors meet their instrument-level requirement of 50 percent and 95 percent slit transmission for the high- and mid-resolution spectrograph entrance slits, respectively. The degradation of mirror reflectivity during satellite integration and test is also discussed. The far-ultraviolet reflectivity of the SiC- and AlLiF-coated mirrors decreased about six percent and three percent, respectively, between coating and launch. Each mirror is equipped with three actuators, which consist of a stepper motor driving a ball screw via a two-stage planetary gear train. We also discuss the mechanical performance of the mirror assemblies, including actuator performance and thermal effects.

Ultraviolet properties of individual hot stars in globular cluster cores. 1: NGC 1904 (M 79)

NASA Technical Reports Server (NTRS)

Altner, Bruce; Matilsky, Terry A.

1992-01-01

As part of an observing program using the International Ultraviolet Explorer (IUE) satellite to investigate the ultraviolet properties of stars found within the cores of galactic globular clusters with blue horizontal branches (HBs), we obtained three spectra of the cluster NGC 1904 (M 79). All three were long integration-time, short-wavelength (SWP) spectra obtained at the so called 'center of light' and all three showed evidence of sources within the IUE large aperture (21.4 in. by 10 in.). In this paper we shall describe the analysis of these spectra and present evidence that the UV sources represent individual hot stars in the post-HB stage of evolution.

KSC-99pp0494

NASA Image and Video Library

1999-05-03

Workers at Hangar AE, Cape Canaveral Air Station, maneuver an overhead crane toward NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite standing between vertical workstands. The crane will lift FUSE to move it onto the Payload Attach Fitting (PAF) in front of it. FUSE is undergoing a functional test of its systems, plus installation of flight batteries and solar arrays. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched May 27 aboard a Boeing Delta II rocket at Launch Complex 17

KSC-99pp0669

NASA Image and Video Library

1999-06-12

Standing in Hangar AE, Cape Canaveral Air Station (CCAS) is NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The black rectangle on top is the optical port; at the lower right is the solar panel; behind (left) the lower edge of the panel are the radiators. The total length of the instrument is approximately four meters. FUSE was developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., to investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. Launch is targeted for June 23 from Launch Pad 17A, CCAS, aboard a Boeing Delta II rocket

Extreme ultraviolet reflectivity studies of gold on glass and metal substrates

NASA Technical Reports Server (NTRS)

Jelinsky, Sharon R.; Malina, Roger F.; Jelinsky, Patrick

1988-01-01

The paper reports measurements of the extreme ultraviolet reflectivity of gold from 44 to 920 A at grazing incidence. Gold was deposited using vacuum evaporation and electroplating on substrates of glass and polished nickel, respectively. Measurements are also presented of the extreme ultraviolet reflectivity of electroless nickel in the same wavelength region, where one of the polished nickel substrates was used as a sample. Derived optical constants for evaporated and electroplated gold and electroless nickel are presented. Additional studies of the effects of various contaminants on the EUV reflectivity are also reported. The variations of the optical constants are discussed in terms of density variations, surface roughness and contamination effects. These results ae reported as part of studies for the Extreme Ultraviolet Explorer satellite program to determine acceptance criteria for the EUV optics, contamination budgets and calibration plans.

Ultraviolet light curves of beta Lyrae: Comparison of OAO A-2, IUE, and Voyager Observations

NASA Technical Reports Server (NTRS)

Kondo, Yoji; Mccluskey, George E.; Silvis, Jeffery M. S.; Polidan, Ronald S.; Mccluskey, Carolina P. S.; Eaton, Joel A.

1994-01-01

The six-band ultraviolet light curves of beta Lyrae obtained with the Orbiting Astronomical Observatory (OAO) A-2 in 1970 exhibited a very unusual behavior. The secondary minimum deepened at shorter wavelength, indicating that one was not observing light variations caused primarily by the eclipses of two stars having a roughly Planckian energy distribution. It was then suggested that the light variations were caused by a viewing angle effect of an optically thick, ellipsoidal circumbinary gas cloud. Since 1978 beta Lyrae has been observed with the International Ultraviolet Explorer (IUE) satellite. We have constructed ultraviolet light curves from the IUE archival data for comparison with the OAO A-2 results. We find that they are in substantial agreement with each other. The Voyager ultraviolet spectrometer was also used to observe this binary during a period covered by IUE observations. The Voyager results agree with those of the two other satellite observatories at wavelengths longer than about 1350 A. However, in the wavelength region shorter than the Lyman-alpha line at 1216 A, the light curves at 1085 and 965 A show virtually no light variation except an apparent flaring near phase 0.7, which is also in evidence at longer wavelengths. We suggest that the optically thick circumbinary gas cloud, which envelops the two stars completely, assumes a roughly spherical shape when observed at these shorter wavelengths.

An Autonomous Navigation Algorithm for High Orbit Satellite Using Star Sensor and Ultraviolet Earth Sensor

PubMed Central

Baohua, Li; Wenjie, Lai; Yun, Chen; Zongming, Liu

2013-01-01

An autonomous navigation algorithm using the sensor that integrated the star sensor (FOV1) and ultraviolet earth sensor (FOV2) is presented. The star images are sampled by FOV1, and the ultraviolet earth images are sampled by the FOV2. The star identification algorithm and star tracking algorithm are executed at FOV1. Then, the optical axis direction of FOV1 at J2000.0 coordinate system is calculated. The ultraviolet image of earth is sampled by FOV2. The center vector of earth at FOV2 coordinate system is calculated with the coordinates of ultraviolet earth. The autonomous navigation data of satellite are calculated by integrated sensor with the optical axis direction of FOV1 and the center vector of earth from FOV2. The position accuracy of the autonomous navigation for satellite is improved from 1000 meters to 300 meters. And the velocity accuracy of the autonomous navigation for satellite is improved from 100 m/s to 20 m/s. At the same time, the period sine errors of the autonomous navigation for satellite are eliminated. The autonomous navigation for satellite with a sensor that integrated ultraviolet earth sensor and star sensor is well robust. PMID:24250261

An autonomous navigation algorithm for high orbit satellite using star sensor and ultraviolet earth sensor.

PubMed

Baohua, Li; Wenjie, Lai; Yun, Chen; Zongming, Liu

2013-01-01

An autonomous navigation algorithm using the sensor that integrated the star sensor (FOV1) and ultraviolet earth sensor (FOV2) is presented. The star images are sampled by FOV1, and the ultraviolet earth images are sampled by the FOV2. The star identification algorithm and star tracking algorithm are executed at FOV1. Then, the optical axis direction of FOV1 at J2000.0 coordinate system is calculated. The ultraviolet image of earth is sampled by FOV2. The center vector of earth at FOV2 coordinate system is calculated with the coordinates of ultraviolet earth. The autonomous navigation data of satellite are calculated by integrated sensor with the optical axis direction of FOV1 and the center vector of earth from FOV2. The position accuracy of the autonomous navigation for satellite is improved from 1000 meters to 300 meters. And the velocity accuracy of the autonomous navigation for satellite is improved from 100 m/s to 20 m/s. At the same time, the period sine errors of the autonomous navigation for satellite are eliminated. The autonomous navigation for satellite with a sensor that integrated ultraviolet earth sensor and star sensor is well robust.

Research studies with the International Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

1991-01-01

The IUE research studies comprises 118 separate research programs involving observations, data analysis, and research conducted of the IUE satellite and the NASA Astrophysics Data Program. Herein are presented 92 programs. For each program there is a title, program ID, name of the investigator, statement of work, summary of results, and list of publications.

Improving Assessment of Lifetime Solar Ultraviolet Radiation Exposure in Epidemiologic Studies: Comparison of Ultraviolet Exposure Assessment Methods in a Nationwide United States Occupational Cohort.

PubMed

Little, Mark P; Tatalovich, Zaria; Linet, Martha S; Fang, Michelle; Kendall, Gerald M; Kimlin, Michael G

2018-06-13

Solar ultraviolet radiation is the primary risk factor for skin cancers and sun-related eye disorders. Estimates of individual ambient ultraviolet irradiance derived from ground-based solar measurements and from satellite measurements have rarely been compared. Using self-reported residential history from 67,189 persons in a nationwide occupational US radiologic technologists cohort, we estimated ambient solar irradiance using data from ground-based meters and noontime satellite measurements. The mean distance-moved from city of longest residence in childhood increased from 137.6 km at ages 13-19 to 870.3 km at ages ≥65, with corresponding increases in absolute latitude-difference moved. At ages 20/40/60/80, the Pearson/Spearman correlation coefficients of ground-based and satellite-derived solar potential ultraviolet exposure, using irradiance and cumulative radiant-exposure metrics, were high (=0.87-0.92). There was also moderate correlation (Pearson/Spearman correlation coefficients=0.51-0.60) between irradiance at birth and at last-known address, for ground-based and satellite data. Satellite-based lifetime estimates of ultraviolet radiation were generally 14-15% lower than ground-based estimates, albeit with substantial uncertainties, possibly because ground-based estimates incorporate fluctuations in cloud and ozone, which are incompletely incorporated in the single noontime satellite-overpass ultraviolet value. If confirmed elsewhere, the findings suggest that ground-based estimates may improve exposure-assessment accuracy and potentially provide new insights into ultraviolet-radiation-disease relationships in epidemiologic studies. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Preliminary GPS orbit determination results for the Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Gold, Kenn; Bertiger, Willy; Wu, Sien; Yunck, Tom

1993-01-01

A single-frequency Motorola Global Positioning System (GPS) receiver was launched with the Extreme Ultraviolet Explorer mission in June 1992. The receiver utilizes dual GPS antennas placed on opposite sides of the satellite to obtain full GPS coverage as it rotates during its primary scanning mission. A data set from this GPS experiment has been processed at the Jet Propulsion Laboratory with the GIPSY-OASIS 2 software package. The single-frequency, dual antenna approach and the low altitude (approximately 500 km) orbit of the satellite create special problems for the GPS orbit determination analysis. The low orbit implies that the dynamics of the spacecraft will be difficult to model, and that atmospheric drag will be an important error source. A reduced-dynamic solution technique was investigated in which ad hoc accelerations were estimated at each time step to absorb dynamic model error. In addition, a single-frequency ionospheric correction was investigated, and a cycle-slip detector was written. Orbit accuracy is currently better than 5 m. Further optimization should improve this to about 1 m.

Thin film filter lifetesting results in the extreme ultraviolet

NASA Technical Reports Server (NTRS)

Vedder, P. W.; Vallerga, J. V.; Gibson, J. L.; Stock, J.; Siegmund, O. H. W.

1993-01-01

We present the results of the thin film filter lifetesting program conducted as part of the NASA Extreme Ultraviolet Explorer (EUVE) satellite mission. This lifetesting program is designed to monitor changes in the transmission and mechanical properties of the EUVE filters over the lifetime of the mission (fabrication, assembly, launch and operation). Witness test filters were fabricated from thin film foils identical to those used in the flight filters. The witness filters have been examined and calibrated periodically over the past seven years. The filters have been examined for evidence of pinholing, mechanical degradation, and oxidation. Absolute transmissions of the flight and witness filters have been measured in the extreme ultraviolet (EUV) over six orders of magnitude at numerous wavelengths using the Berkeley EUV Calibration Facility.

A far-ultraviolet atlas of symbiotic stars observed with IUE. 1. The SWP range

NASA Technical Reports Server (NTRS)

Meier, S. R.; Kafatos, M.; Fahey, R. P.; Michalitsianos, A. G.

1994-01-01

This atlas contains sample spectra from the far-ultraviolet observations of 32 symbiotic stars obtained with the International Ultraviolet Explorer (IUE) satellite. In all, 394 low-resolution spectra from the short-wavelength primary (SWP) camera covering the range 1200-2000 A have been extracted from the IUE archive, calibrated, and measured. Absolute line fluxes and wavelengths for the prominent emission lines have been tabulated. Tables of both the general properties of these symbiotics and of features specific to the spectrum of each are included. The spectra shown are representative of the different classes of symbiotic stars that are currently in the IUE archive. These include known eclipsing systems and those that have been observed in outburst (as well as quiescence).

The canister around the FUSE satellite is removed on the pad at CCAS.

NASA Technical Reports Server (NTRS)

1999-01-01

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers check out the protective cover placed over the top of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe.

The discontinuity near 1600 A in the spectra of DA white dwarfs

NASA Technical Reports Server (NTRS)

Wegner, G.

1984-01-01

Ultraviolet spectroscopic observations of two relatively cool DA white dwarfs, L481 - 60 (= WD 1544 - 37) and BPM 1266 ( = WD 2105 - 82), with the International Ultraviolet Explorer (IUE) satellite show a strong drop in their spectral energy distributions below 1600 A. Published model atmospheres and thier visual spectra suggest that these two stars have effective temperatures in the vicinity of 9,000-10,000 K, and it is proposed that the 1600 A feature could be due to the 342(1S) 3s2(1S) photoionization edge of Mg I.

KSC-99pp0380

NASA Image and Video Library

1999-04-05

Workers in Hangar AE, Cape Canaveral Air Station, begin removing the plastic covering from NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite before prelaunch processing. FUSE will undergo a functional test of its systems, followed by installation of the flight batteries and solar arrays. Tests are also scheduled for the communications and data systems linking FUSE with the spacecraft control center at The Johns Hopkins University, Baltimore, Md. FUSE was developed and will be operated by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. The launch aboard a Boeing Delta II rocket is targeted for May 20 at Launch Complex 17

KSC-99pp0382

NASA Image and Video Library

1999-04-05

At Hangar AE, Cape Canaveral Air Station, NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite stands alone after workstands have been removed. As part of prelaunch processing, FUSE will undergo a functional test of its systems, followed by installation of the flight batteries and solar arrays. Tests are also scheduled for the communications and data systems linking FUSE with the spacecraft control center at The Johns Hopkins University, Baltimore, Md. FUSE was developed and will be operated by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. The launch aboard a Boeing Delta II rocket is targeted for May 20 at Launch Complex 17

KSC-99pp0381

NASA Image and Video Library

1999-04-05

At Hangar AE, Cape Canaveral Air Station, NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite is unveiled before prelaunch processing. FUSE will undergo a functional test of its systems, followed by installation of the flight batteries and solar arrays. Tests are also scheduled for the communications and data systems linking FUSE with the spacecraft control center at The Johns Hopkins University, Baltimore, Md. FUSE was developed and will be operated by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. The launch aboard a Boeing Delta II rocket is targeted for May 20 at Launch Complex 17

KSC-99pp0379

NASA Image and Video Library

1999-04-05

Workers in Hangar AE, Cape Canaveral Air Station, get ready to remove the protective shipping cover from NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite for prelaunch processing. FUSE will undergo a functional test of its systems, followed by installation of the flight batteries and solar arrays. Tests are also scheduled for the communications and data systems linking FUSE with the spacecraft control center at The Johns Hopkins University, Baltimore, Md. FUSE was developed and will be operated by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. The launch aboard a Boeing Delta II rocket is targeted for May 20 at Launch Complex 17

KSC-99pp0719

NASA Image and Video Library

1999-06-19

Workers in the launch tower at Launch Pad 17A, Cape Canaveral Air Station, help guide the first segment of the fairing around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is scheduled for launch June 24 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study those elements to unlock the secrets of how galaxies evolve and to discover what the Universe was like when it was only a few minutes old

KSC-99pp0722

NASA Image and Video Library

1999-06-19

At Launch Pad 17A, Cape Canaveral Air Station, NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite (foreground) is partially covered by half of the fairing (behind it) that will protect it during launch. The satellite is scheduled for launch June 24 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study those elements to unlock the secrets of how galaxies evolve and to discover what the Universe was like when it was only a few minutes old

KSC-99pp0717

NASA Image and Video Library

1999-06-19

NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite sits ready for the fairing installation at Launch Pad 17A, Cape Canaveral Air Station. The satellite is scheduled for launch June 24 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe

Recent Goddard Space Flight Center (GSFC) experience with on-orbit calibration of attitude sensors

NASA Technical Reports Server (NTRS)

Davis, W.; Hashmall, J.; Harman, R.

1992-01-01

The results of on-orbit calibration for several satellites by the flight Dynamics Facility (FDF) at GSFC are reviewed. The examples discussed include attitude calibrations for sensors, including fixed-head star trackers, fine sun sensors, three-axis magnetometers, and inertial reference units taken from recent experience with the Compton Gamma Ray observatory, the Upper Atmosphere Research Satellite, and the Extreme Ultraviolet Explorer calibration. The methods used and the results of calibration are discussed, as are the improvements attained from in-flight calibration.

Real-time attitude determination and gyro calibration

NASA Technical Reports Server (NTRS)

Challa, M.; Filla, O.; Sedlak, J.; Chu, D.

1993-01-01

We present results for two real-time filters prototyped for the Compton Gamma Ray Observatory (GRO), the Extreme Ultraviolet Explorer (EUVE), the Cosmic Background Explorer (COBE), and the next generation of Geostationary Operational Environmental Satellites (GOES). Both real and simulated data were used to solve for attitude and gyro biases. These filters promise advantages over single-frame and batch methods for missions like GOES, where startup and transfer-orbit operations require quick knowledge of attitude and gyro biases.

A Search for Metal Lines in the Spectra of DA White Dwarfs

NASA Technical Reports Server (NTRS)

Wegner, G. A.

1986-01-01

A theoretical analysis was carried out in order to interpret the ultraviolet spectra of DB white dwarfs obtained earlier with the International Ultraviolet Explorer (IUE) satellite. Here the results of the IUE ultraviolet spectroscopy combined with visual data and model atmospheres of DB white dwarfs are reported. In particular, a search for spectra lines due to the element carbon using the ultraviolet was made. In no case is there a positive detection of carbon and from these data, and upper limits for carbon by number relative to helium are derived in the range of C: He 10 to the minus 5 power to 10 to the minus 7 power for the 16 DB stars with ultraviolet spectra in the temperature range 11400 K T sub EFF less than 2300 K. The low carbon abundances found in the atmospheres of the DB stars agree well with the hypothesis that the atmospheric carbon observed in the cooler DQ members of the helium-rich white dwarf sequence is produced by a convective dredging mechanism.

Expected scientific performance of the three spectrometers on the extreme ultraviolet explorer

NASA Technical Reports Server (NTRS)

Vallerga, J. V.; Jelinsky, P.; Vedder, P. W.; Malina, R. F.

1990-01-01

The expected in-orbit performance of the three spectrometers included on the Extreme Ultraviolet Explorer astronomical satellite is presented. Recent calibrations of the gratings, mirrors and detectors using monochromatic and continuum EUV light sources allow the calculation of the spectral resolution and throughput of the instrument. An effective area range of 0.2 to 2.8 sq cm is achieved over the wavelength range 70-600 A with a peak spectral resolution (FWHM) of 360 assuming a spacecraft pointing knowledge of 10 arc seconds (FWHM). For a 40,000 sec observation, the average 3 sigma sensitivity to a monochromatic line source is 0.003 photons/sq cm s. Simulated observations of known classes of EUV sources, such as hot white dwarfs, and cataclysmic variables are also presented.

Performance of the Far Ultraviolet Spectroscopic Explorer mirror assemblies

NASA Astrophysics Data System (ADS)

Ohl, Raymond G.; Barkhouser, Robert H.; Conard, Steven J.; Friedman, Scott D.; Hampton, Jeffrey; Moos, H. Warren; Nikulla, Paul; Oliveira, Cristina M.; Saha, Timo T.

2000-12-01

The Far Ultraviolet Spectroscopic Explorer is a NASA astrophysics satellite which produces high-resolution spectra in the far-ultraviolet (90.5 - 118.7 nm bandpass) using a high effective area and low background detectors. The observatory was launched on its three-year mission from Cape Canaveral Air Station on 24 June 1999. The instrument contains four co- aligned, normal incidence, off-axis parabolic mirrors which illuminate separate Rowland circle spectrograph channels equipped with holographically ruled diffraction gratings and delay line microchannel plate detectors. The telescope mirrors have a 352 X 387 mm aperture and 2245 mm focal length and are attached to actuator assemblies, which provide on-orbit, tip, tilt, and focus control. Two mirrors are coated with silicon carbide (SiC) and two are coated with lithium fluoride over aluminum (Al:LiF). We describe mirror assembly in-flight optical and mechanical performance. On-orbit measurements of the far-ultraviolet point spread function associated with each mirror are compared to expectations based on pre-flight laboratory measurements and modeling using the Optical Surface Analysis Code and surface metrology data. On-orbit imaging data indicate that the mirrors meet their instrument-level requirement of 50% and 95% slit transmission for the high- and mid-resolution spectrograph entrance slits, respectively. The degradation of mirror reflectivity during satellite integration and test is also discussed. The FUV reflectivity of the SiC- and Al:LiF-coated mirrors decreased about 6% and 3%, respectively, between coating and launch. Each mirror is equipped with three actuators, which consist of a stepper motor driving a ball screw via a two-stage planetary gear train. We also discuss the mechanical performance of the mirror assemblies, including actuator performance and thermal effects.

KSC-99pp0653

NASA Image and Video Library

1999-06-04

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the launch tower again encircles the Boeing Delta II rocket after being mated with its solid rocket boosters. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) on June 23 at CCAS. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0649

NASA Image and Video Library

1999-06-04

A solid rocket booster arrives at Launch Pad 17A, Cape Canaveral Air Station (CCAS), where it will be mated with the Boeing Delta II rocket in the background. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) on June 23 at CCAS. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0651

NASA Image and Video Library

1999-06-04

Two solid rocket boosters are lifted up the tower on Launch Pad 17A, Cape Canaveral Air Station (CCAS), to be mated with a Boeing Delta II rocket. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) on June 23 at CCAS. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0652

NASA Image and Video Library

1999-06-04

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers check the solid rocket boosters overhead being mated with the Boeing Delta II rocket already in place. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) on June 23 at CCAS. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

KSC-99pp0647

NASA Image and Video Library

1999-06-03

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is moved into the tower. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe ¾ hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS

KSC-99pp0650

NASA Image and Video Library

1999-06-04

A Boeing Delta II rocket sits on Launch Pad 17A, Cape Canaveral Air Station (CCAS), waiting to be mated with its solid rocket boosters. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) on June 23 at CCAS. Developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md., FUSE will investigate the origin and evolution of the lightest elements in the universe hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum

Analysis of the IUE spectra of the strongly interacting binary beta Lyrae

NASA Technical Reports Server (NTRS)

Mccluskey, George E., Jr.

1993-01-01

The six-band ultraviolet light curves of beta Lyrae obtained with the Orbiting Astronomical Observatory A-2 in 1970 exhibited a very unusual behavior. The secondary minimum deepened at shorter wavelength, indicating that one was not observing light variations caused primarily by the eclipses of two stars having a roughly Planckian energy distribution. It was then suggested that the light variations were caused by a viewing angle effect of an optically-thick, ellipsoidal circumbinary gas cloud. Since 1978 beta Lyrae has been observed with the International Ultraviolet Explorer (IUE) satellite. We have constructed ultraviolet light curves from the IUE archival data for comparison with the OAO-A2 results. We find that they are in substantial agreement with each other. The Voyager ultraviolet spectrometer was also used to observe this binary during a period covered by IUE observations. The Voyager results agree with those of the two other satellite observatories at wavelengths longer than about 1350 A. However, in the wavelength region shorter than the Lyman-alpha line at 1216 A, the light curves at 1085 A and 965 A show virtually no light variation except an apparent flaring near phase 0.7, which is also in evidence at longer wavelengths. We suggest that the optically-thick circumbinary gas cloud, which envelops the two stars completely, assumes a roughly spherical shape when observed at these shorter wavelengths.

KSC-99pp0702

NASA Image and Video Library

1999-06-17

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers check out the protective cover placed over the top of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe

A constraint-logic based implementation of the coarse-grained approach to data acquisition scheduling of the International Ultraviolet Explorer orbiting observatory

NASA Technical Reports Server (NTRS)

Mccollum, Bruce; Graves, Mark

1994-01-01

The International Ultraviolet Explorer (IUE) satellite observatory has been in operation continuously since 1978. It typically carries out several thousand observations per year for over a hundred different science projects. These observations, which can occur in one of four different data-taking modes, fall under several satellite-related constraints and many other constraints which derive from the science goals of the projects being undertaken. One strategy which has made the scheduling problem tractable has been that of 'coarse-graining' the time into discrete blocks of equal size (8 hours), each of which is devoted to a single science program, and each of which is sufficiently long for several observations to be carried out. We call it 'coarse-graining' because the schedule is done at a 'coarse' level which ignores fine structure; i.e., no attempt is made to plan the sequence of observations occurring within each time block. We have incorporated the IUE's coarse-grained approach in new software which examines the science needs of the observations and produces a limited set of alternative schedules which meet all of the instrument and science-related constraints. With this algorithm, the IUE can still be scheduled by a single person using a standard workstation, as it has been. We believe that this software could could be adapted to a more complex mission while retaining the IUE's high flexibility and efficiency and scientific return of future satellite missions.

Ultraviolet Spectra of Two Magnetic White Dwarfs and Ultraviolet Spectra of Subluminous Objects Found in the Kiso Schmidt Survey and Ultraviolet Absorptions in the Spectra of DA White Dwarfds

NASA Technical Reports Server (NTRS)

Wegner, Gary A.

1988-01-01

Research under NASA Grant NAG5-287 has carried out a number of projects in conjunction with the International Ultraviolet Explorer (IUE) satellite. These include: (1) studies of the UV spectra of DA white dwarfs which show quasi-molecular bands of H2 and H2(+); (2) the peculiar star HR6560; (3) the UV spectra of two magnetic white dwarfs that also show the quasi-molecular features; (4) investigations of the UV spectra of subluminous stars, primarily identified from visual wavelength spectroscopy in the Kiso survey of UV excess stars, some of which show interesting metal lines in their UV spectra; and (5) completion of studies of UV spectra of DB stars. The main result of this research has been to further knowledge of the structure and compositions of subluminous stars which helps cast light on their formation and evolution.

Contamination control program for the Extreme Ultraviolet Explorer instruments

NASA Technical Reports Server (NTRS)

Ray, David C.; Malina, Roger F.; Welsh, Barry Y.; Austin, James D.; Teti, Bonnie Gray

1989-01-01

A contamination-control program has been instituted for the optical components of the EUV Explorer satellite, whose 80-900 A range performance is easily degraded by particulate and molecular contamination. Cleanliness requirements have been formulated for the design, fabrication, and test phases of these instruments; in addition, contamination-control steps have been taken which prominently include the isolation of sensitive components in a sealed optics cavity. Prelaunch monitoring systems encompass the use of quartz crystal microbalances, particle witness plates, direct flight hardware sampling, and optical witness sampling of EUV scattering and reflectivity.

Alternate charging profiles for the onboard nickel cadmium batteries of the Explorer Platform/Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Rao, Gopalakrishna M.; Prettyman-Lukoschek, Jill S.

1995-01-01

The Explorer Platform/Extreme Ultraviolet Explorer (EP/EUVE) spacecraft power is provided by the Modular Power Subsystems (MPS) which contains three 50 ampere-hour Nickel Cadmium (NiCd) batteries. The batteries were fabricated by McDonnell Douglas Electronics Systems Company, with the cells fabricated by Gates Aerospace Batteries (GAB), Gainesville, Florida. Shortly following launch, the battery performance characteristics showed similar signatures as the anomalous performance observed on both the Upper Atmosphere Research Satellite (UARS) and the Compton Gamma Ray Observatory (CGRO). This prompted the development and implementation of alternate charging profiles to optimize the spacecraft battery performance. The Flight Operations Team (FOT), under the direction of Goddard Space Flight Center's (GSFC) EP/EUVE Project and Space Power Applications Branch have monitored and managed battery performance through control of the battery Charge to Discharge (C/D) ratio and implementation of a Solar Array (SA) offset. This paper provides a brief overview of the EP/EUVE mission, the MPS, the FOT's battery management for achieving the alternate charging profile, and the observed spacecraft battery performance.

Plans for the extreme ultraviolet explorer data base

NASA Technical Reports Server (NTRS)

Marshall, Herman L.; Dobson, Carl A.; Malina, Roger F.; Bowyer, Stuart

1988-01-01

The paper presents an approach for storage and fast access to data that will be obtained by the Extreme Ultraviolet Explorer (EUVE), a satellite payload scheduled for launch in 1991. The EUVE telescopes will be operated remotely from the EUVE Science Operation Center (SOC) located at the University of California, Berkeley. The EUVE science payload consists of three scanning telescope carrying out an all-sky survey in the 80-800 A spectral region and a Deep Survey/Spectrometer telescope performing a deep survey in the 80-250 A spectral region. Guest Observers will remotely access the EUVE spectrometer database at the SOC. The EUVE database will consist of about 2 X 10 to the 10th bytes of information in a very compact form, very similar to the raw telemetry data. A history file will be built concurrently giving telescope parameters, command history, attitude summaries, engineering summaries, anomalous events, and ephemeris summaries.

Imaging characteristics of the Extreme Ultraviolet Explorer microchannel plate detectors

NASA Technical Reports Server (NTRS)

Vallerga, J. V.; Kaplan, G. C.; Siegmund, O. H. W.; Lampton, M.; Malina, R. F.

1989-01-01

The Extreme Ultraviolet Explorer (EUVE) satellite will conduct an all-sky survey over the wavelength range from 70 A to 760 A using four grazing-incidence telescopes and seven microchannel-plate (MCP) detectors. The imaging photon-counting MCP detectors have active areas of 19.6 cm2. Photon arrival position is determined using a wedge-and-strip anode and associated pulse-encoding electronics. The imaging characteristics of the EUVE flight detectors are presented including image distortion, flat-field response, and spatial differential nonlinearity. Also included is a detailed discussion of image distortions due to the detector mechanical assembly, the wedge-and-strip anode, and the electronics. Model predictions of these distortions are compared to preflight calibration images which show distortions less than 1.3 percent rms of the detector diameter of 50 mm before correction. The plans for correcting these residual detector image distortions to less than 0.1 percent rms are also presented.

KSC-03pd0489

NASA Image and Video Library

2003-02-13

KENNEDY SPACE CENTER, FLA. -- The solar array panels on the Galaxy Evolution Explorer (GALEX) satellite are deployed during processing in the Multi-Payload Processing Facility. The GALEX is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0476

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, the GALEX satellite has been moved to a rotation stand. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0488

NASA Image and Video Library

2003-02-13

KENNEDY SPACE CENTER, FLA. - The solar array panels on the Galaxy Evolution Explorer (GALEX) satellite are deployed during processing in the Multi-Payload Processing Facility. The GALEX is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0481

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. - Workers in the Multi-Payload Processing Facility look over the GALEX satellite before solar array testing. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0480

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. - Workers prepare the GALEX satellite for solar array testing in the Multi-Payload Processing Facility. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0490

NASA Image and Video Library

2003-02-13

KENNEDY SPACE CENTER, FLA. -- The solar array panels on the Galaxy Evolution Explorer (GALEX) satellite are deployed during processing in the Multi-Payload Processing Facility. The GALEX is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0479

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- The GALEX satellite is rotated to vertical again for solar array testing in the Multi-Payload Processing Facility. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0477

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, a worker inspects the GALEX satellite after its rotation on a stand. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0478

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, a worker checks over the GALEX satellite on a rotation stand. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-99pp0646

NASA Image and Video Library

1999-06-03

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is raised for its journey up the launch tower. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe ¾ hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS

KSC-99pp0648

NASA Image and Video Library

1999-06-03

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is ready to be lifted into the tower. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe ¾ hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS

KSC-99pp0645

NASA Image and Video Library

1999-06-03

After its arrival at Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is raised to a vertical position. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe ¾ hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS

Boeing Delta II rocket for FUSE launch arrives at CCAS

NASA Technical Reports Server (NTRS)

1999-01-01

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is moved into the tower. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe, hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS.

Boeing Delta II rocket for FUSE launch arrives at CCAS

NASA Technical Reports Server (NTRS)

1999-01-01

After its arrival at Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is raised to a vertical position. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe, hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS.

Boeing Delta II rocket for FUSE launch arrives at CCAS

NASA Technical Reports Server (NTRS)

1999-01-01

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is raised for its journey up the launch tower. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe, hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS.

Boeing Delta II rocket for FUSE launch arrives at CCAS

NASA Technical Reports Server (NTRS)

1999-01-01

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), the first stage of a Boeing Delta II rocket is ready to be lifted into the tower. The rocket is targeted to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE), developed by The Johns Hopkins University under contract to Goddard Space Flight Center, Greenbelt, Md. FUSE will investigate the origin and evolution of the lightest elements in the universe,hydrogen and deuterium. In addition, the FUSE satellite will examine the forces and process involved in the evolution of the galaxies, stars and planetary systems by investigating light in the far ultraviolet portion of the electromagnetic spectrum. FUSE is scheduled to be launched June 23 at CCAS.

Ultraviolet imaging detectors for the GOLD mission

NASA Astrophysics Data System (ADS)

Siegmund, O. H. W.; McPhate, J.; Curtis, T.; Jelinsky, S.; Vallerga, J. V.; Hull, J.; Tedesco, J.

2016-07-01

The GOLD mission is a NASA Explorer class ultraviolet Earth observing spectroscopy instrument that will be flown on a telecommunications satellite in geostationary orbit in 2018. Microchannel plate detectors operating in the 132 nm to 162 nm FUV bandpass with 2D imaging cross delay line readouts and electronics have been built for each of the two spectrometer channels for GOLD. The detectors are "open face" with CsI photocathodes, providing 30% efficiency at 130.4 nm and 15% efficiency at 160.8 nm. These detectors with their position encoding electronics provide 600 x 500 FWHM resolution elements and are photon counting, with event handling rates of > 200 KHz. The operational details of the detectors and their performance are discussed.

Artist concept of Solar Backscatter UV (SBUV) measurement technique on TIROS

NASA Technical Reports Server (NTRS)

1989-01-01

Artist concept titled OZONE MEASUREMENT TECHNIQUE shows how the Solar Backscatter Ultraviolet (UV) 2 (SBUV-2) on the National Oceanic and Atmospheric Administration's (NOAA's) TIROS satellites (NOAA-9 and NOAA-11) works. Ozone is derived from the 'SBUV' instrument from the ratio of the observed backscattered radiance to the solar irradiance in the ultraviolet. This is called the ultraviolet albedo. During STS-34 Shuttle Solar Backscatter Ultraviolet (SSBUV) instruments in Atlantis', Orbiter Vehicle (OV) 104's, payload bay (PLB) will calibrate the instruments onboard the TIROS satellites. SSBUV is managed by Goddard Space Flight Center (GSFC).

Experience from the in-flight calibration of the Extreme Ultraviolet Explorer (EUVE) and Upper Atmosphere Research Satellite (UARS) fixed head star trackers (FHSTs)

NASA Technical Reports Server (NTRS)

Lee, Michael

1995-01-01

Since the original post-launch calibration of the FHSTs (Fixed Head Star Trackers) on EUVE (Extreme Ultraviolet Explorer) and UARS (Upper Atmosphere Research Satellite), the Flight Dynamics task has continued to analyze the FHST performance. The algorithm used for inflight alignment of spacecraft sensors is described and the equations for the errors in the relative alignment for the simple 2 star tracker case are shown. Simulated data and real data are used to compute the covariance of the relative alignment errors. Several methods for correcting the alignment are compared and results analyzed. The specific problems seen on orbit with UARS and EUVE are then discussed. UARS has experienced anomalous tracker performance on an FHST resulting in continuous variation in apparent tracker alignment. On EUVE, the FHST residuals from the attitude determination algorithm showed a dependence on the direction of roll during survey mode. This dependence is traced back to time tagging errors and the original post launch alignment is found to be in error due to the impact of the time tagging errors on the alignment algorithm. The methods used by the FDF (Flight Dynamics Facility) to correct for these problems is described.

Spacelab

NASA Image and Video Library

1990-12-01

In this photograph, the instruments of the Astro-1 Observatory are erected in the cargo bay of the Columbia orbiter. Astro-1 was launched aboard the the Space Shuttle Orbiter Columbia (STS-35) mission on December 2, 1990. The Astro Observatory was designed to explore the universe by observing and measuring the ultraviolet radiation from celestial objects. Astronomical targets of observation selected for Astro missions included planets, stars, star clusters, galaxies, clusters of galaxies, quasars, remnants of exploded stars (supernovae), clouds of gas and dust (nebulae), and the interstellar medium. Astro-1 used a Spacelab pallet system with an instrument pointing system and a cruciform structure for bearing the three ultraviolet instruments mounted in a parallel configuration. The three instruments were:The Hopkins Ultraviolet Telescope (HUT), the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE), and the Ultraviolet Imaging Telescope (UIT). Also in the payload bay was the Broad Band X-Ray Telescope (BBXRT). Scientific return included approximately 1,000 photographs of the ultraviolet sky in the most extensive ultraviolet imagery ever attempted, the longest ultraviolet spectral observation of a comet ever made, and data never before seen on types of active galaxies called Seyfert galaxies. The mission also provided data on a massive supergiant star captured in outburst and confirmed that a spectral feature observed in the interstellar medium was due to graphite. In addition, Astro-1 acquired superb observations of the Jupiter magnetic interaction with one of its satellites.

KSC-99pp0718

NASA Image and Video Library

1999-06-19

At Launch Pad 17A, Cape Canaveral Air Station, workers oversee the lifting of the fairing (right) into the tower. At left is NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite around which the fairing will be fitted. The satellite is scheduled for launch June 24 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe

KSC-99pp0716

NASA Image and Video Library

1999-06-19

A camera is shown mounted on the second stage of the Boeing Delta II rocket scheduled to launch NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite June 24 from Launch Pad 17A, Cape Canaveral Air Station. The camera will record the separation of the fairing encircling the satellite, which should occur several minutes after launch. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe

The canister around the FUSE satellite is removed on the pad at CCAS.

NASA Technical Reports Server (NTRS)

1999-01-01

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers begin to remove the canister around the top of the NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket.

The canister around the FUSE satellite is removed on the pad at CCAS.

NASA Technical Reports Server (NTRS)

1999-01-01

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers oversee the removal of the canister from the top of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket.

The use of satellite data to measure ultraviolet-B penetrance and its potential association with age of multiple sclerosis onset.

PubMed

Amram, Ofer; Schuurman, Nadine; Randall, Ellen; Zhu, Feng; Saeedi, Jameelah; Rieckmann, Peter; Yee, Irene; Tremlett, Helen

2018-04-01

Studies have indicated an association between low Ultraviolet B (UVB) exposure and an increased risk of developing multiple sclerosis (MS). Few studies, however, have explored whether UVB exposure is associated with the age at MS symptom onset. We investigated the potential association between cumulative early life ambient UVB exposure and age at MS onset, using satellite data to measure ambient UVB exposure. Adult onset MS patients were selected from the University of British Columbia's MS genetic database (1980-2005). Patients' places of residence from birth to age 18 years were geocoded (latitude and longitude) and assigned UVB values using NASA's Total Ozone Mapping Spectrometer (TOMS) dataset. Linear regression was used to explore the relationship between cumulative UVB exposure (measured for age periods 0-6, 7-12, 13-18, 0-12, and 0-18) and age at MS onset. 3226 patients were included in the analysis. Of these, 74% were female, with an overall mean symptom onset age of 33.3 years. At onset, a total of 2944 (91%) had a relapsing-remitting disease course, 254 (8%) had primary progressive and the disease course for 28 (1%) was unknown. No significant associations between cumulative early life ambient UVB exposure and age at MS onset were observed. Patient sex, MS phenotype, and immigration to Canada after age 18 were significantly associated with age of onset (p < 0.01). Early life ambient UVB, as measured by satellite imagery, was not significantly associated with the age at MS onset. Copyright © 2018 Elsevier B.V. All rights reserved.

The first UV spectrum of a Uranian satellite - IUE observations of Oberon from 2650-3200 A

NASA Technical Reports Server (NTRS)

Stern, S. A.; Festou, M. C.; Van Santvoort, J.; Buratti, B. J.

1990-01-01

Using the International Ultraviolet Explorer (IUE) observatory, the first vacuum UV spectrum of Oberon was obtained. The data contain useful information in the spectral range 2650-3200 A. Oberon's UV geometric albedo is found to be flat and essentially featureless with an average value of p(UV) = 0.19 + or - 0.025, and making it possible to extend Oberon's phase curve into the opposite region.

A multimission three-axis stabilized spacecraft flight dynamics ground support system

NASA Technical Reports Server (NTRS)

Langston, J.; Krack, K.; Reupke, W.

1993-01-01

The Multimission Three-Axis Stabilized Spacecraft (MTASS) Flight Dynamics Support System (FDSS) has been developed in an effort to minimize the costs of ground support systems. Unlike single-purpose ground support systems, which attempt to reduce costs by reusing software specifically developed for previous missions, the multimission support system is an intermediate step in the progression to a fully generalized mission support system in which numerous missions may be served by one general system. The benefits of multimission attitude ground support systems extend not only to the software design and coding process, but to the entire system environment, from specification through testing, simulation, operations, and maintenance. This paper reports the application of an MTASS FDSS to multiple scientific satellite missions. The satellites are the Upper Atmosphere Research Satellite (UARS), the Extreme Ultraviolet Explorer (EUVE), and the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX). Both UARS and EUVE use the multimission modular spacecraft (MMS) concept. SAMPEX is part of the Small Explorer (SMEX) series and uses a much simpler set of attitude sensors. This paper centers on algorithm and design concepts for a multimission system and discusses flight experience from UARS.

KSC-03pd0484

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0483

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0492

NASA Image and Video Library

2003-02-13

KENNEDY SPACE CENTER, FLA. -- Workers in the Multi-Payload Processing Facility check the solar array panels on the Galaxy Evolution Explorer (GALEX) satellite after they were deployed. The GALEX is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0485

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0482

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0486

NASA Image and Video Library

2003-02-06

KENNEDY SPACE CENTER, FLA. -- In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0491

NASA Image and Video Library

2003-02-13

KENNEDY SPACE CENTER, FLA. - Workers in the Multi-Payload Processing Facility check the solar array panels on the Galaxy Evolution Explorer (GALEX) satellite after they were deployed. The GALEX is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

KSC-03pd0487

NASA Image and Video Library

2003-02-13

KENNEDY SPACE CENTER, FLA. - The Galaxy Evolution Explorer (GALEX) satellite is ready for deployment of its solar array panels during processing in the Multi-Payload Processing Facility. The GALEX is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket.

Remote sensing of the low-latitude daytime ionosphere: ICON simulations and retrievals

NASA Astrophysics Data System (ADS)

Stephan, A. W.; Korpela, E.; England, S.; Immel, T. J.

2016-12-01

The Ionospheric Connection Explorer (ICON) sensor suite includes a spectrograph that will provide altitude profiles of the OII 61.7 and 83.4 nm airglow features, from which the daytime F-region ionosphere can be inferred. To make the connection between these extreme-ultraviolet (EUV) airglow emissions and ionospheric densities, ICON will use a method that has matured significantly in the last decade with the analysis of data from the Remote Atmospheric and Ionospheric Detection System (RAIDS) on the International Space Station, and the Special Sensor Ultraviolet Limb Imager (SSULI) sensors on the Defense Meteorological Satellite Program (DMSP) series of satellites. We will present end-to-end simulations of ICON EUV airglow measurements and data inversion for the expected viewing geometry and sensor capabilities, including noise. While we will focus on the performance of the algorithm for ICON within the context of the current state of knowledge, we will also identify areas where fundamental information can be gained from the high-sensitivity ICON measurements that could be used as feedback to directly improve the overall performance of the algorithm itself.

Galactic interstellar abundance surveys with IUE and IRAS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Steenberg, M.E.

1987-01-01

This thesis is a survey of interstellar densities, abundances, and cloud structure in the Galaxy, using two NASA satellites: the International Ultraviolet Explorer (IUE) and Infrared Astronomical Satellite (IRAS). From IUE high-resolution spectra, the author measured equivalent widths of 18 ultraviolet resonance transitions and derived column densities for Si/sup +/, Mn/sup +/, Fe/sup +/, S/sup +/, and Zn/sup +/ toward 261 early-type stars. From the IRAS all-sky survey he also measured the infrared cirrus flux. He examined the variations of the measured parameters with spectral type, E(B-V), galactic longitude and latitude, distance from the Sun, and mean density. The hydrogen-columnmore » densities, metal-column densities, and gas-to-dust ratio are in good agreement with Copernicus surveys. The derived interstellar abundances yield mean logarithmic depletions. These depletions correlate with mean density but not with the physical density derived from Copernicus H/sub 2/ rotational states. Abundance ratios indicate a larger Fe halo abundance compared to Si, Mn, S, or Zn, which may result from selective grain processing in shocks or from Type I supernovae.« less

It's Not a Bird or a Plane

NASA Technical Reports Server (NTRS)

2005-01-01

Galaxies aren't the only objects filling up the view of NASA's Galaxy Evolution Explorer. Since its launch in 2003, the space telescope -- originally designed to observe galaxies across the universe in ultraviolet light -- has discovered a festive sky blinking with flaring and erupting stars, as well as streaking asteroids, satellites and space debris. One such streaking object -- possibly an Earth-orbiting satellite -- can be seen here flying across the telescope's sight in this sped-up movie.

This probable satellite appears during the last 5 minutes of a 13.5-minute observation. It looks elongated because each picture frame containing the moving object is 19 seconds long. Faint ghost images on either side of the source are detector artifacts caused by the object's extreme brightness.

These bonus objects are being collected in to public catalogues for other astronomers to study.

Bibliographical index of objects observed by IUE

NASA Technical Reports Server (NTRS)

Mead, J. M.; Boggess, A.

1982-01-01

Six astronomical journals were searched and 343 papers describing studies using data obtained with the International Ultraviolet Explorer satellite were identified. From a review of these papers, the names of the astronomical objects discussed were recorded and compiled into a list of 2460 entries, along with each reference, and sorted by object name or catalogue number. This index enables a user to tell immediately where to find published papers describing IUE observation of the objects of interest to him.

Satellite operations support expert system

NASA Technical Reports Server (NTRS)

1985-01-01

The Satellite Operations Support Expert System is an effort to identify aspects of satellite ground support activity which could profitably be automated with artificial intelligence (AI) and to develop a feasibility demonstration for the automation of one such area. The hydrazine propulsion subsystems (HPS) of the International Sun Earth Explorer (ISEE) and the International Ultraviolet Explorer (IUS) were used as applications domains. A demonstration fault handling system was built. The system was written in Franz Lisp and is currently hosted on a VAX 11/750-11/780 family machine. The system allows the user to select which HPS (either from ISEE or IUE) is used. Then the user chooses the fault desired for the run. The demonstration system generates telemetry corresponding to the particular fault. The completely separate fault handling module then uses this telemetry to determine what and where the fault is and how to work around it. Graphics are used to depict the structure of the HPS, and the telemetry values displayed on the screen are continually updated. The capabilities of this system and its development cycle are described.

Contamination control approach for the Extreme Ultraviolet Explorer satellite instrumentation

NASA Technical Reports Server (NTRS)

Mrowka, Stan; Jelinsky, Sharon; Jelinsky, Patrick; Malina, Roger F.

1987-01-01

The Extreme Ultraviolet Explorer will perform an all-sky survey and spectroscopic observations over the wavelength range 80-900A. Hydrocarbon and particulate contamination will potentially affect the throughput and signal to noise ratio of the signal detected by the instruments. A witness sample program is here used to investigate and monitor the effects of specific contaminants on EUV reflectivity. Witness samples were intentionally contaminated with thin layers of pump oil. An oil layer 150 A thick was applied and found to evaporate over 8 hours. The EUV reflectivity and imaging properties were then measured and found to be acceptable for grazing angles between 5 and 30 deg. In a second test, layers 500 A thick were deposited and then allowed to evaporate in vacuum; once the oil had evaporated to at least 350 A, the final sample reflectivity was degraded less than 10 percent, but the image was degraded severely by scattering. An outline of the contamination control program is also presented.

Near-ultraviolet imaging of Jupiter's satellite Io with the Hubble Space Telescope

NASA Technical Reports Server (NTRS)

Paresce, F.; Sartoretti, P.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.; Crane, P.; Deharveng, J. M.; Disney, M. J.; Jakobsen, P.

1992-01-01

The surface of Jupiter's Galilean satellite Io has been resolved for the first time in the near ultraviolet at 2850 A by the Faint Object Camera (FOC) on the Hubble Space Telescope (HST). The restored images reveal significant surface structure down to the resolution limit of the optical system corresponding to approximately 250 km at the sub-earth point.

An operations and command systems for the extreme ultraviolet explorer

NASA Technical Reports Server (NTRS)

Muscettola, Nicola; Korsmeyer, David J.; Olson, Eric C.; Wong, Gary

1994-01-01

About 40% of the budget of a scientific spacecraft mission is usually consumed by Mission Operations & Data Analysis (MO&DA) with MO driving these costs. In the current practice, MO is separated from spacecraft design and comes in focus relatively late in the mission life cycle. As a result, spacecraft may be designed that are very difficult to operate. NASA centers have extensive MO expertise but often lessons learned in one mission are not exploited for other parallel or future missions. A significant reduction of MO costs is essential to ensure a continuing and growing access to space for the scientific community. We are addressing some of these issues with a highly automated payload operations and command system for an existing mission, the Extreme Ultraviolet Explorer (EUVE). EUVE is currently operated jointly by the Goddard Space Flight Center (GSFC), responsible for spacecraft operations, and the Center for Extreme Ultraviolet Astrophysics (CEA) of the University of California, Berkeley, which controls the telescopes and scientific instruments aboard the satellite. The new automated system is being developed by a team including personnel from the NASA Ames Research Center (ARC), the Jet Propulsion Laboratory (JPL) and the Center for EUV Astrophysics (CEA). An important goal of the project is to provide AI-based technology that can be easily operated by nonspecialists in AI. Another important goal is the reusability of the techniques for other missions. Models of the EUVE spacecraft need to be built both for planning/scheduling and for monitoring. In both cases, our modeling tools allow the assembly of a spacecraft model from separate sub-models of the various spacecraft subsystems. These sub-models are reusable; therefore, building mission operations systems for another small satellite mission will require choosing pre-existing modules, reparametrizing them with respect to the actual satellite telemetry information, and reassembling them in a new model. We briefly describe the EUVE mission and indicate why it is particularly suitable for the task. Then we briefly outline our current work in mission planning/scheduling and spacecraft and instrument health monitoring.

Ultraviolet reflectance properties of asteroids

NASA Astrophysics Data System (ADS)

Butterworth, P. S.; Meadows, A. J.

1985-05-01

An analysis of the UV spectra of 28 asteroids obtained with the Internal Ultraviolet Explorer (IUE) satellite is presented. The spectra lie within the range 2100-3200 A. The results are examined in terms of both asteroid classification and of current ideas concerning the surface mineralogy of asteroids. For all the asteroids examined, UV reflectivity declines approximately linearly toward shorter wavelengths. In general, the same taxonomic groups are seen in the UV as in the visible and IR, although there is some evidence for asteroids with anomalous UV properties and for UV subclasses within the S class. No mineral absorption features are reported of strength similar to the strongest features in the visible and IR regions, but a number of shallow absorptions do occur and may provide valuable information on the surface composition of many asteroids.

Ultraviolet Spectra of Comets Observed with the International Ultraviolet Explorer Satellite Observatory.

NASA Astrophysics Data System (ADS)

Weaver, Harold Anthony, Jr.

Ultraviolet spectra of seven comets observed with the International Ultraviolet Explorer (IUE) satellite are presented. Observations of comet Bradfield (1979 X) made in early 1980 allow a comprehensive study of the production of water by this comet. By comparing the observations to the predictions of two water models of the coma (Haser and vectorial), it is determined that these measurements support the idea of a comet composed principally of water ice. The vaporization of the water has a rather unexpected heliocentric variation, decreasing as r('-3.7) over the entire range of observations. Atomic carbon is relatively abundant in the coma of comet Bradfield; the production rate of carbon is roughly 5-10% of the water production rate. Analysis of the spatial brightness profiles of the strongest atomic carbon emission does not reveal the identity of the source of the observed carbon, but the data are apparently inconsistent with a photodissociation source that is either CO or CO(,2). A comparison of the ultraviolet spectrum of periodic comet Encke, recorded by the IUE between 1980 October 24 and November 5, with similar spectra of short and long period comets shows the gaseous composition of P/Encke to be virtually identical to that of the other comets. If P/Encke is indeed the remains of a once giant comet, this similarity implies a homogeneous structure for the cometary ice nucleus. The OH(0,0) band brightness distribution shows a spatial variation similar to the visible fan-shaped image of the comet. Comets P/Tuttle (1980h), P/Stephan-Oterma (1980g), and Meier (1980q) were observed during November-December 1980 with IUE, while comets P/Borrelly (1980i) and Panther (1980u) were observed with IUE on 6 March 1981. The spectra of these comets are compared with those of comets Bradfield (1979 X) and P/Encke, as well as with each other. In order to simplify the interpretation of the data and to minimize the dependence upon a specific model, the spectra are compared at approximately the same value of heliocentric distance whenever possible. Effects due to helicentric velocity, geocentric distance, and optical depth are also discussed. All of the cometary spectra are remarkably similar, which suggests that these comets may have a common composition and origin.

RS CVn binaries: Testing the solar-stellar dynamo connection

NASA Technical Reports Server (NTRS)

Dempsey, R.

1995-01-01

We have used the Extreme Ultraviolet Explorer satellite to study the coronal emission from the EUV-bright RS CVn binaries Sigma2 CrB, observed February 10-21, 1994, and II Peg, observed October 1-5, 1993. We present time-resolved and integrated EUV short-, medium-, and long-wavelength spectra for these binaries. Sigma2 CrB shows significant first-order emission features in the long-wavelength region. The coronal emission distributions and electron densities are estimated for those active coronae dominated by high temperature plasma.

KSC-99pp0720

NASA Image and Video Library

1999-06-19

A worker in the launch tower at Launch Pad 17A, Cape Canaveral Air Station, watches as the first segment of the fairing is maneuvered around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is scheduled for launch June 24 aboard a Boeing Delta II rocket. At the lower left in the photo can be seen a camera installed on the second stage of the rocket to record the separation of the fairing several minutes after launch. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study those elements to unlock the secrets of how galaxies evolve and to discover what the Universe was like when it was only a few minutes old

KSC-99pp0721

NASA Image and Video Library

1999-06-19

Workers in the launch tower at Launch Pad 17A, Cape Canaveral Air Station, help guide the first segment of the fairing around NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The satellite is scheduled for launch June 24 aboard a Boeing Delta II rocket. At the lower left can be seen a camera installed on the second stage of the rocket to record the separation of the fairing several minutes after launch. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study those elements to unlock the secrets of how galaxies evolve and to discover what the Universe was like when it was only a few minutes old

A review of ultraviolet astronomical research with the Copernicus satellite

NASA Technical Reports Server (NTRS)

Snow, T. P., Jr.

1976-01-01

Results of ultraviolet spectrophotometric observations with the satellite Copernicus (OAO-3) are summarized, and are intended to be completely covered through January 1, 1976. Interstellar research recently reviewed elsewhere is not included, although some newer interstellar results are described. A large fraction of the research covered in this review has been carried out by Guest Investigators with Copernicus. A brief description of the spacecraft and its operation is included.

Spatial Distribution of Io's Neutral Oxygen Cloud Observed by Hisaki

NASA Astrophysics Data System (ADS)

Koga, Ryoichi; Tsuchiya, Fuminori; Kagitani, Masato; Sakanoi, Takeshi; Yoneda, Mizuki; Yoshioka, Kazuo; Yoshikawa, Ichiro; Kimura, Tomoki; Murakami, Go; Yamazaki, Atsushi; Smith, H. Todd; Bagenal, Fran

2018-05-01

We report on the spatial distribution of a neutral oxygen cloud surrounding Jupiter's moon Io and along Io's orbit observed by the Hisaki satellite. Atomic oxygen and sulfur in Io's atmosphere escape from the exosphere mainly through atmospheric sputtering. Some of the neutral atoms escape from Io's gravitational sphere and form neutral clouds around Jupiter. The extreme ultraviolet spectrograph called EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) installed on the Japan Aerospace Exploration Agency's Hisaki satellite observed the Io plasma torus continuously in 2014-2015, and we derived the spatial distribution of atomic oxygen emissions at 130.4 nm. The results show that Io's oxygen cloud is composed of two regions, namely, a dense region near Io and a diffuse region with a longitudinally homogeneous distribution along Io's orbit. The dense region mainly extends on the leading side of Io and inside of Io's orbit. The emissions spread out to 7.6 Jupiter radii (RJ). Based on Hisaki observations, we estimated the radial distribution of the atomic oxygen number density and oxygen ion source rate. The peak atomic oxygen number density is 80 cm-3, which is spread 1.2 RJ in the north-south direction. We found more oxygen atoms inside Io's orbit than a previous study. We estimated the total oxygen ion source rate to be 410 kg/s, which is consistent with the value derived from a previous study that used a physical chemistry model based on Hisaki observations of ultraviolet emission ions in the Io plasma torus.

NASA Ames UV-LED Poster Overview

NASA Technical Reports Server (NTRS)

Jaroux, Belgacem Amar

2015-01-01

UV-LED is a small satellite technology demonstration payload being flown on the Saudisat-4 spacecraft that is demonstrating non-contacting charge control of an isolated or floating mass using new solid-state ultra-violet light emitting diodes (UV-LEDs). Integrated to the rest of the spacecraft and launched on a Dnepr in June 19, 2014, the project is a collaboration between the NASA Ames Research Center (ARC), Stanford University, and King Abdulaziz City for Science and Technology (KACST). Beginning with its commissioning in December, 2015, the data collected by UV-LED have validated a novel method of charge control that will improve the performance of drag-free spacecraft allowing for concurrent science collection during charge management operations as well as reduce the mass, power and volume required while increasing lifetime and reliability of a charge management subsystem. UV-LED continues to operate, exploring new concepts in non-contacting charge control and collecting data crucial to understanding the lifetime of ultra-violet light emitting diodes in space. These improvements are crucial to the success of ground breaking missions such as LISA and BBO, and demonstrates the ability of low cost small satellite missions to provide technological advances that far exceed mission costs.

First ultraviolet reflectance measurements of several Kuiper Belt objects, Kuiper Belt object satellites, and new ultraviolet measurements of A Centaur

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stern, S. A.; Schindhelm, E.; Cunningham, N. J., E-mail: astern@swri.edu

We observed the 2600-3200 Å (hereafter, mid-UV) reflectance of two Kuiper Belt Objects (KBOs), two KBO satellites, and a Centaur, using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS). Other than measurements of the Pluto system, these constitute the first UV measurements obtained of KBOs, and KBO satellites, and new HST UV measurements of the Centaur 2060 Chiron. We find significant differences among these objects, constrain the sizes and densities of Haumea's satellites, and report the detection of a possible spectral absorption band in Haumea's spectrum near 3050 Å. Comparisons of these objects to previously published UV reflectance measurementsmore » of Pluto and Charon are also made here.« less

The global distribution of nitric oxide in the thermosphere as determined by the Atmosphere Explorer D satellite

NASA Technical Reports Server (NTRS)

Cravens, T. E.; Gerard, J.-C.; Lecompte, M.; Stewart, A. I.; Rusch, D. W.

1985-01-01

The ultraviolet nitric oxide spectrometer (UVNO) experiment on the Atmosphere Explorer D (AE-D) satellite measured thermospheric nitric oxide during the winter of 1974-1975 using resonant fluorescence from the 1-0 gamma band of the molecule. Almost complete latitude coverage was obtained, but the observations were confined to morning local times close to 0900. The 1-0 gamma band intensity profiles measured by the instrument were inverted to provide vertical profiles of the NO number density between about 90 and 200 km. Typically, the measured NO concentrations reached a maximum between altitudes of 100 and 110 km, and more NO was observed at higher latitudes than at low latitudes, in agreement with previous observational studies. The shape of the NO profile was also found to be a function of latitude, with a plateau appearing in the profile near 130 km for low latitudes and mid-latitudes in the winter hemisphere.

Laboratory Data for X-Ray Astronomy

NASA Technical Reports Server (NTRS)

Beiersdorfer, P.; Brown, G. V.; Chen, H.; Gu, M.-F.; Kahn, S. M.; Lepson, J. K.; Savin, D. W.; Utter, S. B.

2000-01-01

Laboratory facilities have made great strides in producing large sets of reliable data for X-ray astronomy, which include ionization and recombination cross sections needed for charge balance calculations as well as the atomic data needed for interpreting X-ray line formation. We discuss data from the new generation sources and pay special attention to the LLNL electron beam ion trap experiment, which is unique in its ability to provide direct laboratory access to spectral data under precisely controlled conditions that simulate those found in many astrophysical plasmas. Examples of spectral data obtained in the 1-160 A wavelength range are given illustrating the type of laboratory X-ray data produced in support of such missions as Chandra, X-Ray Multi-Mirror telescope (XMM), Advanced Satellite for Cosmology and Astrophysics (ASCA) and Extreme Ultraviolet Explorer Satellite (EUVE).

The Loopy Ultraviolet Line Profiles of RU Lupi: Accretion, Outflows, and Fluorescence

NASA Astrophysics Data System (ADS)

Herczeg, Gregory J.; Walter, Frederick M.; Linsky, Jeffrey L.; Gahm, Gösta F.; Ardila, David R.; Brown, Alexander; Johns-Krull, Christopher M.; Simon, Michal; Valenti, Jeff A.

2005-06-01

We present far-ultraviolet (FUV) spectra of the classical T Tauri star RU Lup covering the 912-1710 Å spectral range, as observed by the Hubble Space Telescope STIS and the Far Ultraviolet Spectroscopic Explorer satellite. We use these spectra, which are rich in emission and absorption lines, to probe both the accreting and outflowing gas. Absorption in the Lyα profile constrains the extinction to AV~0.07 mag, which we confirm with other diagnostics. We estimate a mass accretion rate of (5+/-2)×10-8 Msolar yr-1 using the optical-NUV accretion continuum. The accreting gas is also detected in bright, broad lines of C IV, Si IV, and N V, which all show complex structures across the line profile. Many other emission lines, including those of H2 and Fe II, are pumped by Lyα. RU Lup's spectrum varies significantly in the FUV; our STIS observations occurred when RU Lup was brighter than several other observations in the FUV, possibly because of a high mass accretion rate.

KSC-99pp0701

NASA Image and Video Library

1999-06-17

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers remove another section of the canister surrounding NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket

Laboratory spectroscopy and space astrophysics: A tribute to Joe Reader

NASA Astrophysics Data System (ADS)

Leckrone, David S.

2013-07-01

Beginning with the launch of the Copernicus Satellite in 1973, and continuing with the International Ultraviolet Explorer (IUE), and the state-of-the-art spectrographs on the Hubble Space Telescope (GHRS, FOS, STIS and COS), astrophysics experienced dramatic advancements in capabilities to study the composition and physical properties of planets, comets, stars, nebulae, the interstellar medium, galaxies, quasars and the intergalactic medium at visible and ultraviolet wavelengths. It became clear almost immediately that the available atomic data needed to calibrate and quantitatively analyze these superb spectroscopic observations, obtained at great cost from space observatories, was not up to that task. Over the past 3+ decades, Joe Reader and his collaborators at NIST have provided, essentially "on demand", laboratory observations and analyses of extraordinary quality to help astrophysicists extract the maximum possible physical understanding of objects in the cosmos from their space observations. This talk is one scientist's grateful retrospective about these invaluable collaborations.

A GALEX-BASED SEARCH FOR THE SPARSE YOUNG STELLAR POPULATION IN THE TAURUS-AURIGAE STAR FORMING REGION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gómez de Castro, Ana I.; Lopez-Santiago, Javier; López-Martínez, Fatima

2015-02-01

In this work, we identify 63 bona fide new candidates to T Tauri stars (TTSs) in the Taurus-Auriga region, using its ultraviolet excess as our baseline. The initial data set was defined from the GALEX all sky survey (AIS). The GALEX satellite obtained images in the near-ultraviolet (NUV) and far-ultraviolet (FUV) bands where TTSs show a prominent excess compared with main-sequence or giants stars. GALEX AIS surveyed the Taurus-Auriga molecular complex, as well as a fraction of the California Nebula and the Perseus complex; bright sources and dark clouds were avoided. The properties of TTSs in the ultraviolet (GALEX), opticalmore » (UCAC4), and infrared (2MASS) have been defined using the TTSs observed with the International Ultraviolet Explorer reference sample. The candidates were identified by means of a mixed ultraviolet-optical-infrared excess set of colors; we found that the FUV-NUV versus J–K color-color diagram is ideally suited for this purpose. From an initial sample of 163,313 bona fide NUV sources, a final list of 63 new candidates to TTSs in the region was produced. The search procedure has been validated by its ability to detect all known TTSs in the area surveyed: 31 TTSs. Also, we show that the weak-lined TTSs are located in a well-defined stripe in the FUV-NUV versus J–K diagram. Moreover, in this work, we provide a list of TTSs photometric standards for future GALEX-based studies of the young stellar population in star forming regions.« less

J-SSOD 4 Mission

NASA Image and Video Library

2015-09-17

ISS045E014236 (09/17/2015) – A Japanese Small Satellite is deployed from outside the Japanese Experiment Module on Sept. 17, 2015. Two satellites were sent into Earth orbit by the Small Satellite Orbital Deployer. The first satellite is designed to observe the Ultraviolet (UV) spectrum during the Orionid meteor shower in October. The second satellite, sponsored by the University of Brasilia and the Brazilian government, focuses on meteorological data collection.

Physical Conditions in the Ultraviolet Absorbers of IRAS F22456-5125

NASA Astrophysics Data System (ADS)

Dunn, Jay P.; Crenshaw, D. Michael; Kraemer, S. B.; Trippe, M. L.

2010-04-01

We present the ultraviolet (UV) and X-ray spectra observed with the Far Ultraviolet Spectroscopic Explorer (FUSE) and the XMM-Newton satellite, respectively, of the low-z Seyfert 1 galaxy IRAS F22456 - 5125. This object shows absorption from five distinct, narrow kinematic components that span a significant range in velocity (~0 to -700 km s-1) and ionization (Lyman series, C III, N III, and O VI). We also show that three of the five kinematic components in these lines appear to be saturated in Lyβ λ1026 and that all five components show evidence of saturation in the O VI doublet lines λλ1032, 1038. Further, all five components show evidence for partial covering due to the absorption seen in the O VI doublet. This object is peculiar because it shows no evidence for corresponding X-ray absorption to the UV absorption in the X-ray spectrum, which violates the 1:1 correlation known for low-z active galactic nuclei (AGNs). We perform photoionization modeling of the UV absorption lines and predict that the O VII column density should be small, which would produce little to no absorption in agreement with the X-ray observation. We also examine the UV variability of the continuum flux for this object (an increase of a factor of 6). As the absorption components lack variability, we find a lower limit of ~20 kpc for the distance for the absorbers from the central AGN. Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by the Johns Hopkins University under NASA contract NAS5-32985.

Validation of Special Sensor Ultraviolet Limb Imager (SSULI) Ionospheric Tomography using ALTAIR Incoherent Scatter Radar Measurements

NASA Astrophysics Data System (ADS)

Dymond, K.; Nicholas, A. C.; Budzien, S. A.; Stephan, A. W.; Coker, C.; Hei, M. A.; Groves, K. M.

2015-12-01

The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors flying on the Defense Meteorological Satellite Program (DMSP) satellites. The SSULIs observe the 80-170 nanometer wavelength range covering emissions at 91 and 136 nm, which are produced by radiative recombination of the ionosphere. We invert these emissions tomographically using newly developed algorithms that include optical depth effects due to pure absorption and resonant scattering. We present the details of our approach including how the optimal altitude and along-track sampling were determined and the newly developed approach we are using for regularizing the SSULI tomographic inversions. Finally, we conclude with validations of the SSULI inversions against ALTAIR incoherent scatter radar measurements and demonstrate excellent agreement between the measurements.

KSC-99pp0700

NASA Image and Video Library

1999-06-17

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers begin removing the lower sections of the canister surrounding NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket

KSC-99pp0699

NASA Image and Video Library

1999-06-17

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers oversee the removal of the canister from the top of NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket

KSC-99pp0698

NASA Image and Video Library

1999-06-17

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers begin to remove the canister around the top of the NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket

KSC-99pp0703

NASA Image and Video Library

1999-06-17

At Launch Pad 17A, Cape Canaveral Air Station (CCAS), workers look over NASA's Far Ultraviolet Spectroscopic Explorer (FUSE) satellite after sections of the canister have been removed. FUSE is scheduled to be launched from CCAS June 23 aboard a Boeing Delta II rocket. FUSE is designed to scour the cosmos for the fossil record of the origins of the universe hydrogen and deuterium. Scientists will use FUSE to study hydrogen and deuterium to unlock the secrets of how the primordial chemical elements of which all stars, planets and life evolved, were created and distributed since the birth of the universe

Instrumentation development for the EUVE. [Extreme Ultraviolet Explorer Satellite

NASA Technical Reports Server (NTRS)

Finley, D.

1980-01-01

The prototype mirror was successfully replated with a thick layer of nickel and diamond turned again. Optimization of the sensitivity of the instruments was studied with emphasis on the filter material, and on the available telemetry. The JHU Preliminary Project Definition Document was critically analyzed. Further studies of the electron cloud distribution produced by a channel plate were performed, and a wedge and strip anode with 17 quartets per inch was shown to image with better than 0.5% linearity. Half the microchannel plates being used in the lifetest completed initial processing and are in the lifetest vacuum chamber.

Observations of interstellar hydrogen and deuterium toward Alpha Centauri A

NASA Technical Reports Server (NTRS)

Landsman, W. B.; Henry, R. C.; Moos, H. W.; Linsky, J. L.

1984-01-01

A composite profile is presented of the Ly-alpha emission line of Alpha Cen A, obtained from 10 individual spectra with the high-resolution spectrograph aboard the International Ultraviolet Explorer (IUE) satellite. There is excellent overall agreement with two previous Copernicus observations. Interstellar deuterium is detected, and a lower limit is set on the deuterium to hydrogen ratio of nDI/nHI greater than 8 x 10 to the -6th. In addition, the deuterium bulk velocity appears blueshifted by 8 + or - 2 km/s with respect to interstellar hydrogen, suggesting a nonuniform medium along the line of sight.

Goddard Laser for Absolute Measurement of Radiance for Instrument Calibration in the Ultraviolet to Short Wave Infrared

NASA Technical Reports Server (NTRS)

McAndrew, Brendan; McCorkel, Joel; Shuman, Timothy; Zukowski, Barbara; Traore, Aboubakar; Rodriguez, Michael; Brown, Steven; Woodward, John

2018-01-01

A description of the Goddard Laser for Absolute Calibration of Radiance, a tunable, narrow linewidth spectroradiometric calibration tool, and results from calibration of an earth science satellite instrument from ultraviolet to short wave infrared wavelengths.

Weighing the Low-Redshift Lyman-alpha Forest

NASA Technical Reports Server (NTRS)

Shull, Mike

2005-01-01

In 2003-2004, our FUSE research group prepared several major surveys of the amount of baryonic matter in the intergalactic medium (IGM), using the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. These surveys include measurements of the Lyman-alpha absorption line of neutral hydrogen (H I), the far-ultraviolet (1032,1038 Angstrom) doublet of highly ionized oxygen ( O VI), the higher Lyman-series lines (Ly-beta, Ly-gamma, etc) of H I, and the 977 Angstrom line of c III. As an overview, our FUSE spectroscopic studies, taken together with data from the Hubble Space Telescope, show that approximately 30% of the normal matter is contained in intergalactic hydrogen gas clouds (the Lyman-alpha forest). Another 5-10% resides in hotter gas at temperatures of 10(exp 5) to 10(exp 6) K, visible in 0 VI and C III absorption. Along with the matter attributed to galaxies, we have now accounted for approximately HALF of all the baryonic matter in the universe. Where is the other half? That matter my exist in even hotter gas, invisible through the ultraviolet absorption lines, but perhaps detectable through X-ray absorption lines of more highly ionized oxygen and neon.

Mass loss in the interacting semi-detached binary delta librae

NASA Technical Reports Server (NTRS)

Mccluskey, George E., Jr.; Mccluskey, Carolina P. S.; Kondo, Yoji

1995-01-01

The interacting Algol-type binary Delta Librae (AOV + G: V) has been observed with the International Ultraviolet Explorer (IUE) satellite. More than fifty high resolution spectra in the far-ultraviolet and mid-ultraviolet spectrum have been analyzed in order to model the mass flow in the Delta Librae system. The resonance lines of Si IV and C IV are present in absorption and vary in strength both secularly and with phase. The radial velocities of the Si IV and C IV absorption lines generally follow the orbital motion of the primary star but deviate by typically a few tens of kilometers per second in the direction of the observer. The presence of Si IV and C IV features indicates the existence of a region considerably hotter than the normal AOV photosphere and, since these lines are present at all phases, this region must be fairly extensive. These results are interpreted in terms of a 'pseudo-photosphere' around the equatorial region of the AOV star, created by matter being accreted from the G-type companion. The widths of the Si IV and C IV absorption features imply that some of the matter lost by the G-star leaves the system entirely.

Two-phase ultraviolet spectrophotometry of the pulsating white dwarf ZZ Piscium

NASA Technical Reports Server (NTRS)

Bond, H. E.; Kemper, E.; Grauer, A. D.; Holm, A. V.; Panek, R. J.; Schiffer, F. H., III

1985-01-01

Spectra of the pulsating white dwarf ZZ Psc (= G29-38) were obtained using the International Ultraviolet Explorer. By using a multiple-exposure technique in conjunction with simultaneous ground-based exposure-metering photometry, it was possible to obtain mean on-pulse and off-pulse spectra in the 1950-1310 A wavelength range. The ratio of the time-averaged on-pulse to off-pulse spectra is best fitted by a temperature variation that is in phase with the optical light variation. This result is consistent with the hypothesis that the observed variation is due to a high-order nonradial pulsation. Conventional ultraviolet spectra of ZZ Psc showed broad absorption features at 1390 and 1600 A. These features are also found in the spectra of the cool DA-type white dwarfs G226-29 and G67-23, and appear to increase in strength with decreasing temperature. A possible explanation for the 1600 A feature is absorption by the satellite band of resonance-broadened hydrogen Ly-alpha. Such absorption would also help explain a discrepancy between the observed pulsation amplitude shortward of 1650 A and the predicted amplitudes based on model atmospheres.

Ultraviolet spectroscopy of V Sagittae in high, intermediate and low states from HST and IUE satellites

NASA Astrophysics Data System (ADS)

Sanad, M. R.

2015-11-01

We present the first phase resolved ultraviolet spectroscopic study of V Sge in high, intermediate and low states observed with the Hubble Space Telescope High Resolution Spectrograph (HST HRS) and International Ultraviolet Explorer (IUE) during the period 1978-1996 to diagnose the ultraviolet fluxes of C IV 1550 Å and He II 1640 Å emission lines originating in the accretion disk during different orbital phases. Different spectra showing the variations in line fluxes at different orbital phases are presented. The reddening of V Sge is determined from the 2200 Å feature. We concentrated on calculating the line fluxes of C IV & He II emission lines. From HST and IUE data, we derived an accretion luminosity and an accretion rate for V Sge. The average temperature of the outer rim of the accretion disk {˜}10000 K. Our results show that there are variations in line fluxes, accretion luminosities and accretion rates with time for V Sge. These variations are attributed to the variations of both density and temperature as a result of a changing rate of mass transfer from the secondary star to the white dwarf. These results from the HST and IUE observations are consistent with the binary model consisting of a white dwarf, a disk around the white dwarf, and a lobe-filling main-sequence companion (Hachisu & Kato, Astrophys. J. 598:527H, 2003).

An intelligent user interface for browsing satellite data catalogs

NASA Technical Reports Server (NTRS)

Cromp, Robert F.; Crook, Sharon

1989-01-01

A large scale domain-independent spatial data management expert system that serves as a front-end to databases containing spatial data is described. This system is unique for two reasons. First, it uses spatial search techniques to generate a list of all the primary keys that fall within a user's spatial constraints prior to invoking the database management system, thus substantially decreasing the amount of time required to answer a user's query. Second, a domain-independent query expert system uses a domain-specific rule base to preprocess the user's English query, effectively mapping a broad class of queries into a smaller subset that can be handled by a commercial natural language processing system. The methods used by the spatial search module and the query expert system are explained, and the system architecture for the spatial data management expert system is described. The system is applied to data from the International Ultraviolet Explorer (IUE) satellite, and results are given.

Observations and Operational Products from the Special Sensor Ultraviolet Limb Imager (SSULI)

NASA Astrophysics Data System (ADS)

Dandenault, Patrick; Nicholas, Andrew C.; Coker, Clayton; Budzien, Scott A.; Chua, Damien H.; Finne, Ted T.; Metzler, Christopher A.; Dymond, Kenneth F.

The Naval Research Laboratory (NRL) has developed five ultraviolet remote sensing instru-ments for the Air Force Defense Meteorological Satellite Program (DMSP). These instruments known as SSULI (Special Sensor Ultraviolet Limb Imager) are on the DMSP block of 5D3 satellites, which first launched in 2003. The DMSP satellites are launched in a near-polar, sun-synchronous orbit at an altitude of approximately 830 km. SSULI measures vertical profiles of the natural airglow radiation from atoms, molecules and ions in the upper atmosphere and ionosphere by viewing the earth's limb at a tangent altitude of approximately 50 km to 750 km. Limb observations are made from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nm to 170 nm, with 1.8 nm resolution. An extensive operational data processing system, the SSULI Ground Data Analysis Software (GDAS), has been developed to generate environmental data products from SSULI spectral data in near-real time for use at the Air Force Weather Agency (AFWA). The operational software uses advanced science algorithms developed at NRL and was designed to calibrate data from USAF Raw Sensor Data Records (RSDR) and generate Environmental Data Records (EDRs). Data products from SSULI observations include vertical profiles of electron (Ne) densities, N2, O2, O, O+, Temperature and also vertical Total Electron Content (TEC). On October 18, 2009, the third SSULI sensor launched from Vandenberg Air Force Base, aboard the DMSP F18 spacecraft. An overview of the SSULI operational program and the status of the F18 sensor will be discussed.

Comparison of spectral ultraviolet irradiance measured from satellite and ground-based instrument at Nakhon Pathom province

NASA Astrophysics Data System (ADS)

Sriwongsa, J.; Buntoung, S.

2017-09-01

In this study, comparisons of spectral ultraviolet irradiance at 305, 310, 324 and 380 nm at the overpass time retrieved from OMI/AURA satellite with that from ground-based measurements were performed at Nakhon Pathom (13.82°N,100.04°E), Thailand. The analyzed data period comprised from 1 January 2010 to 31 December 2015. The comparison results clearly showed the overestimation of satellite data with root mean square difference (RMSD) between 22.9 and 48.9%, and mean bias difference (MBD) between 5.3 and 39.8% for all sky conditions, and reduced to 10.6-40.5% and 0.18-34.9% for clear sky conditions. Further results showed that the differences between the two datasets depend on atmospheric aerosol loads and clouds.

Nickel cadmium battery operations and performance

NASA Technical Reports Server (NTRS)

Rao, Gopalakrishna; Prettyman-Lukoschek, Jill; Calvin, Richard; Berry, Thomas; Bote, Robert; Toft, Mark

1994-01-01

The Earth Radiation Budget Satellite (ERBS), Compton Gamma Ray Observatory (CGRO), Upper Atmosphere Research Satellite (UARS), and Extreme Ultraviolet Explorer (EUVE) spacecraft are operated from NASA's Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. On-board power subsystems for each satellite employ NASA Standard 50 Ampere-hour (Ah) nickel-cadmium batteries in a parallel configuration. To date, these batteries have exhibited degradation over periods from several months (anomalous behavior, UARS and CGRO (MPS-1); to little if any, EUVE) to several years (old age, normal behavior, ERBS). Since the onset of degraded performance, each mission's Flight Operations Team (FOT), under the direction of their cognizant GSFC Project Personnel and Space Power Application Branch's Engineers has closely monitored the battery performance and implemented several charge control schemes in an effort to extend battery life. Various software and hardware solutions have been developed to minimize battery overcharge. Each of the four sections of this paper covers a brief overview of each mission's operational battery management and its associated spacecraft battery performance. Also included are new operational procedures developed on-orbit that may be of special interest to future mission definition and development.

UV Signatures of Ices: Moons in the Solar System

NASA Astrophysics Data System (ADS)

Hendrix, A. R.; Hansen, C. J.; Retherford, K. D.; Vilas, F.

2017-12-01

Using Earth-orbiting telescopes such as the International Ultraviolet Explorer and the Hubble Space Telescope, significant advances have been made in the area of ultraviolet observations of solar system objects. More in-depth studies have been made using interplanetary probes such as Galileo, Cassini and Lunar Reconnaissance Orbiter (LRO). While the UV spectral range has traditionally been used to study atmospheric and auroral processes, there is much to be learned by examining solid surfaces in the UV, including surface composition, weathering processes and effects, and the generation of thin atmospheres. Here we focus on moons in the solar system, including Earth's moon and the Saturnian satellites. The diagnostic UV signature of H2O is used to study ice in the lunar polar regions as well as hydration at lower latitudes, in observations from LRO LAMP. The water ice signature is nearly ubiquitous in the Saturn system; Cassini UVIS datasets are used to study grain sizes, exogenic processes/effects and non-ice species.

The CI pressure shift and gravitational redshift of the cool DBQA5 white dwarf LDS678A

NASA Technical Reports Server (NTRS)

Sion, E. M.; Vauclair, G.; Oswalt, T. D.; Hammond, G.; Liebert, J.; Koester, D.; Wegner, G.; Marcum, P.

1990-01-01

A high resolution ultraviolet spectrum of the helium rich degenerate LDS 678A, obtained with the International Ultraviolet Explorer (IUE) satellite is presented. LDS 678A is the coolest metallic line generate (DQ or DZ) yet observed with the IUE scale. These observations provide a detailed line profile of the strong C I 2479 absorption line with equivalent width (W sub 2479 = 2.35 plus or minus 0.06 angstroms) from which theoretical line profile fits yield a C abundance (log C/He = 6.4). The presence of carbon in a helium rich atmosphere lends credence to the notion that LDS 678A is a transitional case between the DB white dwarfs with nearly pure helium atmospheres and the helium rich DQ white dwarfs which exhibit carbon bands. Corrected for an inferred pressure shift for the C I line, a gravitational redshift is deduced from which a most probable mass of 0.55 solar mass is derived.

The composite nature of the peculiar star HR 6560 (HD 159870)

NASA Technical Reports Server (NTRS)

Wegner, Gary; Cowley, Charles R.

1992-01-01

Ground-based high-dispersion photographic spectra and ultraviolet spectra obtained with the IUE satellite are described and employed to determine the nature of the peculiar star HR 6560 (HD 159870). Previously this object had been described as both a composite system and as a strong Fm star. The UBVRI, Stromgren, and ultraviolet colors of HR 6560 are compared with objects classified composite from the Bright Star Catalogue and normal dwarfs and giants. The colors of HR 6560 are not unusual for a composite and are consistent with a late-A dwarf, combined with a late-G or early-K giant. The ultraviolet satellite clearly shows the presence of an A component, but its precise spectral type is difficult to assign. The IUE and TD-1 data suggest that the ultraviolet is dominated by light from an A5 V secondary and the visual from a GO III primary. This does not agree well with the most plausible model that fits the visual photometry. The peculiar nature of HR 6560's spectrum is most likely due to its composite nature.

The wind of EG Andromedae is not dust driven

NASA Technical Reports Server (NTRS)

Van Buren, Dave; Dgani, Ruth; Noriega-Crespo, Alberto

1994-01-01

The symbiotic star EG Andromedae has recently been the subject of several studies investigating its wind properties. Late-type giants are usually considered to have winds driven by radiation pressure on dust. Indeed, the derived wind velocity for EG Andromedae is consistent with this model. We point out here that there is no appreciable dust opacity in the wind of EG Andromedae using constraints on extinction limits from International Ultraviolet Explorer (IUE) and far infrared fluxes from Infrared Astronomy Satellite (IRAS). An alternate mechanism must operate in this star. We suggest that the wind can be driven by radiation pressure on molecular lines.

ROSAT: An international mission exploring the high energy universe

NASA Technical Reports Server (NTRS)

1991-01-01

ROSAT was designed specifically to detect high energy radiation, by using its telescopes to study x ray and ultraviolet emissions, regions of the electromagnetic spectrum that cannot be seen and that cannot penetrate the Earth's atmosphere. ROSAT is an international astronomical observatory project. ROSAT's science mission is divided into two phases. With its in-orbit checkout period complete, ROSAT has begun phase one of its mission, an all sky survey to map the heavens. When the 6 month mapping survey is complete, the satellite will begin phase two and be pointed at selected objects, studying individual targets, for the remainder of its mission.

Remote Determination of Auroral Energy Characteristics During Substorm Activity

NASA Technical Reports Server (NTRS)

Germany, G. A.; Parks, G. K.; Brittnacher, M. J.; Cumnock, J.; Lummerzheim, D.; Spann, J. F., Jr.

1997-01-01

Ultraviolet auroral images from the Ultraviolet Imager onboard the POLAR satellite can be used as quantitative remote diagnostics of the auroral regions, yielding estimates of incident energy characteristics, compositional changes, and other higher order data products. In particular, images of long and short wavelength N2 Lyman-Birge-Hopfield (LBH) emissions can be modeled to obtain functions of energy flux and average energy that are basically insensitive to changes in seasonal and solar activity changes. This technique is used in this study to estimate incident electron energy flux and average energy during substorm activity occurring on May 19, 1996. This event was simultaneously observed by WIND, GEOTAIL, INTERBALL, DMSP and NOAA spacecraft as well as by POLAR. Here incident energy estimates derived from Ultraviolet Imager (UVI) are compared with in situ measurements of the same parameters from an overflight by the DMSP F12 satellite coincident with the UVI image times.

A DETAILED FAR-ULTRAVIOLET SPECTRAL ATLAS OF MAIN-SEQUENCE B STARS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Myron A.

2010-02-01

We have constructed a detailed spectral atlas covering the wavelength region 930-1225 A for 10 sharp-lined B0-B9 stars near the main sequence. Most of the spectra we assembled are from the archives of the Far Ultraviolet Spectroscopic Explorer satellite, but for nine stars, wavelength coverage above 1188 A was taken from high-resolution International Ultraviolet Explorer or echelle Hubble Space Telescope/Space Telescope Imaging Spectrograph spectra. To represent the tenth star at type B0.2 V, we used the Copernicus atlas of {tau} Sco. We made extensive line identifications in the region 949-1225 A of all atomic features having published oscillator strengths atmore » types B0, B2, and B8. These are provided as a supplementary data product-hence the term detailed atlas. Our list of found features totals 2288, 1612, and 2469 lines, respectively. We were able to identify 92%, 98%, and 98% of these features with known atomic transitions with varying degrees of certainty in these spectra. The remaining lines do not have published oscillator strengths. Photospheric lines account for 94%, 87%, and 91%, respectively, of all our identifications, with the remainder being due to interstellar (usually molecular H{sub 2}) lines. We also discuss the numbers of lines with respect to the distributions of various ions for these three most studied spectral subtypes. A table is also given of 162 least blended lines that can be used as possible diagnostics of physical conditions in B star atmospheres.« less

The Extreme Ultraviolet spectrometer on bard the Hisaki satellite

NASA Astrophysics Data System (ADS)

Yoshioka, K.; Murakami, G.; Yamazaki, A.; Tsuchiya, F.; Kagitani, M.; Kimura, T.; Yoshikawa, I.

2017-12-01

The extreme ultraviolet spectroscope EXCEED (EXtrem ultraviolet spetrosCope for ExosphEric Dynamics) on board the Hisaki satellite was launched in September 2013 from the Uchinoura space center, Japan. It is orbiting around the Earth with an orbital altitude of around 950-1150 km. This satellite is dedicated to and optimized for observing the atmosphere and magnetosphere of terrestrial planets such as Mercury, Venus, Mars, as well as Jupiter. The instrument consists of an off axis parabolic entrance mirror, switchable slits with multiple filters and shapes, a toroidal grating, and a photon counting detector, together with a field of view guiding camera. The design goal is to achieve a large effective area but with high spatial and spectral resolution. Based on the after-launch calibration, the spectral resolution of EXCEED is found to be 0.3-0.5 nm FWHM (Full Width at Half Maximum) over the entire spectral band, and the spatial resolution is around 17". The evaluated effective area is larger than 1cm2. In this presentation, the basic concept of the instrument design and the observation technique are introduced. The current status of the spacecraft and its future observation plan are also shown.

KSC-97PC1032

NASA Image and Video Library

1997-07-10

A payload canister in the Payload Changeout Room (PCR) at Launch Pad 39A holds the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission (center), as well as the Technology Applications and Science-1 (TAS-1) (top) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) (bottom) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

KSC-97PC1008

NASA Image and Video Library

1997-07-07

The Technology Applications and Science-1 (TAS-1) payload for the STS-85 mission rests in a payload canister in the Space Station Processing Facility prior to its trip out to Launch Pad 39A for installation into the payload bay of the Space Shuttle Orbiter Discovery. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. Other STS-85 payloads include the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2). The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The International Extreme Ultraviolet Hitchhiker-2 (IEH-2) will also be in the payload bay. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

KSC-97PC1033

NASA Image and Video Library

1997-07-10

A payload canister in the Payload Changeout Room (PCR) at Launch Pad 39A holds the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission (center), as well as the Technology Applications and Science-1 (TAS-1) (top) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) (bottom) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

Observations of the Ultraviolet Spectra of Helium (DB) White Dwarfs and a Study of the Ultraviolet Spectra of White Dwarfs Containing Carbon

NASA Technical Reports Server (NTRS)

Wegner, G. A.

1984-01-01

Strong ultraviolet carbon lines were detected in the spectrum of the southern DC white dwarf BPM 11668. Observations of a number of hotter DB white dwarfs with IUE show no evidence of carbon features. Two additional DA white dwarfs were observed that have the strong unidentified absorption near 1400 A which now seems to be identified with another lower temperature feature as satellite lines to Lyman alpha radiation.

Documentation for the machine-readable version of the ANS Ultraviolet Photometry Catalogue of Point Sources (Wesselius et al 1982)

NASA Technical Reports Server (NTRS)

Warren, W. H., Jr.

1984-01-01

The machine-readable version of the Astronomical Netherlands Satellite ultraviolet photometry catalog is described in detail, with a byte-by-byte format description and characteristics of the data file given. The catalog is a compilation of ultraviolet photometry in five bands, within the wavelength range 155 nm to 330 nm, for 3573 mostly stellar objects. Additional cross reference data (object identification, UBV photometry and MK spectral types) are included in the catalog.

Solar Imaging UV/EUV Spectrometers Using TVLS Gratings

NASA Technical Reports Server (NTRS)

Thomas, Roger J.

2003-01-01

It is a particular challenge to develop a stigmatic spectrograph for UV, EUV wavelengths since the very low normal-incidence reflectance of standard materials most often requires that the design be restricted to a single optical element which must simultaneously provide both reimaging and spectral dispersion. This problem has been solved in the past by the use of toroidal gratings with uniform line-spaced rulings (TULS). A number of solar extreme ultraviolet (EUV) spectrometers have been based on such designs, including SOHO/CDS, Solar-B/EIS, and the sounding rockets Solar Extreme ultraviolet Research Telescope and Spectrograph (SERTS) and Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS). More recently, Kita, Harada, and collaborators have developed the theory of spherical gratings with varied line-space rulings (SVLS) operated at unity magnification, which have been flown on several astronomical satellite missions. We now combine these ideas into a spectrometer concept that puts varied-line space rulings onto toroidal gratings. Such TVLS designs are found to provide excellent imaging even at very large spectrograph magnifications and beam-speeds, permitting extremely high-quality performance in remarkably compact instrument packages. Optical characteristics of three new solar spectrometers based on this concept are described: SUMI and RAISE, two sounding rocket payloads, and NEXUS, currently being proposed as a Small-Explorer (SMEX) mission.

Remote sensing of the magnetic moment of uranus: predictions for voyager.

PubMed

Hill, T W; Dessler, A J

1985-03-22

Power is supplied to a planet's magnetosphere from the kinetic energy of planetary spin and the energy flux of the impinging solar wind. A fraction of this power is available to drive numerous observable phenomena, such as polar auroras and planetary radio emissions. In this report our present understanding of these power transfer mechanisms is applied to Uranus to make specific predictions of the detectability of radio and auroral emissions by the planetary radio astronomy (PRA) and ultraviolet spectrometer (UVS) instruments aboard the Voyager spacecraft before its encounter with Uranus at the end of January 1986. The power available for these two phenomena is (among other factors) a function of the magnetic moment of Uranus. The date of earliest detectability also depends on whether the predominant power source for the magnetosphere is planetary spin or solar wind. The magnetic moment of Uranus is derived for each power source as a function of the date of first detection of radio emissions by the PRA instrument or auroral emissions by the UVS instrument. If we accept the interpretation of ultraviolet observations now available from the Earth-orbiting International Ultraviolet Explorer satellite, Uranus has a surface magnetic field of at least 0.6 gauss, and more probably several gauss, making it the largest or second-largest planetary magnetic field in the solar system.

Artist Concept of Galaxy Evolution Explorer

NASA Image and Video Library

2002-12-21

The Galaxy Evolution Explorer was launched on April 28, 2003. Its mission is to study the shape, brightness, size and distance of galaxies across 10 billion years of cosmic history. The 50-centimeter-diameter (19.7-inch) telescope onboard the Galaxy Evolution Explorer sweeps the skies in search of ultraviolet-light sources. Ultraviolet is light from the higher end of the electromagnetic spectrum, just above visible light in frequency, but below X-rays and gamma rays. While a small amount of ultraviolet penetrates Earth's atmosphere, causing sunburn, the Galaxy Evolution Explorer observes those ultraviolet frequencies that can only be seen from space. http://photojournal.jpl.nasa.gov/catalog/PIA04234

The Link Between UV Extinction and Infrared Cirrus

NASA Technical Reports Server (NTRS)

Hackwell, John A.; Hecht, James; Canterna, Ronald

1997-01-01

Low resolution spectra from the International Ultraviolet Explorer satellite were used to derive ultraviolet extinction curves for stars in four clusters away from the galactic plane. The extinction in three of the clusters is very similar to the general interstellar curve defined by Seaton. Stars in the fourth region, near the Rho Ophiuci dark cloud, have extinction curves that are characterized by a small "linear" term component. The star BD +36 deg 781 is unique amongst the 20 stars observed in that it shows evidence for extinction by diamond grains near 1700 angstroms. We used data from the final release of the IRAS Sky Survey Atlas (ISSA) to determine the 60 micron to 100 micron intensity ratio for the infrared cirrus. The ISSA data, which have been corrected for zodiacal light, gave intensity ratios that are more robust and self-consistent than for other data sets that we used. When the infrared and ultraviolet data are combined, we see a general trend for low values of the ultraviolet "linear term" (al) to correlate with high values of 60 micron/100 micron ratio. This implies that, in regions where the average dust temperature is hotter (high 60 micron/100 micron ratio), there is a relative absence of the small silicate grains that are responsible for the ultraviolet linear term. However, the new data do not bear out our earlier contention that the 60 micron and 100 micron emissions are poorly correlated spatially in regions where the 60 micron/100 micron ratio is low. Only NGC 1647 shows this result. It may be that the different dust types are particularly poorly mixed in this area.

Modeling UV-B Effects on Primary Production Throughout the Southern Ocean Using Multi-Sensor Satellite Data

NASA Technical Reports Server (NTRS)

Lubin, Dan

2001-01-01

This study has used a combination of ocean color, backscattered ultraviolet, and passive microwave satellite data to investigate the impact of the springtime Antarctic ozone depletion on the base of the Antarctic marine food web - primary production by phytoplankton. Spectral ultraviolet (UV) radiation fields derived from the satellite data are propagated into the water column where they force physiologically-based numerical models of phytoplankton growth. This large-scale study has been divided into two components: (1) the use of Total Ozone Mapping Spectrometer (TOMS) and Special Sensor Microwave Imager (SSM/I) data in conjunction with radiative transfer theory to derive the surface spectral UV irradiance throughout the Southern Ocean; and (2) the merging of these UV irradiances with the climatology of chlorophyll derived from SeaWiFS data to specify the input data for the physiological models.

Interstellar molecules. [detection from Copernicus satellite UV absorption data

NASA Technical Reports Server (NTRS)

Drake, J. F.

1974-01-01

The Princeton equipment on the Copernicus satellite provides the means to study interstellar molecules between the satellite and stars from 20 to 1000 pc distant. The study is limited to stars relatively unobscured by dust which strongly attenuates the ultraviolet continuum flux used as a source to probe the interstellar medium. Of the 14 molecules searched for only three have been detected including molecular hydrogen, molecular HD, and carbon monoxide.

The Copernicus ultraviolet spectral atlas of Sirius

NASA Technical Reports Server (NTRS)

Rogerson, John B., Jr.

1987-01-01

A near-ultraviolet spectral atlas for the A1 V star Alpha CMa (Sirius) has been prepared from data taken by the Princeton spectrometer aboard the Copernicus satellite. The spectral region from 1649 to 3170 A has been scanned with a resolution of 0.1 A. The atlas is presented in graphs, and line identifications for the absorption features have been tabulated.

The Copernicus ultraviolet spectral atlas Tau Scorpii

NASA Technical Reports Server (NTRS)

Rogerson, J. B., Jr.; Upson, W. L., II

1977-01-01

An ultraviolet spectral atlas was presented for the B0 V star, Tau Scorpii. It was scanned from 949 to 1560 A by the Princeton spectrometer aboard the Copernicus satellite. From 949 to 1420 A the observations have a nominal resolution of 0.05 A. At the longer wavelengths, the resolution was 0.1 A. The atlas was presented in both tables and graphs.

Long-term calibration monitoring of Spectralon diffusers BRDF in the air-ultraviolet.

PubMed

Georgiev, Georgi T; Butler, James J

2007-11-10

Long-term calibration monitoring of the bidirectional reflectance distribution function (BRDF) of Spectralon diffusers in the air-ultraviolet is presented. Four Spectralon diffusers were monitored in this study. Three of the diffusers, designated as H1, H2, and H3, were used in the prelaunch radiance calibration of the Solar Backscatter Ultraviolet/2 (SBUV/2) satellite instruments on National Oceanic and Atmospheric Administration (NOAA) 14 and 16. A fourth diffuser, designated as the 400 diffuser, was used in the prelaunch calibration of the Ozone Mapping and Profiler Suite (OMPS) instrument scheduled for initial flight in 2009 on the National Polar Orbiting Environmental Satellite System Preparatory Project. The BRDF data of this study were obtained between 1994 and 2005 using the scatterometer located in the National Aeronautics and Space Administration Goddard Space Flight Center Diffuser Calibration Laboratory. The diffusers were measured at 13 wavelengths between 230 and 425 nm at the incident and scatter angles used in the prelaunch calibrations of SBUV/2 and OMPS. Spectral features in the BRDF of Spectralon are also discussed. The comparison shows how the air-ultraviolet BRDF of these Spectralon samples changed over time under clean room deployment conditions.

Investigation of the effect of atmospheric dust on the determination of total ozone from the earth's ultraviolet reflectivity measurements

NASA Technical Reports Server (NTRS)

Dave, J. V.

1977-01-01

Results are presented on the effect of atmospheric aerosols on the value of total ozone, in an atmospheric column of the terrestrial atmosphere, estimated from the simulated measurements of the ultraviolet radiation back scattered by the earth atmosphere models. Simulated measurements were used in five (configuration of the BUV experiment of Nimbus-4 satellite), and in six (configuration of the TOMS section of the SBUV/TOMS experiment on Nimbus-G) narrow spectral regions in the ultraviolet part of the spectrum.

Dancing to the MUSSIC: Steps towards creating a Multisatellite Ultraviolet Solar Spectral Irradiance Composite

NASA Astrophysics Data System (ADS)

Snow, M. A.; Machol, J. L.; Richard, E. C.

2016-12-01

Solar spectral irradiance (SSI) has been measured since the beginning of the satellite era in 1978, but the observational record has many gaps in both wavelength and time. We describe our current effort in linking several such datasets ranging from the Extreme Ultraviolet to the Near Ultraviolet (0-400 nm). This wavelength range includes two important solar activity proxies, the Magnesium II core—to-wing ratio and the Lyman alpha irradiance, and special attention will be applied to these two wavelength intervals.

Spectrophotometry of planets, asteroids and satellites from the international ultraviolet explorer satellite

NASA Technical Reports Server (NTRS)

Tomasko, M. G.; Zellner, B.; Martinek, S.; Gehrels, T.

1981-01-01

A total of 14 8 hour I.U.E. observing sessions resulted in 39 spectra of 11 asteroids and 9 solar type stars as well as 57 spectra at various locations on the disk of Jupiter. The Jupiter observations include a total of 5 center to limb series of spectra at various latitudes and a North South series along the central meridian. In the range from 2000-3000 A, the planet shows a striking decrease in brightness at latitudes greater than about 30 degrees, and exhibits limb brightening at low latitudes and limb darkening at high latitudes. Preliminary results indicate that about 6 km-amagats of clean hydrogen are required above a haze of absorbing aerosols to reproduce the limb brightening observed at 2500 A in the equatorial regions. At higher latitudes, the aerosols extend to even higher levels of the atmosphere. Comparison of the Jovian data with detailed model calculations and the analyses of the asteroid spectra are still in progress with other support.

Searching for Radial Velocity Variations in eta Carinae

NASA Technical Reports Server (NTRS)

Iping, R. C.; Sonneborn, G.; Gull, T. R.; Ivarsson, S.; Nielsen, K.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1180 A) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite (see poster by Sonneborn et al.). Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. The N II 1084-86 emission feature indicates that the star may be nitrogen rich. The FUV continuum and the S IV 1073 P-Cygni wind line suggest that the effective temperature of eta Car B is at least 25,000 K. FUV spectra of eta Carinae were obtained with the FUSE satellite at 9 epochs between 2000 February and 2005 July. The data consists of 12 observations taken with the LWRS aperture (30x30 arcsec), three with the HIRS aperture (1.25x20 arcsec), and one MRDS aperture (4x20 arcsec). In this paper we discuss the analysis of these spectra to search for radial velocity variations associated with the 5.54-year binary orbit of Eta Car AB.

Accurate attitude determination of the LACE satellite

NASA Technical Reports Server (NTRS)

Miglin, M. F.; Campion, R. E.; Lemos, P. J.; Tran, T.

1993-01-01

The Low-power Atmospheric Compensation Experiment (LACE) satellite, launched in February 1990 by the Naval Research Laboratory, uses a magnetic damper on a gravity gradient boom and a momentum wheel with its axis perpendicular to the plane of the orbit to stabilize and maintain its attitude. Satellite attitude is determined using three types of sensors: a conical Earth scanner, a set of sun sensors, and a magnetometer. The Ultraviolet Plume Instrument (UVPI), on board LACE, consists of two intensified CCD cameras and a gimbal led pointing mirror. The primary purpose of the UVPI is to image rocket plumes from space in the ultraviolet and visible wavelengths. Secondary objectives include imaging stars, atmospheric phenomena, and ground targets. The problem facing the UVPI experimenters is that the sensitivity of the LACF satellite attitude sensors is not always adequate to correctly point the UVPI cameras. Our solution is to point the UVPI cameras at known targets and use the information thus gained to improve attitude measurements. This paper describes the three methods developed to determine improved attitude values using the UVPI for both real-time operations and post observation analysis.

Colliding stellar winds in the eclipsing Wolf-Rayet binary V444 Cygni

NASA Technical Reports Server (NTRS)

Brown, Douglas N.; Shore, Steven N.

1988-01-01

High resolution spectra of V444 Cygni have been obtained using the International Ultraviolet Explorer Satellite. These spectra span both eclipses and include one observation at third quadrature. Together with seven archival spectra, they provide reasonably complete phase coverage for the system. The variations in the P Cygni profiles of the He(II) and N(IV) lines, imply the existence of a low density region in the WR wind. This region occupies a relatively narrow range of orbital phase coinciding with the highest terminal velocities observed in C IV. These data are interpreted to be evidence of an interaction region separating the winds of the O-star and Wolf-Rayet star.

Chemistry of the thermosphere and ionosphere

NASA Technical Reports Server (NTRS)

Torr, D. G.; Torr, M. R.

1979-01-01

In the present paper, some of the most important features of the Atmosphere Explorer program, involving studies of the chemistry of the ionosphere and thermosphere, are reviewed. Solar flux and cross sections are tabulated, along with the revised reference spectrum F47113 as compared with the preliminary R74113. The principal results examined include some unexpected variations in the EUV flux and in the response of the thermosphere, revealed by extreme ultraviolet spectrophotometers; discrepancies between the measured and calculated electron flux; recent developments in the detection of nocturnal mid- and low-latitude sources of ionization; and the application of AE satellite data to the study of ionospheric and thermospheric processes, rate coefficients, and atomic and molecular processes.

Ultraviolet Spectroscopy of the Surfaces of the Inner Icy Saturnian Satellites

NASA Astrophysics Data System (ADS)

Hendrix, A. R.; Hansen, C. J.

2008-12-01

The Cassini mission has provided a unique opportunity to make high-resolution, multi-spectral measurements of Saturn's icy moons, to investigate their surface compositions, processes and evolution. Here we present results from the Ultraviolet Imaing Spectrograph (UVIS). This instrument allows for the first measurements of the icy satellites in the extreme ultraviolet (EUV) to far-ultraviolet (FUV) wavelength range. The icy satellites of the Saturn system exhibit a remarkable amount of variability: Dark, battered Phoebe orbiting at a distant 200 RS, black-and-white Iapetus, the wispy streaks of Dione, cratered Rhea and Mimas, bright Tethys and geologically active Enceladus. Phoebe, Iapetus and Hyperion all orbit largely outside Saturn's magnetosphere, while the inner icy satellites Mimas, Enceladus, Dione Tethys and Rhea all orbit within the magnetosphere. Furthermore, the inner icy satellites all orbit within the E-ring - so the extent of exogenic effects on these icy satellites is wide-ranging. We present an overview of UVIS results from Tethys, Dione, Mimas, Enceladus and Rhea, focusing on surface investigations. We expect that the UV signatures of these icy satellites are strongly influenced not only by their water ice composition, but by external effects and magnetospheric environments. We study the FUV reflectance spectra to learn about the surface composition, map out water ice grain size variations, investigate effects of coating by E-ring grains, examine disk-resolved and hemispheric compositional and brightness variations, and investigate the presence of radiation products. This is new work: FUV spectra of surfaces have not been well-studied in the past. Spectra of the inner icy moons have been used to better develop spectral models, to further understand existing lab data of water ice and to help with understanding instrument performance. Analysis is challenged by a lack of laboratory data in this wavelength region, but intriguing results are being found. We find that the FUV albedo is a critical tie- point to understand the composition of these moons -- important absorptions occur in the NUV-visible region. We present disk-integrated hemispherical reflectance spectra, and show that while Tethys and Dione exhibit strong UV leading-trailing differences, Mimas, Enceladus and Rhea do not. In the UV, Mimas is nearly as bright as Enceladus. Tethys is surprisingly dark in the UV. The visible-wavelength leading-trailing hemisphere albedo differences can be attributed to coating by E-ring grains; in the UV, a process appears to darken the trailing hemisphere of Tethys. We also investigate disk-resolved Enceladus spectra to understand spectral differences between the south polar tiger stripe region and elsewhere on the surface.

SSULI/SSUSI UV Tomographic Images of Large-Scale Plasma Structuring

NASA Astrophysics Data System (ADS)

Hei, M. A.; Budzien, S. A.; Dymond, K.; Paxton, L. J.; Schaefer, R. K.; Groves, K. M.

2015-12-01

We present a new technique that creates tomographic reconstructions of atmospheric ultraviolet emission based on data from the Special Sensor Ultraviolet Limb Imager (SSULI) and the Special Sensor Ultraviolet Spectrographic Imager (SSUSI), both flown on the Defense Meteorological Satellite Program (DMSP) Block 5D3 series satellites. Until now, the data from these two instruments have been used independently of each other. The new algorithm combines SSULI/SSUSI measurements of 135.6 nm emission using the tomographic technique; the resultant data product - whole-orbit reconstructions of atmospheric volume emission within the satellite orbital plane - is substantially improved over the original data sets. Tests using simulated atmospheric emission verify that the algorithm performs well in a variety of situations, including daytime, nighttime, and even in the challenging terminator regions. A comparison with ALTAIR radar data validates that the volume emission reconstructions can be inverted to yield maps of electron density. The algorithm incorporates several innovative new features, including the use of both SSULI and SSUSI data to create tomographic reconstructions, the use of an inversion algorithm (Richardson-Lucy; RL) that explicitly accounts for the Poisson statistics inherent in optical measurements, and a pseudo-diffusion based regularization scheme implemented between iterations of the RL code. The algorithm also explicitly accounts for extinction due to absorption by molecular oxygen.

KSC-97PC1009

NASA Image and Video Library

1997-07-07

The International Extreme Ultraviolet Hitchhiker-2 (IEH-2) payload rests in a work stand in the Space Station Processing Facility prior to its trip out to Launch Pad 39A for installation into the payload bay of the Space Shuttle Orbiter Discovery for the STS-85 mission. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system. The Technology Applications and Science-1 (TAS-1) payload is another series of experiments that will be conducted during the 11-day mission in Discovery’s payload bay. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. Other STS-85 payloads include the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2). The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. The CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere

KSC-97PC1030

NASA Image and Video Library

1997-07-10

KENNEDY SPACE CENTER, Fla. -- The payload canister containing the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission is hoisted to the Payload Changeout Room (PCR) at Launch Pad 39A. Also in the canister are the Technology Applications and Science-1 (TAS-1) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

CRISTA-SPAS is placed in the PCR at LC 39A

NASA Technical Reports Server (NTRS)

1997-01-01

A payload canister in the Payload Changeout Room (PCR) at Launch Pad 39A holds the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission (center), as well as the Technology Applications and Science-1 (TAS-1) (top) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) (bottom) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth's middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth's atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth's topography and atmosphere, study the sun's energy, and test new thermal control devices, as well as several student- developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system.

UV observations of the cool DBQA5 white dwarf LDS 678A - Limits on the atmospheric composition, pressure shift, and gravitational redshift derived from C I 2479

NASA Technical Reports Server (NTRS)

Oswalt, Terry D.; Sion, Edward M.; Hammond, Gordon; Vauclair, Gerard; Liebert, James W.

1991-01-01

A high-resolution ultraviolet spectrum of the helium-rich degenerate LDS 678A, obtained with the International Ultraviolet Explorer (IUE) satellite, is presented. LDS 678A is the coolest metallic line degenerate (DQ or DZ) yet observed with the IUE echelle. These observations provide a detailed line profile of the strong C I 2479 absorption line and equivalent width W2479 = 2.35 + or - 0.06 A from which theoretical profile fits yield a carbon abundance of log C/He = (-6.7 + or- 0.2). The presence of carbon in a He-rich atmosphere lends credence to the notion that LDS 678A is a transitional case between the DB white dwarfs with nearly pure helium atmospheres and the helium-rich DQ white dwarfs which exhibit carbon bands. Corrected for an inferred pressure shift Vp = + 38 + or - 4 km/s for the C I 2479 line, a gravitational redshift of Vrs = + 26 + or - 13 km/s is deduced from which a most probable mass of 0.55 solar mass is derived.

Ultraviolet carbon lines in the spectrum of the white dwarf BPM 11668

NASA Technical Reports Server (NTRS)

Wegner, G.

1983-01-01

The southern hemisphere DC white dwarf BPM 11668 has been found to show strong ultraviolet lines of neutral carbon using observations from the IUE satellite. This star seems typical of the growing number of DC white dwarfs found to be of this type and appears to have a carbon abundance near C:He = 0.0001, with an effective temperature of 8500 K.

The DMSP Space Weather Sensors Data Archive Listing (1982-2013) and File Formats Descriptions

DTIC Science & Technology

2014-08-01

environment sensors including the auroral particle spectrometer (SSJ), the fluxgate magnetometer (SSM), the topside thermal plasma monitor (SSIES... Fluxgate Magnetometer (SSM) for the Defense Meteorological Satellite Program (DMSP) Block 5D-2, Flight 7, Instrument Papers, AFGL-TR-84-0225; ADA155229...Flux) SSM The fluxgate magnetometer . (Special Sensor, Magnetometer ) SSULI The ultraviolet limb imager SSUSI The ultraviolet spectrographic imager

The Copernicus ultraviolet spectral atlas of Gamma Pegasi

NASA Technical Reports Server (NTRS)

Rogerson, J. B., Jr.

1985-01-01

An ultraviolet spectral atlas is presented for the B2 IV star Gamma Pegasi, which has been scanned from 970 to 1501 A by the Princeton spectrometer aboard the Copernicus satellite. From 970 to 1430 A the observations have a nominal resolution of 0.05 A. At the longer wavelengths the resolution is 0.1 A. The atlas is presented in graphs. Line identifications are also listed.

The Copernicus ultraviolet spectral atlas of Vega

NASA Technical Reports Server (NTRS)

Rogerson, John B., Jr.

1989-01-01

A near-ultraviolet spectral atlas for the A0 V star Alpha Lyr (Vega) has been prepared from data taken by the Princeton spectrometer aboard the Copernicus satellite. The spectral region from 2000 to 3187 A has been scanned with a resolution of 0.1 A. The atlas is presented in graphs with a normalized continuum, and an identification table for the absorption features has been prepared.

The Copernicus ultraviolet spectral atlas of Tau Scorpii

NASA Technical Reports Server (NTRS)

Rogerson, J. B., Jr.; Upson, W. L., II

1977-01-01

An ultraviolet spectral atlas is presented for the B0 V star, Tau Scorpii. It has been scanned from 949 to 1560 A by the Princeton spectrometer aboard the Copernicus satellite. From 949 to 1420 A the observations have a nominal resolution of 0.05 A. At the longer wavelengths, the resolution is 0.1 A. The atlas is presented in both tables and graphs.

Powerful model for the point source sky: Far-ultraviolet and enhanced midinfrared performance

NASA Technical Reports Server (NTRS)

Cohen, Martin

1994-01-01

I report further developments of the Wainscoat et al. (1992) model originally created for the point source infrared sky. The already detailed and realistic representation of the Galaxy (disk, spiral arms and local spur, molecular ring, bulge, spheroid) has been improved, guided by CO surveys of local molecular clouds, and by the inclusion of a component to represent Gould's Belt. The newest version of the model is very well validated by Infrared Astronomy Satellite (IRAS) source counts. A major new aspect is the extension of the same model down to the far ultraviolet. I compare predicted and observed far-utraviolet source counts from the Apollo 16 'S201' experiment (1400 A) and the TD1 satellite (for the 1565 A band).

Recent advances in satellite observations of solar variability and global atmospheric ozone

NASA Technical Reports Server (NTRS)

Heath, D. F.

1974-01-01

A description is given of the temporal behavior of the sun as an ultraviolet variable star in relation to daily zonal means of atmospheric ozone from the total amount to that above the 10-mb and 4-mb pressure levels. A significant correlation has been observed between enhancements in the ultraviolet solar irradiances and terrestrial passages of the solar magnetic field sector boundary structure. However, it has not yet been possible to separate solar from the dynamical effects on the variability in the zonal means of ozone. Attention is given to global changes in ozone which have been derived from the satellite observations in terms of season, solar variability, and major stratospheric disturbances such as stratospheric warmings.

Global Auroral Remote Sensing Using GGS UVI Images

NASA Technical Reports Server (NTRS)

Germany, G. A.; Parks, G. K.; Brittnacher, M. J.; Spann, J. F., Jr.; Cumnock, J.; Lummerzheim, D.

1997-01-01

The GGS POLAR satellite, with an apogee distance of 9 Earth radii, provides an excellent platform for extended viewing of the northern auroral zone. Global FUV auroral images from the Ultraviolet Imager onboard the POLAR satellite can be used as quantitative remote diagnostics of the auroral regions, yielding estimates of incident energy characteristics, compositional changes, and other higher order data products. In particular, images of long and short wavelength Earth Far Ultraviolet (FUV) Lyman-Birge-Hopfield (LBH) emissions can be modeled to obtain functions of energy flux and average energy that are basically insensitive to changes in seasonal and solar activity changes. The determination of maps of incident auroral energy characteristics is demonstrated here and compared with in situ measurements.

Results of the AEROS satellite program: Summary

NASA Technical Reports Server (NTRS)

Lammerzahl, P.; Rawer, K.; Roemer, N.

1980-01-01

Published literature reporting aeronomic data collected on two AEROS missions is summarized. The extreme ultraviolet solar radiation and other significant parameters of the thermosphere/ionosphere were investigated. Kinetic pressure, the quantity of atomic nitrogen, and partial densities of helium, oxygen, nitrogen, argon, and atomic nitrogen were determined. The thermal electron population, superthermal energy distribution, plasma density, ion temperature, and composition according to ion types were measured. The chief energy supply in the thermosphere was calculated. Aeronomic calculations showing that variations in the parameters of the ionosphere cannot be correlated with fluctuations of extreme ultraviolet solar radiation were performed. The AEROS data were compared with data from S3-1, ISIS, and AE-C satellites. Models of the thermosphere and ionosphere were developed.

Application of the Langley plot method to the calibration of the solar backscattered ultraviolet instrument on the Nimbus 7 satellite

NASA Technical Reports Server (NTRS)

Bhartia, P. K.; Taylor, S.; Mcpeters, R. D.; Wellemeyer, C.

1995-01-01

The concept of the well-known Langley plot technique, used for the calibration of ground-based instruments, has been generalized for application to satellite instruments. In polar regions, near summer solstice, the solar backscattered ultraviolet (SBUV) instrument on the Nimbus 7 satellite samples the same ozone field at widely different solar zenith angles. These measurements are compared to assess the long-term drift in the instrument calibration. Although the technique provides only a relative wavelength-to-wavelength calibration, it can be combined with existing techniques to determine the drift of the instrument at any wavelength. Using this technique, we have generated a 12-year data set of ozone vertical profiles from SBUV with an estimated accuracy of +/- 5% at 1 mbar and +/- 2% at 10 mbar (95% confidence) over 12 years. Since the method is insensitive to true changes in the atmospheric ozone profile, it can also be used to compare the calibrations of similar SBUV instruments launched without temporal overlap.

The Copernicus ultraviolet spectral atlas of Beta Orionis

NASA Technical Reports Server (NTRS)

Rogerson, J. B., Jr.; Upson, W. L., II

1982-01-01

An ultraviolet spectral atlas is presented for the B8 Ia star Beta Orionis, which has been scanned from 999 to 1561 A by the Princeton spectrometer aboard the Copernicus satellite. From 999 to 1420 A the observations have a nominal resolution of 0.05 A. At the longer wavelengths the resolution is 0.1 A. The atlas is presented in graphs. Lines identified in the spectrum are also listed.

Satellite Atmospheric Radiance Measurements in the Vacuum Ultraviolet.

DTIC Science & Technology

1979-07-05

APERTURE I I 1_ _~~J ;~- WHEEL MOTOR IDRIVE r~~ II I :_-~I ~~~~~~~~~~~~~~~~~~ ~~~_I ~~APERT URE WHEEL\\ ELLIPSOIDAL PRIMARY MIRROR VV ~ V SUNSHADE V I...Table 1. Vacuum Ultraviolet Backg rounds Sensors (Cont ) P~ iot ometer Interf erence Filters (A) 1216 1340 1550 1750 no f

Next-Generation Fire Extinguishing Agent. Phase 4. Foundation for New Training Agent Development

DTIC Science & Technology

1989-12-01

Administration PCE perchloroethylene PEL Permissible Exposure Limit QSAR Quantitative Structure Activity Relationship SBUV Solar Backscatter Ultraviolet xi...can pass through the troposphere without destruction to enter the stratosphere. In the stratosphere, they photolyze in the intense solar radiation to...radiation, UV-B, striking the earth. Preliminary data from a Solar Backscatter Ultraviolet (SBUV) instrument aboard NASA’s Nimbus 7 satellite show a

The Copernicus ultraviolet spectral atlas of Iota Herculis

NASA Technical Reports Server (NTRS)

Upson, W. L., II; Rogerson, J. B., Jr.

1980-01-01

An ultraviolet spectral atlas is presented for the B3 IV star Iota Herculis, which has been scanned from 999 to 1467 A by the Princeton spectrometer aboard the Copernicus satellite. From 999 to 1422 A the observations have a nominal resolution of 0.05 A. At the longer wavelengths the resolution is 0.1 A. The atlas is presented in graphs. Lines identified in the spectrum are also listed.

GOES EXIS Quadruplets Together in a Clean Room "Nursery"

NASA Image and Video Library

2014-02-10

Four Extreme Ultraviolet and X-ray Irradiance Sensors or EXIS instruments that will fly aboard four of NOAA's Geostationary Operational Environmental Satellite-R or GOES-R Series spacecraft were recently lined up like babies in a nursery. The EXIS Team at NOAA's Laboratory for Atmospheric and Space Physics (LASP) in Boulder, Colorado took a short timeout during the week of January 20, 2014 to take advantage of a rare photo opportunity. Each EXIS instrument will fly aboard one of the GOES-R series of spacecraft that include GOES-R, S, T, and U. All four EXIS instruments happened to be in the clean room at the same time. It is expected that this will probably be the last time that all four siblings will be in one place together as Flight Model 1 (seen on the left) is being shipped on February 3 to begin integration and testing onto the GOES-R spacecraft at a Lockheed Martin facility in Littleton, Colo. The other instruments have already dispersed to other areas at LASP for continued build and test operations. The EXIS instruments on the GOES-R series satellites are critical to understanding and monitoring solar irradiance in the upper atmosphere, that is, the power and effect of the Sun’s electromagnetic radiation per unit of area. EXIS will be able to detect solar flares that could interrupt communications and reduce navigational accuracy, affecting satellites, high altitude airlines and power grids on Earth. On board the EXIS are two main sensors, the Extreme Ultraviolet Sensor (EUVS) and the X-Ray Sensor (XRS), which will help scientists monitor activity on the sun. The GOES-R series is a collaborative development and acquisition effort between the National Oceanic and Atmospheric Administration and NASA. The GOES-R satellites will provide continuous imagery and atmospheric measurements of Earth’s Western Hemisphere and space weather monitoring. For more information about the GOES-R series, visit: www.goes-r.gov Credit: NOAA/NASA NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Infrared Astronomy Professional Development for K-12 Educators: WISE Telescope

NASA Astrophysics Data System (ADS)

Borders, Kareen; Mendez, B. M.

2010-01-01

K-12 educators need effective and relevant astronomy professional development. WISE Telescope (Wide-Field Infrared Survey Explorer) and Spitzer Space Telescope Education programs provided an immersive teacher professional development workshop at Arecibo Observatory in Puerto Rico during the summer of 2009. As many common misconceptions involve scale and distance, teachers worked with Moon/Earth scale, solar system scale, and distance of objects in the universe. Teachers built and used basic telescopes, learned about the history of telescopes, explored ground and satellite based telescopes, and explored and worked on models of WISE Telescope. An in-depth explanation of WISE and Spitzer telescopes gave participants background knowledge for infrared astronomy observations. We taught the electromagnetic spectrum through interactive stations. The stations included an overview via lecture and power point, the use of ultraviolet beads to determine ultraviolet exposure, the study of WISE lenticulars and diagramming of infrared data, listening to light by using speakers hooked up to photoreceptor cells, looking at visible light through diffraction glasses and diagramming the data, protocols for using astronomy based research in the classroom, and infrared thermometers to compare environmental conditions around the observatory. An overview of LIDAR physics was followed up by a simulated LIDAR mapping of the topography of Mars. We will outline specific steps for K-12 infrared astronomy professional development, provide data demonstrating the impact of the above professional development on educator understanding and classroom use, and detail future plans for additional K-12 professional development. Funding was provided by WISE Telescope, Spitzer Space Telescope, Starbucks, Arecibo Observatory, the American Institute of Aeronautics and Astronautics, and the Washington Space Grant Consortium.

Electrodynamic Dust Shield Technology for Thermal Radiators Used in Lunar Exploration

NASA Technical Reports Server (NTRS)

Calle, Carlos I.; Hogue, Michael D.; Snyder, Sarah J.; Clements, Sidney J.; Johansen, Michael R.; Chen, Albert

2011-01-01

Two general types of thermal radiators are being considered for lunar missions: coated metallic surfaces and Second Surface Mirrors. Metallic surfaces are coated with a specially formulated white paint that withstands the space environment and adheres well to aluminium, the most common metal used in space hardware. AZ-93 White Thermal Control Paint, developed for the space program, is an electrically conductive inorganic coating that offers thermal control for spacecraft. It is currently in use on satellite surfaces (Fig 1). This paint withstands exposure to atomic oxygen, charged particle radiation, and vacuum ultraviolet radiation form 118 nm to 170 nm while reflecting 84 to 85% of the incident solar radiation and emitting 89-93% of the internal heat generated inside the spacecraft.

System definition phase and acquisition phase project plan for Small Astronomy Satellite SAS-D

NASA Technical Reports Server (NTRS)

1971-01-01

The objective of the SAS-D project is to conduct spectral distribution studies of celestial ultraviolet sources using an Explorer-class spacecraft launched by a Delta vehicle into a geosynchronous orbit in the last half of 1975. The telescope system is intended for use by guest astronomers for a major portion of the total observing time. The concept of the overall system, designed to resemble functionally the operation of a ground-based observatory, should maximize the usefulness of the instrument to the astronomical community by limiting the amount of special instruction needed to use the spaceborne telescope. The SAS-D mission will obtain information on what stars, nebulae, and galaxies are and how they develop.

Pegasus XL GALEX

NASA Image and Video Library

2003-03-13

In the Multi-Payload Processing Facility, the Pegasus XL launch vehicle is in position for mating of the Galaxy Evolution Explorer (GALEX) satellite. The GALEX, set to launch April 2 from Cape Canaveral Air Force Station, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

Pegasus XL GALEX

NASA Image and Video Library

2003-03-13

In the Multi-Payload Processing Facility, the Pegasus XL launch vehicle waits for mating of the Galaxy Evolution Explorer (GALEX) satellite. The GALEX, set to launch April 2 from Cape Canaveral Air Force Station, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1238

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - The mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite arrive at Cape Canaveral Air Force Station. The GALEX, to be launched April 28 from an Orbital Sciences L-1011 aircraft, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

Ultraviolet Views of Enceladus, Tethys, and Dione

NASA Technical Reports Server (NTRS)

Hansen, C. J.; Hendrix, A. R.

2005-01-01

The Cassini Ultraviolet Imaging Spectrograph (UVIS) has collected ultraviolet observations of many of Saturn's icy moons since Cassini's insertion into orbit around Saturn. We will report on results from Enceladus, Tethys and Dione, orbiting in the Saturn system at distances of 3.95, 4.88 and 6.26 Saturn radii, respectively. Icy satellite science objectives of the UVIS include investigations of surface age and evolution, surface composition and chemistry, and tenuous exospheres. We address these objectives by producing albedo maps, and reflection and emission spectra, and observing stellar occultations. UVIS has four channels: EUV: Extreme Ultraviolet (55 nm to 110 nm), FUV: Far Ultraviolet (110 to 190 nm), HSP: High Speed Photometer, and HDAC: Hydrogen-Deuterium Absorption Cell. The EUV and FUV spectrographs image onto a 2-dimensional detector, with 64 spatial rows by 1024 spectral columns. To-date we have focused primarily on the far ultraviolet data acquired with the low resolution slit width (4.8 angstrom spectral resolution). Additional information is included in the original extended abstract.

Ultraviolet emissions from the magnetic footprints of Io, Ganymede and Europa on Jupiter.

PubMed

Clarke, J T; Ajello, J; Ballester, G; Ben Jaffel, L; Connerney, J; Gérard, J-C; Gladstone, G R; Grodent, D; Pryor, W; Trauger, J; Waite, J H

2002-02-28

Io leaves a magnetic footprint on Jupiter's upper atmosphere that appears as a spot of ultraviolet emission that remains fixed underneath Io as Jupiter rotates. The specific physical mechanisms responsible for generating those emissions are not well understood, but in general the spot seems to arise because of an electromagnetic interaction between Jupiter's magnetic field and the plasma surrounding Io, driving currents of around 1 million amperes down through Jupiter's ionosphere. The other galilean satellites may also leave footprints, and the presence or absence of such footprints should illuminate the underlying physical mechanism by revealing the strengths of the currents linking the satellites to Jupiter. Here we report persistent, faint, far-ultraviolet emission from the jovian footprints of Ganymede and Europa. We also show that Io's magnetic footprint extends well beyond the immediate vicinity of Io's flux-tube interaction with Jupiter, and much farther than predicted theoretically; the emission persists for several hours downstream. We infer from these data that Ganymede and Europa have persistent interactions with Jupiter's magnetic field despite their thin atmospheres.

An Overview of the Design and Development of the Geostationary Operational Environmental Satellite R-Series (GOES-R) Space Segment

NASA Technical Reports Server (NTRS)

Sullivan, Pamela C.; Krimchansky, Alexander; Walsh, Timothy J.

2017-01-01

The first of the National Oceanic and Atmospheric Administration (NOAA) Geostationary Operational Environmental Satellite R-series (GOES-R) satellites was launched in November 2016. GOES-R has been developed by NOAA in partnership with the National Aeronautics and Space Administration (NASA). The satellite represents a quantum leap in the state of the art for geostationary weather satellites by providing data from a suite of six new instruments. All instruments were developed expressly for this mission, and include two Earth-observing instruments (the Advanced Baseline Imager (ABI) and Geostationary Lightning Mapper (GLM)), two solar-viewing instruments (Solar Ultraviolet Imager (SUVI) and Extreme ultraviolet and X-ray Irradiance Sensors (EXIS)) and two in situ instruments (Space Environment In-Situ Suite (SEISS) and a magnetometer pair). In addition to hosting the instruments, GOES-R also accommodates several communication packages designed to collect and relay data for weather forecasting and emergency management. Accommodating the six instruments and four communication payloads imposed challenging and competing constraints on the satellite, including requirements for extremely stable earth and solar pointing, high-speed and nearly error-free instrument data transmission, and a very quiet electromagnetic background. To meet mission needs, GOES-R employed several technological innovations, including low-thrust rocket engines that allow instrument observations to continue during maneuvers, and the first civilian use of Global Positioning System-based orbit determination in geostationary orbit. This paper will provide a brief overview of the GOES-R satellite and its instruments as well as the developmental challenges involved in accommodating the instruments and communications payloads.

The Ultraviolet Total Ozone Unit (TOU) IN-ORBIT PERFORMANCE AND CALIBRATION

NASA Astrophysics Data System (ADS)

Wang, Yongmei; Fu, Liping; Zhang, Zhongmou

The Ultraviolet Total Ozone Unit (TOU) was launched on 27 May 2008 on FY-3 meteorological satellite. The main purpose of TOU is to measure the incident solar radiation and backscattered ultraviolet radiance for retrieving daily global map of atmospheric ozone. TOU is a fixed grating and slit-array Ebert-Fastie grating spectrograph system. It has the multi-wavelengths detecting and two-dimensional scanning which enables global daily ground coverage. This paper discusses the recent working status of the instrument, including the sensitivity, measuring precision of solar irradiance, diffuser degradation and wavelength drift, and then presents the in-flight calibration and performance results.

The Chemistry and Excitation of Water in Molecular Clouds

NASA Technical Reports Server (NTRS)

Hollenbach, David

2003-01-01

We model the chemistry and thermal balance of opaque molecular clouds exposed to an external flux of ultraviolet photons. We include the processes of gas phase and grain surface chemical reactions; in particular we examine closely the freezing of atoms and molecules onto grain surfaces and the desorption of molecules from grain surfaces as a function of depth into a molecular cloud. We find that on the surface of a molecular cloud the gas phase water abundances are low because of photodissociation, and the grain phase water (ice) abundance is low because of photodesorption of water from the grain surfaces. Deeper into the cloud, at A(sub v) less than or approximately 2-8 depending on the strength of the external ultraviolet flux, the gas phase water abundance increases with depth as the photodissociation rates decline due to dust attenuation of the ultraviolet field. However, beyond A(sub v) less than or approximately 2-8 the gas phase water abundance declines because the water freezes as water ice on the grains, and photodesorption is no longer effective in clearing the ice. A peak water abundance of about 10(exp -6) to 10(exp -7) occurs at about A(sub v) approximately 2-8, relatively independent of the gas density and the ultraviolet field. We show that such a model matches very closely the observations of the Submillimeter Wave Astronomical Satellite (SWAS), a NASA Small Explorer Mission. The model elucidates several mechanisms that have been recently invoked to understand gas phase chemistry in clouds, including-the freeze-out of molecules onto grain surface, the desorption of these molecules from the surfaces, and the abundance gradients of molecules as functions of depth into molecular clouds.

Far Ultraviolet Spectroscopy of Saturn's Icy Moon Rhea

NASA Astrophysics Data System (ADS)

Elowitz, Mark; Hendrix, Amanda; Mason, Nigel J.; Sivaraman, Bhalamurugan

2018-01-01

We present an analysis of spatially resolved, far-UV reflectance spectra of Saturn’s icy satellite Rhea, collected by the Cassini Ultraviolet Imaging Spectrograph (UVIS). In recent years ultraviolet spectroscopy has become an important tool for analysing the icy satellites of the outer solar system (1Hendrix & Hansen, 2008). Far-UV spectroscopy provides unique information about the molecular structure and electronic transitions of chemical species. Many molecules that are suspected to be present in the icy surfaces of moons in the outer solar system have broad absorption features due to electronic transitions that occur in the far-UV portion of the spectrum. The studies show that Rhea, like the other icy satellites of the Saturnian system are dominated by water-ice as evident by the 165-nm absorption edge, with minor UV absorbing contaminants. Far-UV spectra of several Saturnian icy satellites, including Rhea and Dione, show an unexplained weak absorption feature centered near 184 nm. To carry out the geochemical survey of Rhea’s surface, the UVIS observations are compared with vacuum-UV spectra of thin-ice samples measured in laboratory experiments. Thin film laboratory spectra of water-ice and other molecular compounds in the solid phase were collected at near-vacuum conditions and temperatures identical to those at the surface of Rhea. Comparison between the observed far-UV spectra of Rhea’s surface ice and modelled spectra based on laboratory absorption measurements of different non-water-ice compounds show that two possible chemical compounds could explain the 184-nm absorption feature. The two molecular compounds include simple chlorine molecules and hydrazine monohydrate. Attempts to explain the source(s) of these compounds on Rhea and the scientific implications of their possible discovery will be summarized.[1] Hendrix, A. R. & Hansen, C. J. (2008). Icarus, 193, pp. 323-333.

Extreme Ultraviolet Explorer Bright Source List

NASA Technical Reports Server (NTRS)

Malina, Roger F.; Marshall, Herman L.; Antia, Behram; Christian, Carol A.; Dobson, Carl A.; Finley, David S.; Fruscione, Antonella; Girouard, Forrest R.; Hawkins, Isabel; Jelinsky, Patrick

1994-01-01

Initial results from the analysis of the Extreme Ultraviolet Explorer (EUVE) all-sky survey (58-740 A) and deep survey (67-364 A) are presented through the EUVE Bright Source List (BSL). The BSL contains 356 confirmed extreme ultraviolet (EUV) point sources with supporting information, including positions, observed EUV count rates, and the identification of possible optical counterparts. One-hundred twenty-six sources have been detected longward of 200 A.

``Big Bang" for NASA's Buck: Nearly Three Years of EUVE Mission Operations at UCB

NASA Astrophysics Data System (ADS)

Stroozas, B. A.; Nevitt, R.; McDonald, K. E.; Cullison, J.; Malina, R. F.

1999-12-01

After over seven years in orbit, NASA's Extreme Ultraviolet Explorer (EUVE) satellite continues to perform flawlessly and with no significant loss of science capabilities. EUVE continues to produce important and exciting science results and, with reentry not expected until 2003-2004, many more such discoveries await. In the nearly three years since the outsourcing of EUVE from NASA's Goddard Space Flight Center, the small EUVE operations team at the University of California at Berkeley (UCB) has successfully conducted all aspects of the EUVE mission -- from satellite operations, science and mission planning, and data processing, delivery, and archival, to software support, systems administration, science management, and overall mission direction. This paper discusses UCB's continued focus on automation and streamlining, in all aspects of the Project, as the means to maximize EUVE's overall scientific productivity while minimizing costs. Multitasking, non-traditional work roles, and risk management have led to expanded observing capabilities while achieving significant cost reductions and maintaining the mission's historical 99 return. This work was funded under NASA Cooperative Agreement NCC5-138.

Interstellar matter research with the Copernicus satellite

NASA Technical Reports Server (NTRS)

Spitzer, L., Jr.

1976-01-01

The use of the Copernicus satellite in an investigation of interstellar matter makes it possible to study absorption lines in the ultraviolet range which cannot be observed on the ground because of atmospheric absorption effects. A brief description is given of the satellite and the instrument used in the reported studies of interstellar matter. The results of the studies are discussed, giving attention to interstellar molecular hydrogen, the chemical composition of the interstellar gas, the coronal gas between the stars, and the interstellar abundance ratio of deuterium to hydrogen.

Comparative lifetesting results for microchannel plates in windowless EUV photon detectors

NASA Technical Reports Server (NTRS)

Malina, R. F.; Coburn, K. R.

1984-01-01

Microchannel plates (MCPs) from seven manufacturers were subjected to a series of tests to determine their suitability for the Extreme Ultraviolet Explorer satellite. Comparative data are presented for sixteen MCP tandem pairs with channel length to diameter ratios (l/d) ranging from 40:1 to 60:1 and for two saturable (curved channel) MCPs with l/d's of 80:1. Results for MCPs with funnelled channel throats are also discussed. Properties of the MCPs which were monitored include: background count rate, output charge pulse height distribution (PHD), modal gain, PHD full width half maximum (FWHM), and extreme ultraviolet (EUV) photon quantum efficiency. Five detectors were chosen for further lifetime testing consisting of a mild bake to 100 C, and charge extraction to 0.01 coulombs, repeated high voltage cycling and reexposure to one atmosphere conditions. The results of these tests and their implications for the flight detectors are discussed. Erratic events in the detector background were recorded, probably due to field emission from high voltage surfaces or the absorption of water vapor into the electrode following exposure to air. The steps taken to control the detector background are discussed.

Comparison of spectral radiance responsivity calibration techniques used for backscatter ultraviolet satellite instruments

NASA Astrophysics Data System (ADS)

Kowalewski, M. G.; Janz, S. J.

2015-02-01

Methods of absolute radiometric calibration of backscatter ultraviolet (BUV) satellite instruments are compared as part of an effort to minimize pre-launch calibration uncertainties. An internally illuminated integrating sphere source has been used for the Shuttle Solar BUV, Total Ozone Mapping Spectrometer, Ozone Mapping Instrument, and Global Ozone Monitoring Experiment 2 using standardized procedures traceable to national standards. These sphere-based spectral responsivities agree to within the derived combined standard uncertainty of 1.87% relative to calibrations performed using an external diffuser illuminated by standard irradiance sources, the customary spectral radiance responsivity calibration method for BUV instruments. The combined standard uncertainty for these calibration techniques as implemented at the NASA Goddard Space Flight Center’s Radiometric Calibration and Development Laboratory is shown to less than 2% at 250 nm when using a single traceable calibration standard.

Preliminary navigation accuracy analysis for the TDRSS Onboard Navigation System (TONS) experiment on EP/EUVE

NASA Technical Reports Server (NTRS)

Gramling, C. J.; Long, A. C.; Lee, T.; Ottenstein, N. A.; Samii, M. V.

1991-01-01

A Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) is currently being developed by NASA to provide a high accuracy autonomous navigation capability for users of TDRSS and its successor, the Advanced TDRSS (ATDRSS). The fully autonomous user onboard navigation system will support orbit determination, time determination, and frequency determination, based on observation of a continuously available, unscheduled navigation beacon signal. A TONS experiment will be performed in conjunction with the Explorer Platform (EP) Extreme Ultraviolet Explorer (EUVE) mission to flight quality TONS Block 1. An overview is presented of TONS and a preliminary analysis of the navigation accuracy anticipated for the TONS experiment. Descriptions of the TONS experiment and the associated navigation objectives, as well as a description of the onboard navigation algorithms, are provided. The accuracy of the selected algorithms is evaluated based on the processing of realistic simulated TDRSS one way forward link Doppler measurements. The analysis process is discussed and the associated navigation accuracy results are presented.

Mariner Mars 1971 project. Volume 2: Preliminary science results

NASA Technical Reports Server (NTRS)

1972-01-01

Data from six Mariner Mars experiments are presented. Television reconnaissance of Mars and its satellites yielded information on atmospheric phenomena, surface features of the South Polar region, geology, and satellite astronomy. Other experiments involved infrared spectroscopy and radiometry; ultraviolet spectrometry; S band occultation for observing the atmosphere, ionosphere, and topography of Mars; and the use of celestial mechanics, to determine the gravity field pole direction of the planet.

Field-of-View Guiding Camera on the HISAKI (SPRINT-A) Satellite

NASA Astrophysics Data System (ADS)

Yamazaki, A.; Tsuchiya, F.; Sakanoi, T.; Uemizu, K.; Yoshioka, K.; Murakami, G.; Kagitani, M.; Kasaba, Y.; Yoshikawa, I.; Terada, N.; Kimura, T.; Sakai, S.; Nakaya, K.; Fukuda, S.; Sawai, S.

2014-11-01

HISAKI (SPRINT-A) satellite is an earth-orbiting Extreme UltraViolet (EUV) spectroscopic mission and launched on 14 Sep. 2013 by the launch vehicle Epsilon-1. Extreme ultraviolet spectroscope (EXCEED) onboard the satellite will investigate plasma dynamics in Jupiter's inner magnetosphere and atmospheric escape from Venus and Mars. EUV spectroscopy is useful to measure electron density and temperature and ion composition in plasma environment. EXCEED also has an advantage to measure spatial distribution of plasmas around the planets. To measure radial plasma distribution in the Jovian inner magnetosphere and plasma emissions from ionosphere, exosphere and tail separately (for Venus and Mars), the pointing accuracy of the spectroscope should be smaller than spatial structures of interest (20 arc-seconds). For satellites in the low earth orbit (LEO), the pointing displacement is generally caused by change of alignment between the satellite bus module and the telescope due to the changing thermal inputs from the Sun and Earth. The HISAKI satellite is designed to compensate the displacement by tracking the target with using a Field-Of-View (FOV) guiding camera. Initial checkout of the attitude control for the EXCEED observation shows that pointing accuracy kept within 2 arc-seconds in a case of "track mode" which is used for Jupiter observation. For observations of Mercury, Venus, Mars, and Saturn, the entire disk will be guided inside slit to observe plasma around the planets. Since the FOV camera does not capture the disk in this case, the satellite uses a star tracker (STT) to hold the attitude ("hold mode"). Pointing accuracy during this mode has been 20-25 arc-seconds. It has been confirmed that the attitude control works well as designed.

Ultraviolet, X-ray, and infrared observations of HDE 226868 equals Cygnus X-1

NASA Technical Reports Server (NTRS)

Treves, A.; Chiappetti, L.; Tanzi, E. G.; Tarenghi, M.; Gursky, H.; Dupree, A. K.; Hartmann, L. W.; Raymond, J.; Davis, R. J.; Black, J.

1980-01-01

During April, May, and July of 1978, HDE 226868, the optical counterpart of Cygnus X-1, was repeatedly observed in the ultraviolet with the IUE satellite. Some X-ray and infrared observations have been made during the same period. The general shape of the spectrum is that expected from a late O supergiant. Strong absorption features are apparent in the ultraviolet, some of which have been identified. The equivalent widths of the most prominent lines appear to be modulated with the orbital phase. This modulation is discussed in terms of the ionization contours calculated by Hatchett and McCray, for a binary X-ray source in the stellar wind of the companion.

Vehicle/Atmosphere Interaction Glows: Far Ultraviolet, Visible, and Infrared

NASA Technical Reports Server (NTRS)

Swenson, G.

1999-01-01

Spacecraft glow information has been gathered from a number of spacecraft including Atmospheric and Dynamic satellites, and Space Shuttles (numerous flights) with dedicated pallet flow observations on STS-39 (DOD) and STS-62 (NASA). In addition, a larger number of laboratory experiments with low energy oxygen beam studies have made important contributions to glow understanding. The following report provides information on three engineering models developed for spacecraft glow including the far ultraviolet to ultraviolet (1400-4000 A), and infrared (0.9-40 microns) spectral regions. The models include effects resulting from atmospheric density/altitude, spacecraft temperature, spacecraft material, and ram angle. Glow brightness would be predicted as a function of distance from surfaces for all wavelengths.

Ultraviolet spectrometer experiment for the Voyager mission

NASA Technical Reports Server (NTRS)

Broadfoot, A. L.; Sandel, B. R.; Shemansky, D. E.; Atreya, S. K.; Donahue, T. M.; Moos, H. W.; Bertaux, J. L.; Blamont, J. E.; Ajello, J. M.; Strobel, D. F.

1977-01-01

An objective grating spectrometer covering the wavelength range of 500 to 1700 A with a 10-A resolution is employed for the Voyager ultraviolet spectrometer experiment. In determining the composition and structure of the atmospheres of Saturn, Jupiter and several satellites, the ultraviolet spectrometer will rely on airglow mode observations to measure radiation from the atmospheres due to resonant scattering of solar flux, and the occultation mode for assessments of the atmospheric extinction of solar or stellar radiation as the spacecraft enters shadow zones. Since it is capable of prolonged stellar observations in the 500 to 1000 A wavelength range, the spectrometer is expected to make important contributions to exploratory studies of UV sources.

The evolution of the quasar continuum

NASA Technical Reports Server (NTRS)

Elvis, M.

1992-01-01

We now have in hand a large data base of Roentgen Satellite (ROSAT), optical, and IR complementary data. We are in the process of obtaining a large amount of the International Ultraviolet Explorer (IUE) data for the same quasar sample. For our complementary sample at high redshifts, where the UV was redshifted into the optical, we have just had approved large amounts of observing time to cover the quasar continuum in the near-IR using the new Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) array spectrographs. Ten micron, optical, and VLA radio, data also have approved time. An ISO US key program was approved to extend this work into the far-IR, and the launch of ASTRO-D (early in 1993) promises to extend it to higher energy X-rays.

Long-term stability of the Io high-temperature plasma torus

NASA Technical Reports Server (NTRS)

Moos, H. W.; Skinner, T. E.; Durrance, S. T.; Feldman, P. D.; Festou, M. C.

1985-01-01

The short wavelength camera of the International Ultraviolet Explorer satellite was used to measure S II 1256, S III 1199, semiforbidden S III 1729, and semiforbidden S IV 1406 emission from the high-temperature region of the Io plasma torus. Observations over a period of five years (1979-1984) indicate that the Io plasma parameters have relatively small variations, particularly in the case of the mixing ratio for the dominant constituent S(++), and electron temperature. A simple three-dimensional model of the plasma torus was used to obtain the ion mixing ratios and the plasma density for each observation. The results are compared with Voyager 1 data for mixing ratio (ion density divided by electron density); ionization balance; and plasma density. The results of the comparison are discussed in detail.

Observations from earth orbit and variability of the polar aurora on Jupiter

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Moos, H. W.; Atreya, S. K.; Lane, A. L.

1980-01-01

Spatially resolved spectra of Jupiter taken with the International Ultraviolet Explorer satellite show enhanced emissions from the polar regions at H L-alpha (1216 A) and in the Lyman and Werner bands of H2 (1175-1650 A). Two types of variability in emission brightness have been observed in these aurorae: an increase in the observed emission as the auroral oval rotates with Jupiter's magnetic pole to face toward the earth and a general variation in brightness of more than an order of magnitude under nearly identical observing conditions. In addition, the spectral character of these aurorae (determined by the ratio of H L-alpha to H2 brightnesses) appears variable, indicating that the depth of penetration of the auroral particles is not constant.

Determining the atmospheric structure and dynamics of the FK Comae Star HD32918

NASA Technical Reports Server (NTRS)

Robinson, R. D.

1995-01-01

The results of UV observations taken with the International Ultraviolet Explorer (IUE) satellite and microwave observations obtained with the Australia Telescope during an observing campaign of the rapidly rotating K0 dwarf star HD 197890, nicknamed 'Speedy Mic' are presented. This star was recently recognized as a powerful, transient EUV source by the ROSAT WFC, and subsequent investigation showed it to be a ZAMS or possibly a PMS dwarf which may be a member of the Local Association. Our observations show it to have strong, variable UV emission lines near the 'saturation' levels. The radio observations show a level of 'quiescent' emission consistent with other rapidly rotating stars, but there is no evidence for the large flux variations that normally characterize the time history of such objects.

KSC-03pd1244

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - At Cape Canaveral Air Force Station, workers attach the mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite to the Orbital Sciences L-1011 aircraft. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1246

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - At Cape Canaveral Air Force Station, workers finish attaching the mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite to the Orbital Sciences L-1011 aircraft. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1241

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - The mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite move under the Orbital Sciences L-1011 aircraft at Cape Canaveral Air Force Station. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1243

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - At Cape Canaveral Air Force Station, workers prepare to attach the mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite to the Orbital Sciences L-1011 aircraft. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1240

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - In the early morning light, the mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite are seen near the Orbital Sciences L-1011 aircraft at Cape Canaveral Air Force Station. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1242

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - The mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite are moved into position under the Orbital Sciences L-1011 aircraft at Cape Canaveral Air Force Station. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1245

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - At Cape Canaveral Air Force Station, workers finish attaching the mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite to the Orbital Sciences L-1011 aircraft. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1247

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - At Cape Canaveral Air Force Station, the Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite are mated to the Orbital Sciences L-1011 aircraft. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1239

NASA Image and Video Library

2003-04-24

KENNEDY SPACE CENTER, FLA. - The mated Pegasus XL and Galaxy Evolution Explorer (GALEX) satellite approach the Orbital Sciences L-1011 aircraft at Cape Canaveral Air Force Station. The GALEX, to be launched April 28 from the L-1011, will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

Shutter mechanism for spacecraft spectrophotometer

NASA Technical Reports Server (NTRS)

Weilbach, A.

1972-01-01

A shutter mechanism is described for the backscatter ultraviolet spectrophotometer experiment on the Nimbus D satellite. The purpose of the experiment is to determine spatial distribution of atmospheric ozone from measurements of ultraviolet radiation backscattered by the earth's atmosphere. The system consists of two independent, rotary cylinder shutters, controlled by a dual star Geneva mechanism, and driven by a single stepper motor. A single driver controls a combination of two independently driven Geneva stars. Design considerations involved the use of low friction, nonmetallic materials.

Detection of latent fingerprints by ultraviolet spectral imaging

NASA Astrophysics Data System (ADS)

Huang, Wei; Xu, Xiaojing; Wang, Guiqiang

2013-12-01

Spectral imaging technology research is becoming more popular in the field of forensic science. Ultraviolet spectral imaging technology is an especial part of the full spectrum of imaging technology. This paper finished the experiment contents of the ultraviolet spectrum imaging method and image acquisition system based on ultraviolet spectral imaging technology. Ultraviolet spectral imaging experiments explores a wide variety of ultraviolet reflectance spectra of the object material curve and its ultraviolet spectrum of imaging modalities, can not only gives a reference for choosing ultraviolet wavelength to show the object surface potential traces of substances, but also gives important data for the ultraviolet spectrum of imaging technology development.

An Overview of the Design and Development of the GOES R-Series Space Segment

NASA Technical Reports Server (NTRS)

Sullivan, Pam; Krimchansky, Alexander; Walsh, Timothy

2017-01-01

The first of the National Oceanic and Atmospheric Administration (NOAA) Geostationary Operational Environmental Satellite R-series (GOES-R) satellites was launched in November 2016. GOES-R has been developed by NOAA in partnership with the National Aeronautics and Space Administration (NASA). The satellite represents a quantum leap in the state of the art for geostationary weather satellites by providing data from a suite of six new instruments. All instruments were developed expressly for this mission, and include two Earth-observing instruments (the Advanced Baseline Imager (ABI) and Geostationary Lightning Mapper (GLM)), two solar-viewing instruments (Solar Ultraviolet Imager (SUVI) and Extreme ultraviolet and X-ray Irradiance Sensors (EXIS)) and two in situ instruments (Space Environment In-Situ Suite (SEISS) and a magnetometer pair). In addition to hosting the instruments, GOES-R also accommodates several communication packages designed to collect and relay data for weather forecasting and emergency management. Accommodating the six instruments and four communication payloads imposed challenging and competing constraints on the satellite, including requirements for extremely stable earth and solar pointing, high-speed and nearly error-free instrument data transmission, and a very quiet electromagnetic background. To meet mission needs, GOES-R employed several technological innovations, including low-thrust rocket engines that allow instrument observations to continue during maneuvers, and the first civilian use of Global Positioning System-based orbit determination in geostationary orbit. This paper will provide a brief overview of the GOES-R satellite and its instruments as well as the developmental challenges involved in accommodating the instruments and communications payloads.

Analysis of air pollution over Hanoi, Vietnam using multi-satellite and MERRA reanalysis datasets.

PubMed

Lasko, Kristofer; Vadrevu, Krishna Prasad; Nguyen, Thanh Thi Nhat

2018-01-01

Air pollution is one of the major environmental concerns in Vietnam. In this study, we assess the current status of air pollution over Hanoi, Vietnam using multiple different satellite datasets and weather information, and assess the potential to capture rice residue burning emissions with satellite data in a cloud-covered region. We used a timeseries of Ozone Monitoring Instrument (OMI) Ultraviolet Aerosol Index (UVAI) satellite data to characterize absorbing aerosols related to biomass burning. We also tested a timeseries of 3-hourly MERRA-2 reanalysis Black Carbon (BC) concentration data for 5 years from 2012-2016 and explored pollution trends over time. We then used MODIS active fires, and synoptic wind patterns to attribute variability in Hanoi pollution to different sources. Because Hanoi is within the Red River Delta where rice residue burning is prominent, we explored trends to see if the residue burning signal is evident in the UVAI or BC data. Further, as the region experiences monsoon-influenced rainfall patterns, we adjusted the BC data based on daily rainfall amounts. Results indicated forest biomass burning from Northwest Vietnam and Laos impacts Hanoi air quality during the peak UVAI months of March and April. Whereas, during local rice residue burning months of June and October, no increase in UVAI is observed, with slight BC increase in October only. During the peak BC months of December and January, wind patterns indicated pollutant transport from southern China megacity areas. Results also indicated severe pollution episodes during December 2013 and January 2014. We observed significantly higher BC concentrations during nighttime than daytime with peaks generally between 2130 and 0030 local time. Our results highlight the need for better air pollution monitoring systems to capture episodic pollution events and their surface-level impacts, such as rice residue burning in cloud-prone regions in general and Hanoi, Vietnam in particular.

Analysis of air pollution over Hanoi, Vietnam using multi-satellite and MERRA reanalysis datasets

PubMed Central

Vadrevu, Krishna Prasad; Nguyen, Thanh Thi Nhat

2018-01-01

Air pollution is one of the major environmental concerns in Vietnam. In this study, we assess the current status of air pollution over Hanoi, Vietnam using multiple different satellite datasets and weather information, and assess the potential to capture rice residue burning emissions with satellite data in a cloud-covered region. We used a timeseries of Ozone Monitoring Instrument (OMI) Ultraviolet Aerosol Index (UVAI) satellite data to characterize absorbing aerosols related to biomass burning. We also tested a timeseries of 3-hourly MERRA-2 reanalysis Black Carbon (BC) concentration data for 5 years from 2012–2016 and explored pollution trends over time. We then used MODIS active fires, and synoptic wind patterns to attribute variability in Hanoi pollution to different sources. Because Hanoi is within the Red River Delta where rice residue burning is prominent, we explored trends to see if the residue burning signal is evident in the UVAI or BC data. Further, as the region experiences monsoon-influenced rainfall patterns, we adjusted the BC data based on daily rainfall amounts. Results indicated forest biomass burning from Northwest Vietnam and Laos impacts Hanoi air quality during the peak UVAI months of March and April. Whereas, during local rice residue burning months of June and October, no increase in UVAI is observed, with slight BC increase in October only. During the peak BC months of December and January, wind patterns indicated pollutant transport from southern China megacity areas. Results also indicated severe pollution episodes during December 2013 and January 2014. We observed significantly higher BC concentrations during nighttime than daytime with peaks generally between 2130 and 0030 local time. Our results highlight the need for better air pollution monitoring systems to capture episodic pollution events and their surface-level impacts, such as rice residue burning in cloud-prone regions in general and Hanoi, Vietnam in particular. PMID:29738543

Galaxy Evolution Explorer Spies Band of Stars

NASA Image and Video Library

2007-06-20

Globular star cluster NGC 362, in a false-color image from NASA's Galaxy Evolution Explorer. Image credit: NASA/JPL-Caltech/Univ. of Virginia The Galaxy Evolution Explorer's ultraviolet eyes have captured a globular star cluster, called NGC 362, in our own Milky Way galaxy. In this new image, the cluster appears next to stars from a more distant neighboring galaxy, known as the Small Magellanic Cloud. "This image is so interesting because it allows a study of the final stages of evolution of low-mass stars in NGC 362, as well as the history of star formation in the Small Magellanic Cloud," said Ricardo Schiavon of the University of Virginia, Charlottesville, Va. Globular clusters are densely packed bunches of old stars scattered in galaxies throughout the universe. NGC 362, located 30,000 light-years away, can be spotted as the dense collection of mostly yellow-tinted stars surrounding a large white-yellow spot toward the top-right of this image. The white spot is actually the core of the cluster, which is made up of stars so closely packed together that the Galaxy Evolution Explorer cannot see them individually. The light blue dots surrounding the cluster core are called extreme horizontal branch stars. These stars used to be very similar to our sun and are nearing the end of their lives. They are very hot, with temperatures reaching up to about four times that of the surface of our sun (25,000 Kelvin or 45,500 degrees Fahrenheit). A star like our sun spends most of its life fusing hydrogen atoms in its core into helium. When the star runs out of hydrogen in its core, its outer envelope will expand. The star then becomes a red giant, which burns hydrogen in a shell surrounding its inner core. Throughout its life as a red giant, the star loses a lot of mass, then begins to burn helium at its core. Some stars will have lost so much mass at the end of this process, up to 85 percent of their envelopes, that most of the envelope is gone. What is left is a very hot ultraviolet-bright core, or extreme horizontal branch star. Blue dots scattered throughout the image are hot, young stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way located approximately 200,000 light-years away. The stars in this galaxy are much brighter intrinsically than extreme horizontal branch stars, but they appear just as bright because they are farther away. The blue stars in the Small Magellanic Cloud are only about a few tens of millions of years old, much younger than the approximately 10-million-year-old stars in NGC 362. Because NGC 362 sits on the northern edge of the Small Magellanic Cloud galaxy, the blue stars are denser toward the south, or bottom, of the image. Some of the yellow spots in this image are stars in the Milky Way galaxy that are along this line of sight. Astronomers believe that some of the other spots, particularly those closer to NGC 362, might actually be a relatively ultraviolet-dim family of stars called "blue stragglers." These stars are formed from collisions or close encounters between two closely orbiting stars in a globular cluster. "This observation could only be done with the Galaxy Evolution Explorer because it is the only ultraviolet imager available to the astronomical community with such a large field of view," said Schiavon. This image is a false-color composite, where light detected by the Galaxy Evolution Explorer's far-ultraviolet detector is colored blue, and light from the telescope's near-ultraviolet detector is red. Written by Linda Vu, Spitzer Science Center Media contact: Whitney Clavin/JPL (818) 354-4673

A Mission Concept for FUSE Operations in GFY09 and Beyond

NASA Astrophysics Data System (ADS)

Moos, H. W.; Sonneborn, G.; Blair, W. P.; Kruk, J. W.; FUSE Science Operations Team

2007-05-01

We are developing a new mission concept for the Far Ultraviolet Spectroscopic Explorer (FUSE) that would significantly reduce operating costs but would continue the availability of this unique resource into GFY09 and beyond. Launched in 1999, the FUSE satellite obtains R=20,000 spectra of astronomical sources in the far-ultraviolet (912 - 1187 A) wavelength range. The FUSE scientific instrument remains healthy and the satellite has made a remarkable recovery from attitude control problems in late 2004. We expect FUSE to remain a viable scientific tool for the foreseeable future. Current plans for FUSE operations extend through GFY2008 (Sept. 30, 2008). Key elements of this new mission concept include a) continued automation and streamlining of operations to reduce costs, and b) an emphasis on a small number of unique, high priority science programs, particularly those requiring integration times on key targets that are significantly longer than has been possible in the mission design to date. A prime example of the latter would be 100 - 400 ks integrations on selected quasars to provide much improved diagnostic power to study the intergalactic medium. Synergy with the scientific objectives of the Cosmic Origins Spectrograph (COS) program on HST, and the complementary nature of FUSE and COS data on the same sightlines, is but one major motivation for this operations model. In addition to programs emphasizing very long integrations, opportunities for other high priority targets would exist. We will describe some of the ongoing development toward such an operations model as well as the scientific drivers discussed to date. Community input on these and other science drivers for extended FUSE operations is encouraged. FUSE is operated for NASA by Johns Hopkins University under NASA contract NAS5-32985.

Remote sensing of the atmosphere from environmental satellites

NASA Technical Reports Server (NTRS)

Allison, L. J.; Wexler, R.; Laughlin, C. R.; Bandeen, W. R.

1977-01-01

Various applications of satellite remote sensing of the earth are reviewed, including (1) the use of meteorological satellites to obtain photographic and radiometric data for determining weather conditions; (2) determination of the earth radiation budget from measurements of reflected solar radiation and emitted long wave terrestrial radiation; (3) the use of microwave imagery for measuring ice and snow cover; (4) LANDSAT visual and near infrared observation of floods and crop growth; and (5) the use of the Nimbus 4 backscatter ultraviolet instrument to measure total ozone and vertical ozone distribution. Plans for future activities are also discussed.

Evaluation of gratings for the Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Mrowka, Stan; Martin, Chris; Bowyer, Stuart; Malina, Roger F.

1986-01-01

Extensive grating calibration facilities have been developed at the Space Sciences Laboratory at Berkley, which are now being used for the evaluation of the gratings for the spectrometer on the Extreme Ultraviolet Explorer. Measurements of efficiency scattering and imaging quality can be made at wavelengths from 44A to 2500A.

Determining the Frequency and Structure of Mass Flows Around Herbig Ae/Be Stars

NASA Astrophysics Data System (ADS)

Johns-Krull, Christopher

One of the key scientific goals being pursued by NASA, as outlined in its Strategic Plan, is to understand how individual stars form and how those processes that affect star formation also impact the formation of planetary systems. Ultimately, we wish to know how the Earth formed and how life arose on our planet. This knowledge will lead to an understanding of whether there are other life bearing planets in our galaxy and throughout the Universe. In pursuit of this knowledge, we must consider the process of star and planetary system formation for stars of all masses so that we can test and refine our theories related to the origin of life on our planet. It is now well established that planets form in disks of gas and dust that surround newly formed stars. Key factors that determine the structure and lifetime of these disks, thereby determining the likelihood of planet formation, include how rapidly the disk material accretes onto the central star or is expelled in powerful outflows of material that are routinely observed from young stars. It is the goal of this project to study the prevalence of outflows and accretion signature in a class of young stars known as Herbig Ae/Be stars. These stars are higher mass than stars like the Sun; however, they possess unique qualities that allows us to use the study of their accretion and outflow characteristics to test our understanding of these phenomena on solar like stars. This project will combine archival International Ultraviolet Explorer (IUE) satellite data and archival Far-Ultraviolet Spectroscopic Explorer (FUSE) satellite data with spectra at other wavelengths to robustly study the incidence of accretion and outflow signatures around Herbig Ae/Be stars. The IUE and FUSE data are also sensitive to the temperature of these flows and will allow us to understand their overall structure much more completely. This overall project will comprise the PhD thesis research of a graduate student at Rice University. The budget for this proposal itself will only support the analysis of the archival IUE and FUSE data.

Post-Launch Calibration and Testing of Space Weather Instruments on GOES-R Satellite

NASA Technical Reports Server (NTRS)

Tadikonda, S. K.; Merrow, Cynthia S.; Kronenwetter, Jeffrey A.; Comeyne, Gustave J.; Flanagan, Daniel G.; Todrita, Monica

2016-01-01

The Geostationary Operational Environmental Satellite - R (GOES-R) is the first of a series of satellites to be launched, with the first launch scheduled for October 2016. The three instruments Solar UltraViolet Imager (SUVI), Extreme ultraviolet and X-ray Irradiance Sensor (EXIS), and Space Environment In-Situ Suite (SEISS) provide the data needed as inputs for the product updates National Oceanic and Atmospheric Administration (NOAA) provides to the public. SUVI is a full-disk extreme ultraviolet imager enabling Active Region characterization, filament eruption, and flare detection. EXIS provides inputs to solar back-ground-sevents impacting climate models. SEISS provides particle measurements over a wide energy-and-flux range that varies by several orders of magnitude and these data enable updates to spacecraft charge models for electrostatic discharge. EXIS and SEISS have been tested and calibrated end-to-end in ground test facilities around the United States. Due to the complexity of the SUVI design, data from component tests were used in a model to predict on-orbit performance. The ground tests and model updates provided inputs for designing the on-orbit calibration tests. A series of such tests have been planned for the Post-Launch Testing (PLT) of each of these instruments, and specific parameters have been identified that will be updated in the Ground Processing Algorithms, on-orbit parameter tables, or both. Some of SUVI and EXIS calibrations require slewing them off the Sun, while no such maneuvers are needed for SEISS. After a six-month PLT period the GOES-R is expected to be operational. The calibration details are presented in this paper.

Auroral Observations from the POLAR Ultraviolet Imager (UVI)

NASA Technical Reports Server (NTRS)

Germany, G. A.; Spann, J. F.; Parks, G. K.; Brittnacher, M. J.; Elsen, R.; Chen, L.; Lummerzheim, D.; Rees, M. H.

1998-01-01

Because of the importance of the auroral regions as a remote diagnostic of near-Earth plasma processes and magnetospheric structure, spacebased instrumentation for imaging the auroral regions have been designed and operated for the last twenty-five years. The latest generation of imagers, including those flown on the POLAR satellite, extends this quest for multispectral resolution by providing three separate imagers for the visible, ultraviolet, and X ray images of the aurora. The ability to observe extended regions allows imaging missions to significantly extend the observations available from in situ or groundbased instrumentation. The complementary nature of imaging and other observations is illustrated below using results from tile GGS Ultraviolet Imager (UVI). Details of the requisite energy and intensity analysis are also presented.

Future Directions in Ultraviolet Spectroscopy

NASA Technical Reports Server (NTRS)

Sonneborn, George (Editor); Moos, Warren; VanSteenberg, Michael

2009-01-01

The 'Future Directions in Ultraviolet Spectroscopy' conference was inspired by the accomplishments of the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission. The FUSE mission was launched in June 1999 and spent over eight years exploring the far-ultraviolet universe, gathering over 64 million seconds of high-resolution spectral data on nearly 3000 astronomical targets. The goal of this conference was not only to celebrate the accomplishments of FUSE, but to look toward the future and understand the major scientific drivers for the ultraviolet capabilities of the next generation fo space observatories. Invited speakers presented discussions based on measurements made by FUSE and other ultraviolet instruments, assessed their connection with measurements made with other techniques and, where appropriate, discussed the implications of low-z measurements for high-z phenomena. In addition to the oral presentations, many participants presented poster papers. The breadth of these presentation made it clear that much good science is still in progress with FUSE data and that these result will continue to have relevance in many scientific areas.

The test of the layout of polarimeter "UFP" on the telescope AZT-2

NASA Astrophysics Data System (ADS)

Levchenko, T. A.; Nevodovskyi, P. V.; Vidmachenko, A. P.; Morozhenko, O. V.; Saryboha, H. V.; Zbrutsky, O. V.; Ivakhiv, O. V.

2016-05-01

Main Astronomical Observatory of NAS of Ukraine in cooperation with the National Technical University of Ukraine "KPI" and National University "Lviv Polytechnic" for a long time working on the design of an optical polarimeter to study of the stratospheric layer of the Earth using of orbital satellite. During this time, was accumulated a large experience of such work, and was established a layout of compact ultraviolet polarimeter (UFP) on board of satellite

GALEX Wide-field Ultraviolet Imaging of NGC 5128 (Centaurus-A)

NASA Technical Reports Server (NTRS)

Neff, S. G.; Shiminovich, D.; Martin, C. D.

2004-01-01

We present new wide-field ultraviolet (UV) observations of the nearby active galaxy NGC 5128 (Centaurus A). The GALEX images provide 3.5 sec - 5.5 sec resolution over a 1.2 degree field, in two broad bands (1350- 1800A and 1800-3000A, centered at 1550A and 2200A). We detect ultraviolet emission associated with the radio and X-ray jets in both bands, extending out to a distance of approx. 40kpc from the galaxy nucleus. We compare the radio, X-ray, and UV jets, and discuss the feasibility of jet-induced star formation. We show how the UV emission relates to the optical filaments: HI and CO clouds, stellar shells, X-ray arcs, and young star chains previously reported by other authors. In the central region of NGC 5128, we detect UV emission from young super-star-clusters and associated ionized gas located along the near edge and on the upper surface of the dusty warped disk. All of the UV emission in the galaxy appears to result from intense star formation in the disk; none appears to be associated with the old stellar population of the main galaxy body, and no UV emission from the AGN is detected. We estimate the numbers and ages of the massive young stars present, and the associated ionized gas masses. Finally, we compare Cen-A to high redshift radio galaxies which were much more numerous in the earlier universe. The GALEX satellite is a NASA Small Explorer, launched in April 2003. We gratefully acknowledge NASA's support for construction, operation, and science analysis for the GALEX mission.

Enhanced attosecond pulse generation in the vacuum ultraviolet using a two-colour driving field for high harmonic generation

NASA Astrophysics Data System (ADS)

Matía-Hernando, P.; Witting, T.; Walke, D. J.; Marangos, J. P.; Tisch, J. W. G.

2018-03-01

High-harmonic radiation in the extreme ultraviolet and soft X-ray spectral regions can be used to generate attosecond pulses and to obtain structural and dynamic information in atoms and molecules. However, these sources typically suffer from a limited photon flux. An additional issue at lower photon energies is the appearance of satellites in the time domain, stemming from insufficient temporal gating and the spectral filtering required for the isolation of attosecond pulses. Such satellites limit the temporal resolution. The use of multi-colour driving fields has been proven to enhance the harmonic yield and provide additional control, using the relative delays between the different spectral components for waveform shaping. We describe here a two-colour high-harmonic source that combines a few-cycle near-infrared pulse with a multi-cycle second harmonic pulse, with both relative phase and carrier-envelope phase stabilization. We observe strong modulations in the harmonic flux, and present simulations and experimental results supporting the suppression of satellites in sub-femtosecond pulses at 20 eV compared to the single colour field case, an important requirement for attosecond pump-probe measurements.

Two normal incidence collimators designed for the calibration of the extreme ultraviolet explorer

NASA Technical Reports Server (NTRS)

Jelinsky, Sharon R.; Welsh, Barry; Jelinsky, Patrick; Spiller, Eberhard

1988-01-01

Two Dall-Kirkham, normal incidence collimators have been designed to calibrate the imaging properties of the Extreme Ultraviolet Explorer over the wavelength region from 114 to 2000 A. The mirrors of the short-wavelength, 25-cm diameter collimator are superpolished Zerodur which have been multilayer coated for optimal reflectivity at 114 A. The mirrors of the long-wavelength, 41.25-cm diameter collimator are gold coated Zerodur for high reflectance above 300 A. The design, performance, and future use of these collimators in the extreme ultra-violet is discussed.

The Extreme Ultraviolet Explorer mission - Overview and initial results

NASA Technical Reports Server (NTRS)

Haisch, B.; Bowyer, S.; Malina, R. F.

1993-01-01

The history of extreme ultraviolet (EUV) astronomy is briefly reviewed, and an overview of the Extreme Ultraviolet Explorer mission, launched into a near-earth (550 km) orbit on June 7, 1992, is presented. First, the principal objective of the mission are summarized. The instrumentation and operation of the mission are then described, with particular attention given to the sky survey instruments, the deep survey instrument, and the spectrometers. The discussion also covers the current view of the interstellar medium, early results from the mission, and future prospects for EUV astronomy.

The Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Malina, R. F.; Bowyer, S.; Lampton, M.; Finley, D.; Paresce, F.; Penegor, G.; Heetderks, H.

1982-01-01

The Extreme Ultraviolet Explorer Mission is described. The purpose of this mission is to search the celestial sphere for astronomical sources of extreme ultraviolet (EUV) radiation (100 to 1000 A). The search will be accomplished with the use of three EUV telescopes, each sensitive to different bands within the EUV band. A fourth telescope will perform a higher sensitivity search of a limited sample of the sky in a single EUV band. In six months, the entire sky will be scanned at a sensitivity level comparable to existing surveys in other more traditional astronomical bandpasses.

LHEA contributions to the Future of Ultraviolet Astronomy Based on Six Years of IUE Research

NASA Technical Reports Server (NTRS)

Mushotzky, R. F.; Urry, C. M.

1984-01-01

Astronomical models of galactic nuclei emission spectra are reassessed in light of ultraviolet and X-ray spectroscopic observations. Spectral analysis of BL Lacertae objects using data collected by the International Ultraviolet Explorer (IUE) and other astronomical observatories is presented.

Research in extreme ultraviolet and far ultraviolet astronomy

NASA Technical Reports Server (NTRS)

Labov, S. E.

1985-01-01

Instruments designed to explore different aspects of far and extreme ultraviolet cosmic radiation were studied. The far ultraviolet imager (FUVI) was flown on the Aries sounding rocket. Its unique large format 75mm detector mapped out the far ultraviolet background radiation with a resolution of only a few arc minutes. Analysis of this data indicates to what extent the FUVI background is extra galactic in origin. A power spectrum of the spatial fluctuations will have direct consequences for galactic evolution.

Evidence for sulphur implantation in Europa's UV absorption band

NASA Technical Reports Server (NTRS)

Lane, A. L.; Nelson, R. M.; Matson, D. L.

1981-01-01

The UV spectral characteristics of the Galilean satellites are investigated (using data from the International Ultraviolet Explorer (IUE) spacecraft) as a function of the orbital position, large-scale areal variability, and temporal dynamics. The discovery of an absorption feature at 280 nm in Europa's reflection spectrum is reported and observations show that the absorption is strongest on the trailing hemisphere (central longitude 270 degrees). The feature resembles SO2 and seems to result from S-O bond formation between deeply implanted sulphur atoms and the adjacent damaged water-ice-lattice. The sulphur supposedly comes from energetic (hundreds of keV) sulphur ions that are present in the Jovian magnetosphere. An appropriate equilibrium condition can be found to match the observed spectral data if sputtering erosion occurs at no greater than approximately 20 meters per one billion years.

An Evaluation of Attitude-Independent Magnetometer-Bias Determination Methods

NASA Technical Reports Server (NTRS)

Hashmall, J. A.; Deutschmann, Julie

1996-01-01

Although several algorithms now exist for determining three-axis magnetometer (TAM) biases without the use of attitude data, there are few studies on the effectiveness of these methods, especially in comparison with attitude dependent methods. This paper presents the results of a comparison of three attitude independent methods and an attitude dependent method for computing TAM biases. The comparisons are based on in-flight data from the Extreme Ultraviolet Explorer (EUVE), the Upper Atmosphere Research Satellite (UARS), and the Compton Gamma Ray Observatory (GRO). The effectiveness of an algorithm is measured by the accuracy of attitudes computed using biases determined with that algorithm. The attitude accuracies are determined by comparison with known, extremely accurate, star-tracker-based attitudes. In addition, the effect of knowledge of calibration parameters other than the biases on the effectiveness of all bias determination methods is examined.

Electron density diagnostics for gaseous nebulae involving the O 4 intercombination lines near 1400 A

NASA Technical Reports Server (NTRS)

Keenan, F. P.; Conlon, E. S.; Bowden, D. A.; Feibelman, W. A.; Pradhan, Anil K.

1992-01-01

Theoretical O IV electron density sensitive emission line ratios, determined using electron impact excitation rates calculated with the R-matrix code, are presented for R(sub 1) = I(1407.4 A)/I(1401.2 A), R(sub 2) = I(1404.8 A)/I(1401.2A), R(sub 3) = I(1399.8 A)/(1401.2 A), and R(sub 4) = I(1397.2 A)/I(1401.2 A). The observed values of R(sub 1)-R(sub 4), measured from high resolution spectra obtained with the International Ultraviolet Explorer (IUE) satellite, lead to electron densities that are compatible, and which are also in good agreement with those deduced from line ratios in other species. This provides observational support for the accuracy of the atomic data adopted in the present calculations.

Shuttle Atlantis to deploy Galileo probe toward Jupiter

NASA Technical Reports Server (NTRS)

1989-01-01

The objectives of Space Shuttle Mission STS-34 are described along with major flight activities, prelaunch and launch operations, trajectory sequence of events, and landing and post-landing operations. The primary objective of STS-34 is to deploy the Galileo planetary exploration spacecraft into low earth orbit. Following deployment, Galileo will be propelled on a trajectory, known as Venus-Earth-Earth Gravity Assist (VEEGA), by an inertial upper stage (IUS). The objectives of the Galileo mission are to study the chemical composition, state, and dynamics of the Jovian atmosphere and satellites, and investigate the structure and physical dynamics of the Jovian magnetosphere. Secondary STS-34 payloads include the Shuttle Solar Backscatter Ultraviolet (SSBUV) instrument; the Mesoscale Lightning Experiment (MLE); and various other payloads involving polymer morphology, the effects of microgravity on plant growth hormone, and the growth of ice crystals.

Spectroscopy and Photometry of EUVE J1429-38.0:An Eclipsing Magnetic Cataclysmic Variable

NASA Astrophysics Data System (ADS)

Howell, Steve B.; Craig, Nahide; Roberts, Bryce; McGee, Paddy; Sirk, Martin

1997-06-01

EUVE J1429-38.0 was originally discovered as a variable source by the Extreme Ultraviolet Explorer (EUVE) satellite. We present new optical observations which unambiguously confirm this star to be an eclipsing magnetic system with an orbital period of 4() h 46() m. The photometric data are strongly modulated by ellipsoidal variations during low states which allow a system inclination of near 80 degrees to be determined. Our time-resolved optical spectra, which cover only about one-third of the orbital cycle, indicate the clear presence of a gas stream. During high states, EUVE J1429-38.0 shows ~ 1 mag deep eclipses and the apparent formation of a partial accretion disk. EUVE J1429-38.0 presents the observer with properties of both the AM Herculis and the DQ Herculis types of magnetic cataclysmic variable.

Prediction of Coral Bleaching in the Florida Keys Using Remotely Sensed Data

EPA Science Inventory

Coral bleaching has been attributed to extremes or stressful synergy in several physical variables of the coral habitat. Of particular concern have been temperature, ultraviolet radiation, and photosynthetically available radiation. Satellite observing systems allow synoptic-sca...

Planning the FUSE Mission Using the SOVA Algorithm

NASA Technical Reports Server (NTRS)

Lanzi, James; Heatwole, Scott; Ward, Philip R.; Civeit, Thomas; Calvani, Humberto; Kruk, Jeffrey W.; Suchkov, Anatoly

2011-01-01

Three documents discuss the Sustainable Objective Valuation and Attainability (SOVA) algorithm and software as used to plan tasks (principally, scientific observations and associated maneuvers) for the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. SOVA is a means of managing risk in a complex system, based on a concept of computing the expected return value of a candidate ordered set of tasks as a product of pre-assigned task values and assessments of attainability made against qualitatively defined strategic objectives. For the FUSE mission, SOVA autonomously assembles a week-long schedule of target observations and associated maneuvers so as to maximize the expected scientific return value while keeping the satellite stable, managing the angular momentum of spacecraft attitude- control reaction wheels, and striving for other strategic objectives. A six-degree-of-freedom model of the spacecraft is used in simulating the tasks, and the attainability of a task is calculated at each step by use of strategic objectives as defined by use of fuzzy inference systems. SOVA utilizes a variant of a graph-search algorithm known as the A* search algorithm to assemble the tasks into a week-long target schedule, using the expected scientific return value to guide the search.

Ozone and Aerosol Retrieval from Backscattered Ultraviolet Radiation

NASA Technical Reports Server (NTRS)

Bhartia, Pawan K.

2004-01-01

In this presentation we will discuss the techniques to estimate total column ozone and aerosol absorption optical depth from the measurements of backscattered ultraviolet (buv) radiation. The total ozone algorithm has been used to create a unique record of the ozone layer, spanning more than 3 decades, from a series of instruments (BUV, SBUV, TOMS, SBUV/2) flown on NASA, NOAA, Japanese and Russian satellites. We will discuss how this algorithm can be considered a generalization of the well-known Dobson/Brewer technique that has been used to process data from ground-based instruments for many decades, and how it differs from the DOAS techniques that have been used to estimate vertical column densities of a host of trace gases from data collected by GOME and SCIAMACHY instruments. The BUV aerosol algorithm is most suitable for the detection of UV absorbing aerosols (smoke, desert dust, volcanic ash) and is the only technique that can detect aerosols embedded in clouds. This algorithm has been used to create a quarter century record of aerosol absorption optical depth using the BUV data collected by a series of TOMS instruments. We will also discuss how the data from the OM1 instrument launched on July 15,2004 will be combined with data from MODIS and CALIPSO lidar data to enhance the accuracy and information content of satellite-derived aerosol measurements. The OM1 and MODIS instruments are currently flying on EOS Aura and EOS Aqua satellites respectively, part of a constellation of satellites called the "A-train". The CALIPSO satellite is expected to join this constellation in mid 2005.

SSUSI-lite: next generation far-ultraviolet sensor for characterizing geospace

NASA Astrophysics Data System (ADS)

Paxton, Larry J.; Hicks, John E.; Grey, Matthew P.; Parker, Charles W.; Hourani, Ramsay S.; Marcotte, Kathryn M.; Carlsson, Uno P.; Kerem, Samuel; Osterman, Steven N.; Maas, Bryan J.; Ogorzalek, Bernard S.

2016-10-01

SSUSI-Lite is an update of an existing sensor, SSUSI. The current generation of Defense Meteorological Satellite Program (DMSP) satellites (Block 5D3) includes a hyperspectral, cross-tracking imaging spectrograph known as the Special Sensor Ultraviolet Spectrographic Imager (SSUSI). SSUSI has been part of the DMSP program since 1990. SSUSI is designed to provide space weather information such as: auroral imagery, ionospheric electron density profiles, and neutral density composition changes. The sensors that are flying today (see http://ssusi.jhuapl.edu) were designed in 1990 - 1992. There have been some significant improvements in flight hardware since then. The SSUSI-Lite instrument is more capable than SSUSI yet consumes ½ the power and is ½ the mass. The total package count (and as a consequence, integration cost and difficulty) was reduced from 7 to 2. The scan mechanism was redesigned and tested and is a factor of 10 better. SSUSI-Lite can be flown as a hosted payload or a rideshare - it only needs about 10 watts and weighs under 10 kg. We will show results from tests of an interesting intensified position sensitive anode pulse counting detector system. We use this approach because the SSUSI sensor operates in the far ultraviolet - from about 110 to 180 nm or 0.11 to 0.18 microns.

Mesospheric Ice particle sizes derived from two-color SME (1982-1986) and SNOE (1998- 2002) UV satellite measurements

NASA Astrophysics Data System (ADS)

Thomas, G. E.; Bailey, S. M.; Merkel, A. W.; Baumgarten, G.; Rusch, D. W.

2006-12-01

The UV spectrum of scattering from mesospheric ice particles (Polar Mesospheric Clouds) contains information on particle size, and on the microphysics of the cold summertime mesopause region. Nearly identical Ultraviolet Spectrometers were flown on both the Solar Mesosphere Explorer (SME) and Student Nitric Oxide Explorer (SNOE) satellites, both in sun-synchronous orbits reaching deep within the cold polar regions where PMC occur. The instruments measured two wavelengths simultaneously (265 and 296 nm for SME, 215 and 237 nm for SNOE), and detected PMC over a grand total of twenty PMC seasons, each covering five year periods (1982-1986 for SME) and (1998-2002 for SNOE). Using the well well-known wavelength dependence of Rayleigh scattering from thje cloud-free mesosphere we calibrate the two channels with respect to each other . The resulting accurate color ratios are then analyzed taking the brightness of the clouds into account, etc. Previous studies of the available spectral data (Rapp et al., 2006) suggested that non-spherical particles of large aspect ratios are required for consistency with the data then available. We test their results on a much more extensive data set for a large number of PMC seasons. Through the use of modern scattering theory, and predictions of the size distribution from microphysical models, such as the CARMA model, we report particle size and shape regimes which are consistent with the color ratios, obtained with different scattering geometries in both northern and southern hemispheres.

Monitoring of solar far ultraviolet radiation from the OSO-5 satellite

NASA Technical Reports Server (NTRS)

Rense, W. A.; Parker, R.

1972-01-01

A spectrophotometer for monitoring the solar EUV in three broad wavelength bands is described. The kind of data obtained, along with sources of error, are presented. The content of the tape library which contains the data is outlined. The scientific results are discussed. These include the following: solar flares in the EUV, solar eclipse observations in the EUV, SFD's and relationship to solar flares, and the application of satellite sunrise and sunset data for the study of model upper atmospheres for the earth.

Chromospheric Structure and Wind Acceleration in Zeta Aur Stars

NASA Technical Reports Server (NTRS)

Bennett, Philip D.

2001-01-01

This NASA grant supported an analysis of the variability of the wind of the supergiant primary star (K4 Ib) in the eclipsing binary Zeta Aurigae (Zeta Aur). In the ultraviolet, the main-sequence companion star (B5 V) dominates the observed flux, and therefore serves as a convenient probe of the cool supergiant's wind. This study utilized the extensive set of (100+) ultraviolet spectroscopic observations obtained with the International Ultraviolet Explorer (IUE) satellite over its operational lifetime of 1978-1995. Although the resolution of IUE is limited (about 25 km/s), it is adequate to resolve variability in the wind features in Zeta Aur's ultraviolet spectrum, which are blueshifted 70 km/s from line center. Our analysis used the tau-v technique of Cardelli and Savage, which makes full use of the available line profile information. We find that the wind column densities vary by up to an order of magnitude over time. These results are being written up for submission to the Astrophysical Journal as the third paper of a series on the chromosphere and wind of Zeta Aurigae. The first two papers report on the construction of mean chromosphere and wind models respectively, based on HST/GHRS observations and funded by STScI. The third paper - this research - reports on variability of the Zeta Aur wind as determined from our analysis of the long IUE time series. This paper will be completed within the next three months; the delay in publication was to allow the completion of Papers 1 and 2, which logically precede the present work. Therefore, an additional no-cost extension was requested in order to ensure budgeted funds remain available for publication of this work. Unfortunately, this request was denied, and so I am forced to write this final report before publication of Paper 3. Regardless, this paper will be submitted for publication within the next three months.

GALEX 1st Light Near and Far Ultraviolet -100

NASA Image and Video Library

2003-05-28

NASA's Galaxy Evolution Explorer took this image on May 21 and 22, 2003. The image was made from data gathered by the two channels of the spacecraft camera during the mission's "first light" milestone. It shows about 100 celestial objects in the constellation Hercules. The reddish objects represent those detected by the camera's near ultraviolet channel over a 5-minute period, while bluish objects were detected over a 3-minute period by the camera's far ultraviolet channel. The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. http://photojournal.jpl.nasa.gov/catalog/PIA04281

KSC-98pc1086

NASA Image and Video Library

1998-09-14

KENNEDY SPACE CENTER, FLA. The International Extreme Ultraviolet Hitchhiker-3 (IEH-3), one of the payloads for the STS-95 mission, is prepared for launch in the Multi-Payload Processing Facility. IEH-3 is comprised of seven experiments, including one that will be deployed on Flight Day 3. It is the small, non-recoverable Petite Amateur Navy Satellite (PANSAT) which will store and transmit digital communications. Other IEH investigations are the Solar Constant Experiment (SOLCON), Solar Extreme Ultraviolet Hitchhiker (SEH), Spectrograph/Telescope for Astronomical Research (STAR-LITE), Ultraviolet Spectrograph Telescope for Astronomical Research (UVSTAR), Consortium for Materials Development in Space Complex Autonomous Payloads (CONCAP-IV) for growing thin films via physical vapor transport, and two Get-Away Special (GAS) canister experiments. The experiments will be mounted on a hitchhiker bridge in Discovery's payload bay

Ultraviolet Extensions

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Side-by-Side Comparison Click on image for larger view

This ultraviolet image from NASA's Galaxy Evolution Explorer shows the Southern Pinwheel galaxy, also know as Messier 83 or M83. It is located 15 million light-years away in the southern constellation Hydra.

Ultraviolet light traces young populations of stars; in this image, young stars can be seen way beyond the main spiral disk of M83 up to 140,000 light-years from its center. Could life exist around one of these far-flung stars? Scientists say it's unlikely because the outlying regions of a galaxy are lacking in the metals required for planets to form.

The image was taken at scheduled intervals between March 15 and May 20, 2007. It is one of the longest-exposure, or deepest, images ever taken of a nearby galaxy in ultraviolet light. Near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow, and far-ultraviolet light is blue.

What Lies Beyond the Edge of a Galaxy The side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy's long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms.

The ultraviolet image was taken by NASA's Galaxy Evolution Explorer between March 15 and May 20, 2007, at scheduled intervals. Back in 2005, the telescope first photographed M83 over a shorter period of time. That picture was the first to reveal far-flung baby stars forming up to 63,000 light-years from the edge of the main spiral disk. This came as a surprise to astronomers because a galaxy's outer territory typically lacks high densities of star-forming materials.

The newest picture of M83 from the Galaxy Evolution Explorer is shown at the right, and was taken over a longer period of time. In fact, it is one of the 'deepest,' or longest-exposure, images of a nearby galaxy in ultraviolet light. This deeper view shows more clusters of stars, as well as stars in the very remote reaches of the galaxy, up to 140,000 light-years away from its core.

The view at the left is a combination of the ultraviolet picture at the right and data taken by the telescopes of the National Science Foundation's Very Large Array in New Mexico. The radio data, colored here in red, reveal extended galactic arms of gaseous hydrogen atoms, which are raw ingredients for stars. Astronomers are excited that the remote clusters of baby stars match up with the extended arms, because this helps them better understand how stars can be created out in the boondocks of a galaxy.

M83 is located 15 million light-years away in the southern constellation Hydra.

In the Galaxy Evolution Explorer image on the right, near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow and far-ultraviolet light is blue. In the combined image at the left, far-ultraviolet light is blue, near-ultraviolet light is green, and the radio emission at a wavelength of 21 centimeters is red.

Selected highlights from the Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Bowyer, S.; Malina, R. F.

1995-01-01

We present a few scientific highlights from the Extreme Ultraviolet Explorer (EUVE) all-sky and deep surveys, from the EUVE Righ Angle Program, and from the EUVE Guest Observer Program. The First EUVE Source Catalog includes 410 extreme ultraviolet (EUV) sources detected in the initial processing of the EUVE all-sky data. A program of optical identification indicates that counterparts include cool star coronae, flare stars, hot white dwarfs, central stars of planetary nebulae, B star photospheres and winds, an X-ray binary, extragalactic objects (active galactic nuclei, BL Lacertae), solar system objects (Moon, Mars, Io,), supernova remnants, and two novae.

Beyond the Borders of a Galaxy

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Side-by-Side Comparison Click on image for larger view

The outlying regions around the Southern Pinwheel galaxy, or M83, are highlighted in this composite image from NASA's Galaxy Evolution Explorer and the National Science Foundation's Very Large Array in New Mexico. The blue and pink pinwheel in the center is the galaxy's main stellar disk, while the flapping, ribbon-like structures are its extended arms.

The Galaxy Evolution Explorer is an ultraviolet survey telescope. Its observations, shown here in blue and green, highlight the galaxy's farthest-flung clusters of young stars up to 140,000 light-years from its center. The Very Large Array observations show the radio emission in red. They highlight gaseous hydrogen atoms, or raw ingredients for stars, which make up the lengthy, extended arms.

Astronomers are excited that the clusters of baby stars match up with the extended arms, because this helps them better understand how stars can be created out in the 'backwoods' of a galaxy.

In this image, far-ultraviolet light is blue, near-ultraviolet light is green and radio emission at a wavelength of 21 centimeters is red.

What Lies Beyond the Edge of a Galaxy The side-by-side comparison shows the Southern Pinwheel galaxy, or M83, as seen in ultraviolet light (right) and at both ultraviolet and radio wavelengths (left). While the radio data highlight the galaxy's long, octopus-like arms stretching far beyond its main spiral disk (red), the ultraviolet data reveal clusters of baby stars (blue) within the extended arms.

The ultraviolet image was taken by NASA's Galaxy Evolution Explorer between March 15 and May 20, 2007, at scheduled intervals. Back in 2005, the telescope first photographed M83 over a shorter period of time. That picture was the first to reveal far-flung baby stars forming up to 63,000 light-years from the edge of the main spiral disk. This came as a surprise to astronomers because a galaxy's outer territory typically lacks high densities of star-forming materials.

The newest picture of M83 from the Galaxy Evolution Explorer is shown at the right, and was taken over a longer period of time. In fact, it is one of the 'deepest,' or longest-exposure, images of a nearby galaxy in ultraviolet light. This deeper view shows more clusters of stars, as well as stars in the very remote reaches of the galaxy, up to 140,000 light-years away from its core.

The view at the left is a combination of the ultraviolet picture at the right and data taken by the telescopes of the National Science Foundation's Very Large Array in New Mexico. The radio data, colored here in red, reveal extended galactic arms of gaseous hydrogen atoms, which are raw ingredients for stars. Astronomers are excited that the remote clusters of baby stars match up with the extended arms, because this helps them better understand how stars can be created out in the boondocks of a galaxy.

M83 is located 15 million light-years away in the southern constellation Hydra.

In the Galaxy Evolution Explorer image on the right, near-ultraviolet light (or longer-wavelength ultraviolet light) is colored yellow and far-ultraviolet light is blue. In the combined image at the left, far-ultraviolet light is blue, near-ultraviolet light is green, and the radio emission at a wavelength of 21 centimeters is red.

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

47 CFR 97.303 - Frequency sharing requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... harmful interference to stations in the Earth exploration-satellite service (passive) or the space...; and (3) Other nations in the Earth exploration-satellite (active), radionavigation-satellite (space-to...: (1) The United States Government in the aeronautical radionavigation, Earth exploration-satellite...

Ultraviolet Extensions

NASA Image and Video Library

2008-04-16

This ultraviolet image from NASA Galaxy Evolution Explorer shows the Southern Pinwheel galaxy, also know as Messier 83 or M83. It is located 15 million light-years away in the southern constellation Hydra.

Proceedings of the Second Pilot Climate Data System Workshop

NASA Technical Reports Server (NTRS)

1986-01-01

The proceedings of the workshop held on January 29 and 30, 1986 are discussed. Data management, satellite radiance data, clouds, ultraviolet flux variations in the upper atmosphere, rainfall during El Nino events, and the use of optical disks are among the topics covered.

NASA Galaxy Mission Celebrates Sixth Anniversary

NASA Image and Video Library

2009-04-28

NASA Galaxy Evolution Explorer Mission celebrates its sixth anniversary studying galaxies beyond our Milky Way through its sensitive ultraviolet telescope, the only such far-ultraviolet detector in space. The mission studies the shape, brightness, size and distance of distant galaxies across 10 billion years of cosmic history, giving scientists a wealth of data to help us better understand the origins of the universe. One such object is pictured here, the galaxy NGC598, more commonly known as M33. This image is a blend of the Galaxy Evolution Explorer's M33 image and another taken by NASA's Spitzer Space Telescope. M33, one of our closest galactic neighbors, is about 2.9 million light-years away in the constellation Triangulum, part of what's known as our Local Group of galaxies. Together, the Galaxy Evolution Explorer and Spitzer can see a broad spectrum of sky. Spitzer, for example, can detect mid-infrared radiation from dust that has absorbed young stars' ultraviolet light. That's something the Galaxy Evolution Explorer cannot see. This combined image shows in amazing detail the beautiful and complicated interlacing of the heated dust and young stars. In some regions of M33, dust gathers where there is very little far-ultraviolet light, suggesting that the young stars are obscured or that stars further away are heating the dust. In some of the outer regions of the galaxy, just the opposite is true: There are plenty of young stars and very little dust. Far-ultraviolet light from young stars glimmers blue, near-ultraviolet light from intermediate age stars glows green, near-infrared light from old stars burns yellow and orange, and dust rich in organic molecules burns red. The small blue flecks outside the spiral disk of M33 are most likely distant background galaxies. This image is a four-band composite that, in addition to the two ultraviolet bands, includes near infrared as yellow/orange and far infrared as red. http://photojournal.jpl.nasa.gov/catalog/PIA11999

Ozone and Aerosol Retrieval from Backscattered Ultraviolet Radiation

NASA Technical Reports Server (NTRS)

Bhartia, Pawan K.

2012-01-01

In this presentation we will discuss the techniques to estimate total column ozone and aerosol absorption optical depth from the measurements of back scattered ultraviolet (buv) radiation. The total ozone algorithm has been used to create a unique record of the ozone layer, spanning more than 3 decades, from a series of instruments (BUV, SBUV, TOMS, SBUV/2) flown on NASA, NOAA, Japanese and Russian satellites. We will discuss how this algorithm can be considered a generalization of the well-known Dobson/Brewer technique that has been used to process data from ground-based instruments for many decades, and how it differs from the DOAS techniques that have been used to estimate vertical column densities of a host of trace gases from data collected by GOME and SCIAMACHY instruments. The buv aerosol algorithm is most suitable for the detection of UV absorbing aerosols (smoke, desert dust, volcanic ash) and is the only technique that can detect aerosols embedded in clouds. This algorithm has been used to create a quarter century record of aerosol absorption optical depth using the buv data collected by a series of TOMS instruments. We will also discuss how the data from the OMI instrument launched on July 15, 2004 will be combined with data from MODIS and CALIPSO lidar data to enhance the accuracy and information content of satellite-derived aerosol measurements. The OMI and MODIS instruments are currently flying on EOS Aura and EOS Aqua satellites respectively, part of a constellation of satellites called the "A-train".

GALEX 1st Light Far Ultraviolet

NASA Technical Reports Server (NTRS)

2003-01-01

This image was taken May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered by the far ultraviolet channel of the spacecraft camera during the mission's 'first light' milestone. It shows about 400 celestial objects, appearing in blue, detected over a 3-minute, 20-second period in the constellation Hercules.

The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas.

The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years.

Validation of an Innovative Satellite-Based UV Dosimeter

NASA Astrophysics Data System (ADS)

Morelli, Marco; Masini, Andrea; Simeone, Emilio; Khazova, Marina

2016-08-01

We present an innovative satellite-based UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in-vivo assessment of the erythemal effects on some volunteers having a controlled exposure to solar radiation.Both validations showed that the satellite-based UV dosimeter has a good accuracy and reliability needed for health-related applications.The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. This app will be launched on the global market by siHealth Ltd in May 2016 under the name of "HappySun" and available both for Android and for iOS devices (more info on http://www.happysun.co.uk).Extensive R&D activities are on-going for further improvement of the satellite-based UV dosimeter's accuracy.

NASA Galaxy Mission Celebrates Sixth Anniversary

NASA Image and Video Library

2009-04-28

NASA Galaxy Evolution Explorer Mission celebrates its sixth anniversary studying galaxies beyond our Milky Way through its sensitive ultraviolet telescope, the only such far-ultraviolet detector in space. Pictured here, the galaxy NGC598 known as M33. The mission studies the shape, brightness, size and distance of distant galaxies across 10 billion years of cosmic history, giving scientists a wealth of data to help us better understand the origins of the universe. One such object is pictured here, the galaxy NGC598, more commonly known as M33. This image is a blend of the Galaxy Evolution Explorer's M33 image and another taken by NASA's Spitzer Space Telescope. M33, one of our closest galactic neighbors, is about 2.9 million light-years away in the constellation Triangulum, part of what's known as our Local Group of galaxies. Together, the Galaxy Evolution Explorer and Spitzer can see a broad spectrum of sky. Spitzer, for example, can detect mid-infrared radiation from dust that has absorbed young stars' ultraviolet light. That's something the Galaxy Evolution Explorer cannot see. This combined image shows in amazing detail the beautiful and complicated interlacing of the heated dust and young stars. In some regions of M33, dust gathers where there is very little far-ultraviolet light, suggesting that the young stars are obscured or that stars farther away are heating the dust. In some of the outer regions of the galaxy, just the opposite is true: There are plenty of young stars and very little dust. Far-ultraviolet light from young stars glimmers blue, near-ultraviolet light from intermediate age stars glows green, and dust rich in organic molecules burns red. This image is a 3-band composite including far infrared as red. http://photojournal.jpl.nasa.gov/catalog/PIA11998

Algorithm Development and Validation of CDOM Properties for Estuarine and Continental Shelf Waters Along the Northeastern U.S. Coast

NASA Technical Reports Server (NTRS)

Mannino, Antonio; Novak, Michael G.; Hooker, Stanford B.; Hyde, Kimberly; Aurin, Dick

2014-01-01

An extensive set of field measurements have been collected throughout the continental margin of the northeastern U.S. from 2004 to 2011 to develop and validate ocean color satellite algorithms for the retrieval of the absorption coefficient of chromophoric dissolved organic matter (aCDOM) and CDOM spectral slopes for the 275:295 nm and 300:600 nm spectral range (S275:295 and S300:600). Remote sensing reflectance (Rrs) measurements computed from in-water radiometry profiles along with aCDOM() data are applied to develop several types of algorithms for the SeaWiFS and MODIS-Aqua ocean color satellite sensors, which involve least squares linear regression of aCDOM() with (1) Rrs band ratios, (2) quasi-analytical algorithm-based (QAA based) products of total absorption coefficients, (3) multiple Rrs bands within a multiple linear regression (MLR) analysis, and (4) diffuse attenuation coefficient (Kd). The relative error (mean absolute percent difference; MAPD) for the MLR retrievals of aCDOM(275), aCDOM(355), aCDOM(380), aCDOM(412) and aCDOM(443) for our study region range from 20.4-23.9 for MODIS-Aqua and 27.3-30 for SeaWiFS. Because of the narrower range of CDOM spectral slope values, the MAPD for the MLR S275:295 and QAA-based S300:600 algorithms are much lower ranging from 9.9 and 8.3 for SeaWiFS, respectively, and 8.7 and 6.3 for MODIS, respectively. Seasonal and spatial MODIS-Aqua and SeaWiFS distributions of aCDOM, S275:295 and S300:600 processed with these algorithms are consistent with field measurements and the processes that impact CDOM levels along the continental shelf of the northeastern U.S. Several satellite data processing factors correlate with higher uncertainty in satellite retrievals of aCDOM, S275:295 and S300:600 within the coastal ocean, including solar zenith angle, sensor viewing angle, and atmospheric products applied for atmospheric corrections. Algorithms that include ultraviolet Rrs bands provide a better fit to field measurements than algorithms without the ultraviolet Rrs bands. This suggests that satellite sensors with ultraviolet capability could provide better retrievals of CDOM. Because of the strong correlations between CDOM parameters and DOM constituents in the coastal ocean, satellite observations of CDOM parameters can be applied to study the distributions, sources and sinks of DOM, which are relevant for understanding the carbon cycle, modeling the Earth system, and to discern how the Earth is changing.

Evidence for a Trapped Radical (OH) on Ariel, Oberon, and Titania from Hubble Space Telescope Ultraviolet Spectra

NASA Technical Reports Server (NTRS)

Roush, Ted L.; Noll, Keith S.; Pendleton, Yvonne J.; DeVincenzi, Donald (Technical Monitor)

2000-01-01

The moons Ariel, Titania, and Oberon have orbits lying within the magnetosphere of Uranus, exposing them to particle irradiation from trapped Ions. This Is similar to the situation experienced by the jovian moons Europa, Ganymede, and Callisto, as well as the saturnian satellites Enceladus, Tethys, Dione, and Rhea. Identification of SO2 on Europa, Ganymede and Callisto, and O3 on Ganymede, Rhea, and Dione has supported suggestions that chemical modifications occur on icy bodies due to ion bombardment associated with the particles entrained within the magnetospheric fields of Jupiter and Saturn. Similar to the Jovian and saturnian satellites mentioned above, water ice is a major component on the larger uranian satellites", thus one might anticipate chemical modification to he an important process in the uranian system. Laboratory studies or the interaction of ultraviolet (uv) and charged-particle radiation with water ice show that in addition to molecular species, a variety of radicals are also produced. We report here evidence for an uv absorption feature in the spectra of Ariel, Titania, and Oberon that we identify as due, in part, to OH; providing the first evidence of a radical produced and trapped on an icy moon within our solar system.

Extreme ultraviolet spectral irradiance measurements since 1946

NASA Astrophysics Data System (ADS)

Schmidtke, G.

2015-03-01

In the physics of the upper atmosphere the solar extreme ultraviolet (EUV) radiation plays a dominant role controlling most of the thermospheric/ionospheric (T/I) processes. Since this part of the solar spectrum is absorbed in the thermosphere, platforms to measure the EUV fluxes became only available with the development of rockets reaching altitude levels exceeding 80 km. With the availability of V2 rockets used in space research, recording of EUV spectra started in 1946 using photographic films. The development of pointing devices to accurately orient the spectrographs toward the sun initiated intense activities in solar-terrestrial research. The application of photoelectric recording technology enabled the scientists placing EUV spectrometers aboard satellites observing qualitatively strong variability of the solar EUV irradiance on short-, medium-, and long-term scales. However, as more measurements were performed more radiometric EUV data diverged due to the inherent degradation of the EUV instruments with time. Also, continuous recording of the EUV energy input to the T/I system was not achieved. It is only at the end of the last century that there was progress made in solving the serious problem of degradation enabling to monitore solar EUV fluxes with sufficient radiometric accuracy. The data sets available allow composing the data available to the first set of EUV data covering a period of 11 years for the first time. Based on the sophisticated instrumentation verified in space, future EUV measurements of the solar spectral irradiance (SSI) are promising accuracy levels of about 5% and less. With added low-cost equipment, real-time measurements will allow providing data needed in ionospheric modeling, e.g., for correcting propagation delays of navigation signals from space to earth. Adding EUV airglow and auroral emission monitoring by airglow cameras, the impact of space weather on the terrestrial T/I system can be studied with a spectral terrestrial irradiance camera (STI-Cam) and also be used investigating real-time space weather effects and deriving more detailed correction procedures for the evaluation of Global Navigation Satellite System (GNSS) signals. Progress in physics goes with achieving higher accuracy in measurements. This review historically guides the reader on the ways of exploring the impact of the variable solar radiation in the extreme ultraviolet spectral region on our upper atmosphere in the altitude regime from 80 to 1000 km.

Artist concept of STS-34 SSBUV in orbit calibration

NASA Technical Reports Server (NTRS)

1989-01-01

Artist concept titled SSBUV IN ORBIT CALIBRATION shows how the shuttle solar backscatter ultraviolet (UV) (SSBUV) instrument will calibrate ozone measuring space-based instruments on the National Oceanic and Atmospheric Administration's (NOAA's) TIROS satellites NOAA-9 and NOAA-11. During STS-34, SSBUV instruments mounted in get away special (GAS) canisters in Atlantis', Orbiter Vehicle (OV) 104's, payload bay will use the Space Shuttle's orbital flight path to assess instrument performance by directly comparing data from identical instruments aboard the TIROS satellite, as OV-104 and the satellite pass over the same Earth location within a one-hour window. SSBUV is managed by NASA's Goddard Space Flight Center (GSFC). Alternate number on image is E66.001.

A Configurable Internet Telemetry Server / Remote Client System

NASA Astrophysics Data System (ADS)

Boyd, W. T.; Hopkins, A.; Abbott, M. J.; Girouard, F. R.

2000-05-01

We have created a general, object-oriented software framework in Java for remote viewing of telemetry over the Internet. The general system consists of a data server and a remote client that can be extended by any project that uses telemetry to implement a remote telemetry viewer. We have implemented a system that serves live telemetry from NASA's Extreme Ultraviolet Explorer satellite and a client that can display the telemetry at a remote location. An authenticated user may run a standalone graphical or text-based client, or an applet on a web page, to view EUVE telemetry. In the case of the GUI client, a user can build displays to his/her own specifications using a GUI view-building tool. This work was supported by grants NCC2-947 and NCC2-966 from NASA Ames Research Center and grant JPL-960684 from NASA Jet Propulsion Laboratory.

Far-ultraviolet absorption spectra of quasars: How to find missing hot gas and metals

NASA Technical Reports Server (NTRS)

Verner, D. A.; Tytler, David; Barthel, P. D.

1994-01-01

We show that some high-redshift QSO absorption systems that reveal only the H I Lyman series lines at wavelengths visible from the ground maybe a new class of ultra-high-ionization metal line systems, with metal lines in the far-UV region which is now being explored with satellites. At high temperatures or in intense radiation fields metal systems will not show the usual C IV absorption, and O VI will become the most prominent metal absorber. At still higher ionization, O IV also becomes weak and the strongest metal lines are from Ne VIII, Mg X and Si XII, which have doublets in the rangs 500-800 A. Hence very high ionization metal systems will not show metal lines in existing spectra. Recent X-ray observations show that galaxy halos contain hot gas, so we predict that far-UV spectra of QSOs will also show this gas.

Postlaunch calibration of spacecraft attitude instruments

NASA Technical Reports Server (NTRS)

Davis, W.; Hashmall, J.; Garrick, J.; Harman, R.

1993-01-01

The accuracy of both onboard and ground attitude determination can be significantly enhanced by calibrating spacecraft attitude instruments (sensors) after launch. Although attitude sensors are accurately calibrated before launch, the stresses of launch and the space environment inevitably cause changes in sensor parameters. During the mission, these parameters may continue to drift requiring repeated on-orbit calibrations. The goal of attitude sensor calibration is to reduce the systematic errors in the measurement models. There are two stages at which systematic errors may enter. The first occurs in the conversion of sensor output into an observation vector in the sensor frame. The second occurs in the transformation of the vector from the sensor frame to the spacecraft attitude reference frame. This paper presents postlaunch alignment and transfer function calibration of the attitude sensors for the Compton Gamma Ray Observatory (GRO), the Upper Atmosphere Research Satellite (UARS), and the Extreme Ultraviolet Explorer (EUVE).

X-Ray Flare Characteristics in lambda Eridani

NASA Technical Reports Server (NTRS)

Smith, Myron A.

1997-01-01

This proposal was for a joint X-ray/ultraviolet/ground-based study of the abnormal Be star lambda Eri, which has previously shown evidence of X-ray flaring from ROSAT observations in 1991. The X-ray component consisted of observations from both the ASCA and ROSAT satellites.

X-Ray Flare Characteristics in Lambda Eridani

NASA Technical Reports Server (NTRS)

Smith, Myron A.

1997-01-01

This proposal was for a joint X-ray/ultraviolet/ground-based study of the abnormal Be star lambda Eri, which has previously shown evidence of X-ray flaring from ROSAT observations in 1991. The X-ray component consisted of observations from both the ASCA and ROSAT satellites.

The Extreme Ultraviolet Explorer - Optics fabrication and performance

NASA Technical Reports Server (NTRS)

Green, J.; Finley, D.; Bowyer, S.; Malina, R. F.

1986-01-01

The fabrication methods, testing and evaluation techniques, and performance results are presented for the mirrors for the Extreme Ultraviolet Explorer (EUVE). The finest mirror produced to date has a measured half energy width of 8 arcsec at optical wavelengths. With a polished nickel surface, the telescope throughput was 35 percent at 44 A and 60 percent at 256 A. The surface roughness is 20 A rms.

IEH-3 is prepared for launch on STS-95 in the MPPF

NASA Technical Reports Server (NTRS)

1998-01-01

KENNEDY SPACE CENTER, FLA. -- The International Extreme Ultraviolet Hitchhiker-3 (IEH-3), one of the payloads for the STS-95 mission, is prepared for launch in the Multi-Payload Processing Facility. IEH-3 is comprised of seven experiments, including one that will be deployed on Flight Day 3. It is the small, non-recoverable Petite Amateur Navy Satellite (PANSAT) which will store and transmit digital communications. Other IEH investigations are the Solar Constant Experiment (SOLCON), Solar Extreme Ultraviolet Hitchhiker (SEH), Spectrograph/Telescope for Astronomical Research (STAR-LITE), Ultraviolet Spectrograph Telescope for Astronomical Research (UVSTAR), Consortium for Materials Development in Space Complex Autonomous Payloads (CONCAP-IV) for growing thin films via physical vapor transport, and two Get-Away Special (GAS) canister experiments. The experiments will be mounted on a hitchhiker bridge in Discovery's payload bay.

The measurement of ultraviolet radiation and sunburn time over southern Ontario

NASA Technical Reports Server (NTRS)

Evans, W. F. J.

1994-01-01

Studies of the depletion of ozone which have been conducted from the TOMS instrument on the NIMBUS 7 satellite indicate that total ozone has declined by 5 percent over the last 12 years at most mid-latitudes in the Northern Hemisphere typical of southern Ontario. The measurement of the actual resultant increases in UVB is now important. A monitoring program of UVB (biologically active solar ultraviolet radiation) has been conducted for the last 24 months at a site near Bolton, Ontario. The sunburn time varies from less than 17 minutes in late July, to over 4 hours in December on clear days. The levels depend on solar insolation and total ozone column. The ultraviolet levels are strongly affected by cloud and sky conditions. The implications of present and future depletion on the sunburn time are discussed.

The Ultraviolet Spectrograph (UVS) on ESA’s JUICE Mission

NASA Astrophysics Data System (ADS)

Gladstone, Randy; Retherford, K.; Steffl, A.; Eterno, J.; Davis, M.; Versteeg, M.; Greathouse, T.; Araujo, M.; Walther, B.; Persson, K.; Persyn, S.; Dirks, G.; McGrath, M.; Feldman, P.; Bagenal, F.; Spencer, J.; Schindhelm, E.; Fletcher, L.

2013-10-01

The Jupiter Icy Moons Explorer (JUICE) was selected in May 2012 as the first L-class mission of ESA’s Cosmic Vision Program. JUICE will launch in 2022 on a 7.6-year journey to the Jovian system, including a Venus and multiple Earth gravity assists, before entering Jupiter orbit in January 2030. JUICE will study the entire Jovian system for 3.5 years, concentrating on Europa, Ganymede, and Callisto, with the last 10 months spent in Ganymede orbit. The Ultraviolet Spectrograph (UVS) on JUICE was jointly selected by NASA and ESA as part of its ~130 kg payload of 11 scientific instruments. UVS is the fifth in a series of successful ultraviolet imaging spectrographs (Rosetta-Alice, New Horizons Pluto-Alice, LRO-LAMP) and is largely based on the most recent of these, Juno-UVS. It observes photons in the 55-210 nm wavelength range, at moderate spectral and spatial resolution along a 7.5-degree slit. A main entrance “airglow port” (AP) is used for most observations (e.g., airglow, aurora, surface mapping, and stellar occultations), while a separate “solar port” (SP) allows for solar occultations. Another aperture door, with a small hole through the centre, is used as a “high-spatial-resolution port” (HP) for detailed observations of bright targets. Time-tagging (pixel list mode) and programmable spectral imaging (histogram mode) allow for observational flexibility and optimal data management. As on Juno-UVS, the effects of penetrating electron radiation on electronic parts and data quality are substantially mitigated through contiguous shielding, filtering of pulse height amplitudes, management of high voltage settings, and careful use of radiation-hard, flight-tested parts. The science goals of UVS are to: 1) explore the atmospheres, plasma interactions, and surfaces of the Galilean satellites; 2) determine the dynamics, chemistry, and vertical structure of Jupiter’s upper atmosphere from equator to pole; and 3) investigate the Jupiter-Io connection by quantifying energy and mass flow in the Io atmosphere, neutral clouds, and torus. Here we present the salient features of the UVS instrument and describe the science we plan to address.

Data Impact of the DMSP F18 SSULI UV Data on the Operational GAIM Model

NASA Astrophysics Data System (ADS)

Dandenault, P. B.; Metzler, C. A.; Nicholas, A. C.; Coker, C.; Budzien, S. A.; Chua, D. H.; Finne, T. T.; Dymond, K.; Walker, P. W.; Schunk, R. W.; Scherliess, L.; Gardner, L. C.

2011-12-01

The Naval Research Laboratory (NRL) has developed five ultraviolet remote sensing instruments for the United States Air Force (USAF) Defense Meteorological Satellite Program (DMSP). The DMSP satellites are launched in a near-polar, sun-synchronous orbit at an altitude of approximately 830 km. Each Special Sensor Ultraviolet Limb Imager (SSULI) instrument measures vertical profiles of the natural airglow radiation from atoms, molecules and ions in the upper atmosphere and ionosphere by viewing the earth's limb within a tangent altitude range of approximately 50 km to 750 km. Limb observations are made from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nm to 170 nm, with 1.8 nm resolution. Data products from SSULI observations include nightglow and dayglow Sensor Data Records (SDRs), as well as Environmental Data Records (EDRs) which contain vertical profiles of electron (Ne) densities, N2, O2, O, O+, and Temperature, hmF2, NmF2 and vertical Total Electron Content (TEC). On October 18, 2009, the third SSULI sensor launched from Vandenberg Air Force Base aboard the DMSP F18 spacecraft. The Calibration and Validation of the F18 instrument has completed and the SSULI program is scheduled to go operational at the Air Force Weather Agency (AFWA) in Fall 2011. The SSULI F18 data are ingested by the Global Assimilation of Ionospheric Measurements (GAIM) space weather model, which was developed by Utah State University and has been used operationally at AFWA since February 2006. A brief overview of the SSULI F18 SDR data assimilation process with GAIM is provided and the impact of the SSULI 1356 Å emission on the GAIM model is examined for spring and summer 2011 nightside data in the low-latitude region.

MAUVE/SWIPE: an imaging instrument concept with multi-angular, -spectral, and -polarized capability for remote sensing of aerosols, ocean color, clouds, and vegetation from space

NASA Astrophysics Data System (ADS)

Frouin, Robert; Deschamps, Pierre-Yves; Rothschild, Richard; Stephan, Edward; Leblanc, Philippe; Duttweiler, Fred; Ghaemi, Tony; Riedi, Jérôme

2006-12-01

The Monitoring Aerosols in the Ultraviolet Experiment (MAUVE) and the Short-Wave Infrared Polarimeter Experiment (SWIPE) instruments have been designed to collect, from a typical sun-synchronous polar orbit at 800 km altitude, global observations of the spectral, polarized, and directional radiance reflected by the earth-atmosphere system for a wide range of applications. Based on the heritage of the POLDER radiometer, the MAUVE/SWIPE instrument concept combines the merits of TOMS for observing in the ultra-violet, MISR for wide field-of-view range, MODIS, for multi-spectral aspects in the visible and near infrared, and the POLDER instrument for polarization. The instruments are camera systems with 2-dimensional detector arrays, allowing a 120-degree field-of-view with adequate ground resolution (i.e., 0.4 or 0.8 km at nadir) from satellite altitude. Multi-angle viewing is achieved by the along-track migration at spacecraft velocity of the 2-dimensional field-of-view. Between the cameras' optical assembly and detector array are two filter wheels, one carrying spectral filters, the other polarizing filters, allowing measurements of the first three Stokes parameters, I. Q, and V, of the incident radiation in 16 spectral bands optimally placed in the interval 350-2200 nm. The spectral range is 350-1050 nm for the MAUVE instrument and 1050-2200 nm for the SWIPE instrument. The radiometric requirements are defined to fully exploit the multi-angular, multi-spectral, and multi-polarized capability of the instruments. These include a wide dynamic range, a signal-to-noise ratio above 500 in all channels at maximum radiance level, i.e., when viewing a surface target of albedo equal to 1, and a noise-equivalent-differential reflectance better than 0.0005 at low signal level for a sun at zenith. To achieve daily global coverage, a pair of MAUVE and SWIPE instruments would be carried by each of two mini-satellites placed on interlaced orbits. The equator crossing time of the two satellites would be adjusted to allow simultaneous observations of the overlapping zone viewed from the two parallel orbits of the twin satellites. Using twin satellites instead of a single satellite would allow measurements in a more complete range of scattering angles. A MAUVE/SWIPE satellite mission would improve significantly the accuracy of ocean color observations from space, and will extend the retrieval of ocean optical properties to the ultra-violet, where they become very sensitive to detritus material and dissolved organic matter. It would also provide a complete description of the scattering and absorption properties of aerosol particles, as well as their size distribution and vertical distribution. Over land, the retrieved bidirectional reflectance function would allow a better classification of terrestrial vegetation and discrimination of surface types. The twin satellite concept, by providing stereoscopic capability, would offer the possibility to analyze the three-dimensional structure and radiative properties of cloud fields.

International Ultraviolet Explorer (IUE)

NASA Technical Reports Server (NTRS)

Boehm, Karl-Heinz

1992-01-01

The observation, data reduction, and interpretation of ultraviolet spectra (obtained with the International Ultraviolet Explorer) of Herbig-Haro objects, stellar jets, and (in a few cases) reflection nebulae in star-forming regions is discussed. Intermediate results have been reported in the required semi-annual reports. The observations for this research were obtained in 23 (US1) IUE shifts. The spectra were taken in the low resolution mode with the large aperture. The following topics were investigated: (1) detection of UV spectra of high excitation Herbig-Haro (HH) objects, identification of emission lines, and a preliminary study of the energy distribution of the ultraviolet continuum; (2) details of the continuum energy distribution of these spectra and their possible interpretation; (3) the properties of the reddening (extinction) of HH objects; (4) the possible time variation of strong emission lines in high excitation HH objects; (5) the ultraviolet emission of low excitation HH objects, especially in the fluorescent lines of the H2 molecule; (6) the ultraviolet emission in the peculiar object HH24; (7) the spatial emission distribution of different lines and different parts of the continuum in different HH objects; and (8) some properties of reflection nebula, in the environment of Herbig-Haro objects. Each topic is discussed.

Galaxy NGC 55

NASA Technical Reports Server (NTRS)

2003-01-01

This image of the nearby edge-on spiral galaxy NGC 55 was taken by Galaxy Evolution Explorer on September 14, 2003, during 2 orbits. This galaxy lies 5.4 million light years from our Milky Way galaxy and is a member of the 'local group' of galaxies that also includes the Andromeda galaxy (M31), the Magellanic clouds, and 40 other galaxies. The spiral disk of NGC 55 is inclined to our line of sight by approximately 80 degrees and so this galaxy looks cigar-shaped. This picture is a combination of Galaxy Evolution Explorer images taken with the far ultraviolet (colored blue) and near ultraviolet detectors, (colored red). The bright blue regions in this image are areas of active star formation detected in the ultraviolet by Galaxy Evolution Explorer. The red stars in this image are foreground stars in our own Milky Way galaxy.

Telescience - Concepts and contributions to the Extreme Ultraviolet Explorer mission

NASA Technical Reports Server (NTRS)

Marchant, Will; Dobson, Carl; Chakrabarti, Supriya; Malina, Roger F.

1987-01-01

It is shown how the contradictory goals of low-cost and fast data turnaround characterizing the Extreme Ultraviolet Explorer (EUVE) mission can be achieved via the early use of telescience style transparent tools and simulations. The use of transparent tools reduces the parallel development of capability while ensuring that valuable prelaunch experience is not lost in the operations phase. Efforts made to upgrade the 'EUVE electronics' simulator are described.

KENNEDY SPACE CENTER, FLA. - Orbital Sciences’ L-1011 aircraft takes off from Cape Canaveral Air Force Station carrying the Pegasus XL rocket/Galaxy Evolution Explorer (GALEX) under its belly. Release of the Pegasus was scheduled for about 8 a.m. over the Atlantic Ocean at an altitude of 39,000 feet at a location approximately 100 nautical miles offshore east-northeast of Cape Canaveral. Spacecraft separation from the Pegasus occurs 11 minutes later. At that time the satellite will be in a circular orbit of 431 statute miles (690 km) at a 29-degree inclination. The GALEX will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

NASA Image and Video Library

2003-04-28

KENNEDY SPACE CENTER, FLA. - Orbital Sciences’ L-1011 aircraft takes off from Cape Canaveral Air Force Station carrying the Pegasus XL rocket/Galaxy Evolution Explorer (GALEX) under its belly. Release of the Pegasus was scheduled for about 8 a.m. over the Atlantic Ocean at an altitude of 39,000 feet at a location approximately 100 nautical miles offshore east-northeast of Cape Canaveral. Spacecraft separation from the Pegasus occurs 11 minutes later. At that time the satellite will be in a circular orbit of 431 statute miles (690 km) at a 29-degree inclination. The GALEX will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

STS-67 crew insignia

NASA Technical Reports Server (NTRS)

1995-01-01

Observation and remote exploration of the Universe in the ultraviolet wavelengths of light are the focus of the STS-67/ASTRO-2 mission, as depicted in the crew patch designed by the crew members. The insignia shows the ASTRO-2 telescopes in the Space Shuttle Endeavour's payload bay, orbiting high above Earth's atmosphere. The three sets of rays, diverging from the telescope on the patch atop the Instrument Pointing System (IPS), correspond to the three ASTRO-2 telescopes - the Hopkins Ultraviolet Telescope (HUT), The Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE). The telescopes are coaligned to simultaneously view the same astronomical object, as shown by the convergence of rays on the NASA symbol. This symbol also represents the excellence of the union of the NASA teams and the universality's in the exploration of the universe through astronomy. The celestial targets of ASTRO-2 include the observation of planets, stars and gala

Recent solar extreme ultraviolet irradiance observations and modeling: A review

NASA Technical Reports Server (NTRS)

Tobiska, W. Kent

1993-01-01

For more than 90 years, solar extreme ultraviolet (EUV) irradiance modeling has progressed from empirical blackbody radiation formulations, through fudge factors, to typically measured irradiances and reference spectra was well as time-dependent empirical models representing continua and line emissions. A summary of recent EUV measurements by five rockets and three satellites during the 1980s is presented along with the major modeling efforts. The most significant reference spectra are reviewed and threee independently derived empirical models are described. These include Hinteregger's 1981 SERF1, Nusinov's 1984 two-component, and Tobiska's 1990/1991/SERF2/EUV91 flux models. They each provide daily full-disk broad spectrum flux values from 2 to 105 nm at 1 AU. All the models depend to one degree or another on the long time series of the Atmosphere Explorer E (AE-E) EUV database. Each model uses ground- and/or space-based proxies to create emissions from solar atmospheric regions. Future challenges in EUV modeling are summarized including the basic requirements of models, the task of incorporating new observations and theory into the models, the task of comparing models with solar-terrestrial data sets, and long-term goals and modeling objectives. By the late 1990s, empirical models will potentially be improved through the use of proposed solar EUV irradiance measurements and images at selected wavelengths that will greatly enhance modeling and predictive capabilities.

Time-resolved FUSE photometric and spectroscopic observations: PG 1219+534, PG 1605+072, and PG 1613+426

NASA Astrophysics Data System (ADS)

Kuassivi; Bonanno, A.; Ferlet, R.

2005-11-01

We report the detection of pulsations in the far ultraviolet (FUV) light curves of PG 1219+534, PG 1605+072 and PG 1613+426 obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) in time tagged mode (TTAG). Exposures of the order of a few ksec were sufficient to observe the main frequencies of PG 1219+534 and PG 1605+072 and confirm the detection of a pulsation mode at the surface of PG 1613+426 as reported from ground. For the first time we derive time resolved spectroscopic FUSE data of a sdB pulsator (PG 1605+072) and comment on its line profile variation diagram (lpv diagram). We observe the phase shift between the maximum luminosity and the maximum radius to be consistent with the model of an adiabatic pulsator. We also present evidence that the line broadening previously reported is not caused by rotation but is rather an observational bias due to the rapid Doppler shift of the lines with 17 km s-1 amplitude. Thus our observations do not support the previous claim that PG 1605+072 is (or will evolve into) an unusually fast rotating degenerate dwarf. These results demonstrate the asteroseismological potential of the FUSE satellite which should be viewed as another powerful means of investigating stellar pulsations, along with the MOST and COROT missions.

Anomalous meridional thermospheric neutral winds in the AE-E NATE data: Effects of the equatorial nighttime pressure bulge

NASA Technical Reports Server (NTRS)

Goembel, L.; Herrero, F. A.

1995-01-01

The work described here makes it possible to identify anomalous wind behavior such as the nighttime meridional wind abatements that occur at F-region heights. A new analysis technique uses a simple empirical wind model to simulate measurements of 'normal' winds (as measured by the Neutral Atmosphere and Temperature Experiment (NATE) that flew on the Atmosphere Explorer-E (AE-E)) to highlight anomalous wind measurements made by the satellite while in circular orbits at 270-290 km altitude. Our approach is based on the recognition that the 'in orbit' wind variation must show the combined effects of the diurnal wind variation as seen from the ground with the latitude variation of the satellite orbit. For the data period 77250-78035 examined thus far, the wind abatement always occurred with a corresponding pressure or temperature maximum, and was detected on 12 out of the 36 nights with data. This study has revealed that the wind abatement occur only during or shortly after increases in solar extreme ultraviolet (EUV) flux, as indicated by daily radio flux measurements. In the past, nighttime wind reversals at mid-latitudes have been associated with increased geomagnetic activity. This study indicates that intensified solar EUV heating may be responsible for anomalous thermospheric nighttime winds at mid-latitudes.

Hello to Arms

NASA Technical Reports Server (NTRS)

2005-01-01

This image highlights the hidden spiral arms (blue) that were discovered around the nearby galaxy NGC 4625 by the ultraviolet eyes of NASA's Galaxy Evolution Explorer.

The image is composed of ultraviolet and visible-light data, from the Galaxy Evolution Explorer and the California Institute of Technology's Digitized Sky Survey, respectively. Near-ultraviolet light is colored green; far-ultraviolet light is colored blue; and optical light is colored red.

As the image demonstrates, the lengthy spiral arms are nearly invisible when viewed in optical light while bright in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light.

The youthful arms are also very long, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far.

Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own.

The armless companion galaxy seen below NGC 4625 is called NGC 4618. Astronomers do not know why it lacks arms but speculate that it may have triggered the development of arms in NGC 4625.

Invest in sunblock

NASA Astrophysics Data System (ADS)

Carlowicz, Michael

According to data gathered by the Total Ozone Mapping Spectrometer (TOMS) on NASA's Nimbus-7 satellite, the amount of ultraviolet radiation reaching the surface of Earth from the Sun has increased as the total amount of ozone in the atmosphere has decreased over the past 15 years.“The increases are largest in the middle and high latitudes, where most people live and most of the world's agricultural activity occurs,” said Jay Herman, an atmospheric scientist at NASA's Goddard Space Flight Center. According to Herman and colleagues, since 1978 the average annual exposure to ultraviolet B radiation (in the 290-320-nm range) has increased by 6.8% per decade at 55°N latitude, crossing the United Kingdom, Germany, Scandinavia, and Russia. At 55°S, cutting across southern Argentina and Chile, ultraviolet exposure increased 9.8% per decade. The change in UV-B radiation in most of North America was about 4% per decade.

Increased exposure of Southern Ocean phytoplankton to ultraviolet radiation

NASA Astrophysics Data System (ADS)

Lubin, Dan; Arrigo, Kevin R.; van Dijken, Gert L.

2004-05-01

Satellite remote sensing of both surface solar ultraviolet radiation (UVR) and chlorophyll over two decades shows that biologically significant ultraviolet radiation increases began to occur over the Southern Ocean three years before the ozone ``hole'' was discovered. Beginning in October 1983, the most frequent occurrences of enhanced UVR over phytoplankton-rich waters occurred in the Weddell Sea and Indian Ocean sectors of the Southern Ocean, impacting 60% of the surface biomass by the late 1990s. These results suggest two reasons why more serious impacts to the base of the marine food web may not have been detected by field experiments: (1) the onset of UVR increases several years before dedicated field work began may have impacted the most sensitive organisms long before such damage could be detected, and (2) most biological field work has so far not taken place in Antarctic waters most extensively subjected to enhanced UVR.

Ultraviolet colors of W Ursae Majoris - Gravity darkening, temperature differences, and the cause of W-type light curves

NASA Technical Reports Server (NTRS)

Eaton, J. A.; Wu, C.-C.; Rucinski, S. M.

1980-01-01

The paper presents photometry of the prototype W UMa binary system in three ultraviolet bands with the ANS satellite. It was found that W UMa has low-gravity darkening beta of 0.03; that temperature differences between the components not established by gravity darkening are insignificant; and that the bolometric albedo is not very large. It was also found that W UMa is limb-darkened in the ultraviolet region, and that the inner hemisphere of the less massive component is hotter than that predicted by gravity darkening and the reflection effect. It was concluded that about 20% of the surface area of the component responsible for large gravity darkening is covered by dark spots distributed uniformly in the longitudinal direction. An observational value of the convective darkening exponent of 0.054 plus or minus 0.02 is proposed.

User's guide to the Nimbus-4 backscatter ultraviolet experiment data sets

NASA Technical Reports Server (NTRS)

Lowrey, B. E.

1978-01-01

The first year's data from the Nimbus 4 backscatter ultraviolet (BUV) experiment have been archived in the National Space Science Data Center (NSSDC). Backscattered radiances in the ultraviolet measured by the satellite were used to compute the global total ozone for the period April 1970 - April 1971. The data sets now in the NSSDC are the results obtained by the Ozone Processing Team, which has processed the data with the purpose of determining the best quality of the data. There are four basic sets of data available in the NSSDC representing various stages in processing. The primary data base contains organized and cleaned data in telemetry units. The radiance data has had most of the engineering calibrations performed. The detailed total ozone data is the result of computations to obtain the total ozone; the Compressed Total Ozone data is a convenient condensation of the detailed total ozone. Product data sets are also included.

Ultraviolet Photometric Parameters of the Icy Galilean Satellites

NASA Technical Reports Server (NTRS)

Hendrix, Amanda R.; Domingue, Deborah L.; King, Kimberly

2002-01-01

The Galilean satellites are each phase-locked with Jupiter, so that one hemisphere (the Jovian hemisphere centered on 0 deg longitude) is always facing Jupiter. The leading hemisphere is centered on 90 deg W longitude, while the central longitude of the trailing hemisphere is 270 deg W. Because Jupiter's magnetosphere corotates at a rate faster than the orbital speed of the moons, the satellites' trailing hemispheres are affected by magnetospheric particle bombardment. Some effects are implantation of magnetospheric ions, sputtering, erosion and grain size alteration. The leading hemispheres of these moons are more dominantly affected by micrometeorite bombardment, while the Jovian hemispheres may be affected by dust and/or neutral wind particles streaming out radially from Io and its torus.

Galaxy NGC 55

NASA Image and Video Library

2003-12-10

This image of the nearby edge-on spiral galaxy NGC 55 was taken by Galaxy Evolution Explorer on September 14, 2003, during 2 orbits. This galaxy lies 5.4 million light years from our Milky Way galaxy and is a member of the "local group" of galaxies that also includes the Andromeda galaxy (M31), the Magellanic clouds, and 40 other galaxies. The spiral disk of NGC 55 is inclined to our line of sight by approximately 80 degrees and so this galaxy looks cigar-shaped. This picture is a combination of Galaxy Evolution Explorer images taken with the far ultraviolet (colored blue) and near ultraviolet detectors, (colored red). The bright blue regions in this image are areas of active star formation detected in the ultraviolet by Galaxy Evolution Explorer. The red stars in this image are foreground stars in our own Milky Way galaxy. http://photojournal.jpl.nasa.gov/catalog/PIA04923

International Ultraviolet Explorer Observatory operations

NASA Technical Reports Server (NTRS)

1985-01-01

This volume contains the final report for the International Ultraviolet Explorer IUE Observatory Operations contract. The fundamental operational objective of the International Ultraviolet Explorer (IUE) program is to translate competitively selected observing programs into IUE observations, to reduce these observations into meaningful scientific data, and then to present these data to the Guest Observer in a form amenable to the pursuit of scientific research. The IUE Observatory is the key to this objective since it is the central control and support facility for all science operations functions within the IUE Project. In carrying out the operation of this facility, a number of complex functions were provided beginning with telescope scheduling and operation, proceeding to data processing, and ending with data distribution and scientific data analysis. In support of these critical-path functions, a number of other significant activities were also provided, including scientific instrument calibration, systems analysis, and software support. Routine activities have been summarized briefly whenever possible.

Left Limb of North Pole of the Sun, March 20, 2007 (Anaglyph)

NASA Technical Reports Server (NTRS)

2007-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Left eye view of a stereo pair Click on the image for full resolution TIFF Figure 2: Right eye view of a stereo pair Click on the image for full resolution TIFF Figure 1: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-B spacecraft. STEREO-B is located behind the Earth, and follows the Earth in orbit around the Sun. This location enables us to view the Sun from the position of a virtual left eye in space. Figure 2: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-A spacecraft. STEREO-A is located ahead of the Earth, and leads the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual right eye in space.

NASA's Solar TErrestrial RElations Observatory (STEREO) satellites have provided the first three-dimensional images of the Sun. For the first time, scientists will be able to see structures in the Sun's atmosphere in three dimensions. The new view will greatly aid scientists' ability to understand solar physics and thereby improve space weather forecasting.

This image is a composite of left and right eye color image pairs taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-B and STEREO-A spacecraft. STEREO-B is located behind the Earth, and follows the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual left eye in space. STEREO-A is located ahead of the Earth, and leads the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual right eye in space.

The EUVI imager is sensitive to wavelengths of light in the extreme ultraviolet portion of the spectrum. EUVI bands at wavelengths of 304, 171 and 195 Angstroms have been mapped to the red blue and green visible portion of the spectrum; and processed to emphasize the three-dimensional structure of the solar material.

STEREO, a two-year mission, launched October 2006, will provide a unique and revolutionary view of the Sun-Earth System. The two nearly identical observatories -- one ahead of Earth in its orbit, the other trailing behind -- will trace the flow of energy and matter from the Sun to Earth. They will reveal the 3D structure of coronal mass ejections; violent eruptions of matter from the sun that can disrupt satellites and power grids, and help us understand why they happen. STEREO will become a key addition to the fleet of space weather detection satellites by providing more accurate alerts for the arrival time of Earth-directed solar ejections with its unique side-viewing perspective.

STEREO is the third mission in NASA's Solar Terrestrial Probes program within NASA's Science Mission Directorate, Washington. The Goddard Science and Exploration Directorate manages the mission, instruments, and science center. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., designed and built the spacecraft and is responsible for mission operations. The imaging and particle detecting instruments were designed and built by scientific institutions in the U.S., UK, France, Germany, Belgium, Netherlands, and Switzerland. JPL is a division of the California Institute of Technology in Pasadena.

Heavy ions in Jupiter's environment

NASA Technical Reports Server (NTRS)

Brown, R. A.

1980-01-01

The extended atmosphere of the Jupiter system consists of atoms and ions of heavy elements. This material originates on the satellite Io. Energy is lost from the thermal plasma in collisionally excited optical and ultraviolet emission. The juxtaposition of Earth and spacecraft measurements provide insight concerning the underlying processes of particle transport and energy supply.

First Look at the Upper Tropospheric Ozone Mixing Ratio from OMI Estimated using the Cloud Slicing Technique

NASA Technical Reports Server (NTRS)

Bhartia, Pawan K.; Ziemke, Jerry; Chandra, Sushil; Joiner, Joanna; Vassilkov, Alexandra; Taylor, Steven; Yang, Kai; Ahn, Chang-Woo

2004-01-01

The Cloud Slicing technique has emerged as a powerful tool for the study of ozone in the upper troposphere. In this technique one looks at the variation with cloud height of the above-cloud column ozone derived from the backscattered ultraviolet instruments, such as TOMS, to determine the ozone mixing ratio. For this technique to work properly one needs an instrument with relatively good horizontal resolution with very good signal to noise in measuring above-cloud column ozone. In addition, one needs the (radiatively) effective cloud pressure rather than the cloud-top pressure, for the ultraviolet photons received by a satellite instrument are scattered from inside the cloud rather than from the top. For this study we use data from the OMI sensor, which was recently launched on the EOS Aura satellite. OMI is a W-Visible backscattering instrument with a nadir pixel size of 13 x 24 km. The effective cloud pressure is derived from a new algorithm based on Rotational Raman Scattering and O2-O2, absorption in the 340-400 nm band of OMI.

Ozone determinations with the NOAA SBUV/2 system

NASA Technical Reports Server (NTRS)

Planet, Walter G.; Lienesch, James H.; Bowman, Harold D.; Miller, Alvin J.; Nagatani, Ronald M.

1994-01-01

The NOAA satellite ozone monitoring program was initiated by the National Environmental Satellite Data and Information Service (NESDIS) in December 1984, with the launch of the NOAA-9 spacecraft carrying the first operational Solar Backscatter Ultraviolet Spectrometer (SBUV/2). This instrument and its successor on NOAA-11, launched in 1988, are similar to the SBUV instrument launched by the NASA in 1978 on the Nimbus-7 research spacecraft. Measurements by the SBUV and SBUV/2 instruments overlap beginning in 1985. These instruments use measurements of the reflected ultraviolet solar radiation from the atmosphere to derive total ozone amounts and ozone vertical profiles. Since launch, the NOAA instruments and the derived products have been undergoing extensive evaluation by scientists of NOAA and NASA. Measurements obtained with these instruments are processed in real time by the NESDIS. These are reprocessed as the SBUV/2 instrument characterization is refined and as the retrieval algorithm for processing the data is improved. The NOAA-9 ozone data archive begins in March 1985 and continues through October 1990. The archive of NOAA-11 data begins in January 1989 and the data continues to be acquired in 1992.

Satellite measurements of the backscattered ultraviolet to determine ozone trends, volcanic SO2, and nitric oxide

NASA Technical Reports Server (NTRS)

Mcpeters, Richard

1993-01-01

Measurements of the atmospheric backscattered UV albedo have been used from satellites for more than 20 years to measure ozone. The longest continuous record has been from the Solar Backscattered Ultraviolet instrument (SBUV) and TOMS on the Nimbus 7 satellite, which have been in operation since November of 1978. Because of degradation in space of the diffuser plate used to measure extraterrestrial solar flux, it has been necessary to develop new techniques to maintain the calibration of these instruments. Calibration is maintained by requiring that ozone measured by different wavelength pairs be consistent, and by requiring that ozone measured at different solar zenith angles be consistent. This technique of using a geophysical quantity, ozone, as a transfer standard for wavelength calibration is very powerful. The recalibrated data have been used to measure total ozone trends to an accuracy of +/- 1.3 percent 2(sigma) error over ten years. No significant trends are found near the equator, but significant trends larger than predicted by homogeneous chemistry are found at middle to high latitudes in both hemispheres. In addition, UV albedo data have been used to measure SO2 using band structure in the 300-310 nm range, and to measure nitric oxide in the upper stratosphere and mesosphere using the (10) and (02) NO gamma band fluorescence features.

GALEX 1st Light Far Ultraviolet

NASA Image and Video Library

2003-05-28

This image was taken May 21 and 22, 2003 by NASA Galaxy Evolution Explorer. The image was made from data gathered by the far ultraviolet channel of the spacecraft camera during the mission first light milestone. It shows about 400 celestial objects

Validation and in vivo assessment of an innovative satellite-based solar UV dosimeter for a mobile app dedicated to skin health.

PubMed

Morelli, M; Masini, A; Simeone, E; Khazova, M

2016-08-31

We present an innovative satellite-based solar UV (ultraviolet) radiation dosimeter with a mobile app interface that has been validated by exploiting both ground-based measurements and an in vivo assessment of the erythemal effects on some volunteers having controlled exposure to solar radiation. The app with this satellite-based UV dosimeter also includes other related functionalities such as the provision of safe sun exposure time updated in real-time and end exposure visual/sound alert. Both validations showed that the system has a good accuracy and reliability needed for health-related applications. This app will be launched on the market by siHealth Ltd in May 2016 under the name of "HappySun" and is available for both Android and iOS devices (more info on ). Extensive R&D activities are on-going for the further improvement of the satellite-based UV dosimeter's accuracy.

Science Operations of the International Ultraviolet Explorer (IUE) Observatory

NASA Technical Reports Server (NTRS)

1996-01-01

The fundamental operational objective of the International Ultraviolet Explorer (IUE) program is to support competitively selected astronomical research program. Through the IUE program, researchers make IUE observations, have their scientific data reduced in a meaningful way, and receive data products in a form amenable to the pursuit of scientific research. The IUE Observatory is key to the program since it is the central control and support facility for all science support functions within the IUE project.

The effect of surface anisotropy on the accuracy of total ozone estimates from satellite observations

NASA Technical Reports Server (NTRS)

Fraser, R. S.; Ahmad, Z.

1978-01-01

The total amount of ozone in a vertical column of the earth's atmosphere is being derived from satellite measurements of the intensity of ultraviolet sunlight scattered by the earth-atmosphere system. The algorithm for deriving the ozone amount utilizes the assumption that the earth's surface reflects the incident light isotropically according to Lambert's law. Natural surface reflection deviates more or less from this law. Two extreme examples of anisotropic reflection from dark ocean and from bright snow are analyzed by means of models for their effects on the derived values of ozone.

New approaches to removing cloud shadows and evaluating the 380 nm surface reflectance for improved aerosol optical thickness retrievals from the GOSAT/TANSO-Cloud and Aerosol Imager

NASA Astrophysics Data System (ADS)

Fukuda, Satoru; Nakajima, Teruyuki; Takenaka, Hideaki; Higurashi, Akiko; Kikuchi, Nobuyuki; Nakajima, Takashi Y.; Ishida, Haruma

2013-12-01

satellite aerosol retrieval algorithm was developed to utilize a near-ultraviolet band of the Greenhouse gases Observing SATellite/Thermal And Near infrared Sensor for carbon Observation (GOSAT/TANSO)-Cloud and Aerosol Imager (CAI). At near-ultraviolet wavelengths, the surface reflectance over land is smaller than that at visible wavelengths. Therefore, it is thought possible to reduce retrieval error by using the near-ultraviolet spectral region. In the present study, we first developed a cloud shadow detection algorithm that uses first and second minimum reflectances of 380 nm and 680 nm based on the difference in Rayleigh scattering contribution for these two bands. Then, we developed a new surface reflectance correction algorithm, the modified Kaufman method, which uses minimum reflectance data at 680 nm and the NDVI to estimate the surface reflectance at 380 nm. This algorithm was found to be particularly effective at reducing the aerosol effect remaining in the 380 nm minimum reflectance; this effect has previously proven difficult to remove owing to the infrequent sampling rate associated with the three-day recursion period of GOSAT and the narrow CAI swath of 1000 km. Finally, we applied these two algorithms to retrieve aerosol optical thicknesses over a land area. Our results exhibited better agreement with sun-sky radiometer observations than results obtained using a simple surface reflectance correction technique using minimum radiances.

ULTRAVIOLET RADIATION AND ARSENIC INTERACTIONS: EFFECTS ON CLADOCERANS

EPA Science Inventory

The effects of arsenic and ultraviolet radiation (UV) on cladocerans have been examined separately, however the interaction of these two stresses has not been explored. Potential synergism between these two stresses is possible as arsenic is known to inhibit repair of UV induced ...

Left Limb of North Pole of the Sun, March 20, 2007

NASA Technical Reports Server (NTRS)

2007-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1: Left eye view of a stereo pair Click on the image for full resolution TIFF Figure 2: Right eye view of a stereo pair Click on the image for full resolution TIFF Figure 1: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-B spacecraft. STEREO-B is located behind the Earth, and follows the Earth in orbit around the Sun. This location enables us to view the Sun from the position of a virtual left eye in space. Figure 2: This image was taken by the SECCHI Extreme UltraViolet Imager (EUVI) mounted on the STEREO-A spacecraft. STEREO-A is located ahead of the Earth, and leads the Earth in orbit around the Sun, This location enables us to view the Sun from the position of a virtual right eye in space.

NASA's Solar TErrestrial RElations Observatory (STEREO) satellites have provided the first three-dimensional images of the Sun. For the first time, scientists will be able to see structures in the Sun's atmosphere in three dimensions. The new view will greatly aid scientists' ability to understand solar physics and thereby improve space weather forecasting.

The EUVI imager is sensitive to wavelengths of light in the extreme ultraviolet portion of the spectrum. EUVI bands at wavelengths of 304, 171 and 195 Angstroms have been mapped to the red blue and green visible portion of the spectrum; and processed to emphasize the temperature difference of the solar material.

STEREO, a two-year mission, launched October 2006, will provide a unique and revolutionary view of the Sun-Earth System. The two nearly identical observatories -- one ahead of Earth in its orbit, the other trailing behind -- will trace the flow of energy and matter from the Sun to Earth. They will reveal the 3D structure of coronal mass ejections; violent eruptions of matter from the sun that can disrupt satellites and power grids, and help us understand why they happen. STEREO will become a key addition to the fleet of space weather detection satellites by providing more accurate alerts for the arrival time of Earth-directed solar ejections with its unique side-viewing perspective.

STEREO is the third mission in NASA's Solar Terrestrial Probes program within NASA's Science Mission Directorate, Washington. The Goddard Science and Exploration Directorate manages the mission, instruments, and science center. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., designed and built the spacecraft and is responsible for mission operations. The imaging and particle detecting instruments were designed and built by scientific institutions in the U.S., UK, France, Germany, Belgium, Netherlands, and Switzerland. JPL is a division of the California Institute of Technology in Pasadena.

Satellite to measure equatorial ozone layer

NASA Technical Reports Server (NTRS)

1975-01-01

The Atmosphere Explorer E (Explorer 55) Satellite is described. The satellite will gather information on the earth's upper atmosphere, particularly regarding the condition of the protective ozone layer. The satellite will also provide information concerning the earth's heat balance, and heat flow characteristics, and energy conversion mechanisms.

IUE's treasure-chest of the ultraviolet Universe

NASA Astrophysics Data System (ADS)

1997-11-01

IUE was the most long-lived and (by a wide margin) the most productive satellite so far, in the history of space astronomy. After going into orbit on 26 January 1978, as a NASA-ESA-UK project, IUE was meant to operate for three years. More than eighteen years later, IUE still worked 24 hours a day, harvesting new knowledge for astronomers. The last observations were made from ESA's ground station at Villafranca, Spain, on 26 September 1996, and IUE was switched off four days later. Since then, team members at Villafranca and at NASAs Goddard Space Flight Center have used modern data-processing and information technology to recycle 100,000 ultraviolet spectra of comets, planets, stars, galaxies and quasars, acquired by IUE during its 18.5 years of operations. As a result, the IUE Final Archive is already available on-line via the Internet to hundreds of users who have registered to work with the data. The last few items (about 2 per cent of the total) will be added before the end of November. Also to be presented at the Sevilla conference is ESA's system called INES ("IUE Newly Extracted Spectra") which offers access, selection and distribution of data products, in a thoroughly user-friendly fashion. The IUE Final Archive is the third massive compendium made available to the worlds astronomers by ESA in 1997. The Hipparcos and Tycho Catalogues, released earlier in the year, give the positions of stars with unprecedented accuracy, thanks to ESA's Hipparcos satellite. "Space astronomy has set the example in providing a high standard of data quality and making the data accessible to the scientific community through archives", says Roger Bonnet, ESA's Scientific Director. "Now, ground-based observatories are following suit. The data legacy of IUE will be distributed to he community so that research on IUE data can continue long after the end of IUE's lifetime in space". Wonders of ultraviolet spectroscopy IUE analysed ultraviolet light, in a wavelength range from 1150 to 3200 angstrom units, which is blotted out by the Earths atmosphere. Operating far above the atmosphere, IUE generated spectra showing intensities at different wavelengths, coming from the selected objects in the sky. To an astrophysicist, such spectra are much more informative than images, about the mechanisms that produce and dissipate the objects energy. Temperatures, motions, magnetism and chemical composition are all discernable in the ultraviolet spectra. As a result, astronomers have a far better picture of the hot atmospheres of stars than they did before IUE's launch. Even the Sun, a quiet star of moderate size, possesses a very hot atmosphere emitting ultraviolet light, which is now being monitored non-stop by the ESA-NASA solar spacecraft SOHO. Some other stars, ranging from small white dwarfs to large, massive stars, give off ultraviolet emissions from their very hot surfaces. Hot and fierce winds of gas emitted from stars have a profound effect on the lives and environments of the stars, and on any companions caught up in the winds. IUE unmasked the ultraviolet behaviour of a large menagerie of different star types, and astronomers at the Sevilla meeting will discuss profound revisions in astrophysical ideas resulting from the observations. Other participants will review IUE's contribution to new knowledge about galaxies. These vast assemblies of stars also reveal violent behaviour in ultraviolet light. In a special campaign, a multinational team used IUE to observe the stormy galaxy NGC 5548 some 60 times in eight months. As a result, they discovered effects of central outbursts spreading from hot regions at the very core of the galaxy to adjacent cooler regions, in a timescale of weeks. In galaxy NGC 7469, observed simultaneously by IUE and by the X-ray satellite Rossi XTE, the timescale shrank to days. Quasars are erupting galaxies observable at great distances, and their examination by ultraviolet light, by IUE and more recently by the Hubble Space Telescope, give special clues to the nature of the gas in the almost empty spaces between galaxies, and to the manufacture of the chemical elements within the galaxies. The quasar studies to be reviewed at Sevilla already occupy an important place in the efforts to understand the character and evolution of the Universe at large. The ultraviolet data on element-making suggest that massive stars, far bigger than the Sun, were more numerous when the galaxies were young. Advantages of a long life The sheer durability of IUE enabled astronomers to revisit many objects over nearly two decades and to see changes occurring with them. The prolonged study of the black hole in 3C390.3 was a case in point. Another conspicuous example of the advantages of a long life concerns Supernova 1987A. This star was seen exploding in a nearby galaxy, the Large Magellanic Cloud, half-way through IUEs operational life. IUE was the first space telescope to be turned towards Supernova 1987A. It revealed precisely which star had blown up, identified chemical elements in the debris, and discovered a pre-existing ring of gas and dust surrounding the star. IUE continued observing Supernova 1987A at intervals over nine years, so providing a unique chronicle of the early evolution of a supernova remnant. Lesser stellar outbursts called novae have also provided frequent "targets of opportunity" for IUE. The return of Halleys Comet in 1985-86 was a long anticipated event, and the ultraviolet observations by IUE measured the rate at which the famous object spewed water vapour into space. But many comets appear unexpectedly, and IUE was able to examine them too, from Comet Seargent in 1978 to Comet Hale-Bopp in 1986. Astronomers have built up a comprehensive picture of comets seen by ultraviolet light at different stages of their evolution, and at different distances from the Sun. As a result, they have a much better understanding of how comets react and change during their rare visits to the vicinity of the Sun and the Earth. IUEs long life also enabled it to observe rare and serendipitous events. The satellite was already more than sixteen years old when Comet Shoemaker-Levy 9 hit Jupiter in July 1994. The event was well anticipated, so IUE was able first to study Jupiter in a normal state, and then to see the changes in the ultraviolet spectra during and after the impacts of the comet fragments. The astronomers favourite satellite Operational and scientific statistics about IUE are remarkable. The satellites observations have resulted in more than 3600 scientific papers published by 3000 astronomers from 25 countries. In addition, about 500 doctoral theses using IUE data show the educational value of IUE in universities all over the world. Amateur astronomers have also shown a remarkable degree of interest in IUE results, which provide them with a valuable and important link between their activities and those of professional astronomers. "Although IUE never had the popular appeal of the Hubble Space Telescope, it was always the professional astronomers favourite satellite," remarks Willem Wamsteker, the Dutch astronomer who is ESA's project manager for IUE. "They could visit Villafranca or Goddard and supervise the operations, just as if they were at an observatory on the ground. Towards the end, they could make their observations remotely, without leaving their institutes. Historians of astronomy may well credit IUE with the big change in professional habits which made space observatories a tool, not just for a few hardware-minded specialists, but for all astronomers." The meeting in Sevilla will end on 14 November with a review of the prospects for new space missions for ultraviolet astronomy. The Hubble Space Telescope and some Space Shuttle missions offer limited opportunities for ultraviolet spectroscopy. So will ESA's XMM X-ray mission. The only confirmed mission fully dedicated to the ultraviolet region is NASA's FUSE spacecraft, due to be launched in the year 2000, with rather limited scope and duration. Astronomers in developing countries have been persuaded by experience with IUE that they too can participate in spaceborne observations without emigrating. ESA has helped to foster this ambition. A UN-ESA workshop in Sri Lanka in 1996 recommended the creation of a World Space Observatory, and this will be cited at the Sevilla meeting in the context of possible future facilities for ultraviolet astronomy. Meanwhile IUE will not be easy to replace. No authorized mission yet in sight will combine a wide spectral range with great flexibility of operation. Current astronomical campaigns, ranging from studies of auroras in planets to the efforts to understand the spectacular yet mysterious gamma-ray bursts far away in the cosmos, already miss the input from IUE. The astronomers sense of loss should be seen positively, as a tribute to IUEs achievements when it dominated ultraviolet space astronomy for nearly two decades.

Early Rockets

NASA Image and Video Library

1959-10-21

This image is a cutaway illustration of the Explorer I satellite with callouts. The Explorer I satellite was America's first scientific satellite launched aboard the Jupiter C launch vehicle on January 31, 1958. The Explorer I carried the radiation detection experiment designed by Dr. James Van Allen and discovered the Van Allen Radiation Belt.

Prospects for Near Ultraviolet Astronomical Observations from the Lunar Surface — LUCI

NASA Astrophysics Data System (ADS)

Mathew, J.; Kumar, B.; Sarpotdar, M.; Suresh, A.; Nirmal, K.; Sreejith, A. G.; Safonova, M.; Murthy, J.; Brosch, N.

2018-04-01

We have explored the prospects for UV observations from the lunar surface and developed a UV telescope (LUCI-Lunar Ultraviolet Cosmic Imager) to put on the Moon, with the aim to detect bright UV transients such as SNe, novae, TDE, etc.

Observations of solar active regions and solar flares by OSO-7

NASA Technical Reports Server (NTRS)

Neupert, W. M.

1977-01-01

Contributions made to the physics of coronal active regions and flares by the extreme ultraviolet and soft X-ray spectroheliograph on OSO-7 were discussed. Coronal structures above active regions were discussed from the point of view of their morphology and physical properties, including their relationship to photospheric and coronal magnetic fields. OSO-7 also recorded flares with sufficient spatial and temporal resolution to record, in some instances for the first time, the extreme ultraviolet and soft X-ray emission associated with such chromospheric phenomena as filament activation and the emergence of satellite sunspots. Flare phenomena were reviewed in terms of the several stages of evolution typically associated with the event.

ARC-1989-AC89-7032

NASA Image and Video Library

1989-08-24

Range : 530,000 km (330,000 mi.) This color photo of Neptune's large satellite Triton has a resolution of about 10 km (6.2 mi), sufficient to begin to show topographic detail. The image was made from pictures taken through the green, violet and ultraviolet filters. In this technique, regions that are highly reflective in the ultraviolet appear blue in color. In reality, there is no part of Triton that would appear blue to the eye. The bright southern hemisphere of Triton, which fills most of this frame, is generally pink in tone as is the even brighter equatorial band. The darker regions north of the equator also tend to be pink or reddish in color.

Drawing of STS-34 SSBUV orbiter interface and command and status monitoring

NASA Technical Reports Server (NTRS)

1989-01-01

Line drawing titled SSBUV ORBITER INTERFACE FOR COMMAND AND STATUS MONITORING shows how the shuttle solar backscatter ultraviolet (UV) (SSBUV) will be operated by crewmembers on the aft flight deck using a autonomous payload controller (APC). SSBUV instrument will calibrate ozone measuring space-based instruments on the National Oceanic and Atmospheric Administration's (NOAA's) TIROS satellites NOAA-9 and NOAA-11. During STS-34, SSBUV instruments mounted in get away special (GAS) canisters in Atlantis', Orbiter Vehicle (OV) 104's, payload bay will use the Space Shuttle's orbital flight path to assess instrument performance by directly comparing data from identical instruments aboard the TIROS satellite, as OV-104 and the satellite pass over the same Earth location within a one-hour window. SSBUV is managed by NASA's Goddard Space Flight Center (GSFC).

Results from the calibration of the Extreme Ultraviolet Explorer instruments

NASA Technical Reports Server (NTRS)

Welsh, Barry Y.; Jelinsky, Pat; Vedder, Peter W.; Vallerga, John V.; Finley, David S.; Malina, Roger F.

1991-01-01

The paper describes the main features and selected results of the calibration of the scientific instruments to be flown on the Extreme Ultraviolet Explorer in 1991. The instrument payload includes three grazing incidence scanning telescopes and an EUV spectrometer/deep survey instrument covering the spectral region 70-800 A. The measured imaging characteristics, the effective areas, and the details of spectral responses of the instruments are presented. Diagrams of the cross-sectional views of the scanning telescope and the deep-survey/spectrometer telescope are included.

The extreme ultraviolet explorer mission

NASA Technical Reports Server (NTRS)

Malina, R. F.; Bowyer, S.

1988-01-01

The science design goals and engineering implementation for the Extreme Ultraviolet Explorer (EUVE) science payload are discussed. The primary scientific goal of the EUVE payload is to carry out an all-sky survey in the 100- to 900-A band of the spectrum. Another goal of the mission is to demonstrate the use of a scientific platform in near-earth orbit. EUVE data will be used to study the distribution of EUV stars in the neighborhood of the sun and the emission physics responsible for the EUV mission.

Nitrogen dioxide observations from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument: Retrieval algorithm and measurements during DISCOVER-AQ Texas 2013

EPA Science Inventory

The Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) airborne instrument is a test bed for upcoming air quality satellite instruments that will measure backscattered ultraviolet, visible and near-infrared light from geostationary orbit. GeoTASO flew on the NASA F...

Multi-Wavelength investigation of the co-orbital moons Dione and Helene

NASA Astrophysics Data System (ADS)

Royer, Emilie M.; Hendrix, Amanda R.; Howett, Carly; Spilker, Linda

2017-10-01

The icy satellites Dione and Helene share the same orbit, at 6.26 Saturn radii from the giant planet, which is within Saturn’s diffuse E ring. Helene is one of Dione’s two Trojan moons, located in the leading Lagrangian point L4 of Dione’s orbit. We present here preliminary results on the investigation of the Dione-Helene duo in term of origin, formation and evolution. Specifically, the key objectives are to retrieve the photometric properties and composition of the moons to answer questions such as: Are the Dione and Helene surfaces made of the same material? Did they form in the same region of the Solar System? Is one satellite older than the other? Have they experienced the same amount of space weathering?To provide the most complete evaluation of the Dione and Helene surfaces and advance our understanding of how exogenic processes affect the surfaces of icy satellites we use the synergy of four of the Cassini instruments: UVIS (Ultraviolet Imaging Spectrograph), ISS (Imaging Science Subsystem), VIMS (Visual and Infrared Mapping Spectrometer) and CIRS (Composite Infrared Spectrometer). Composite disk-integrated spectra of both moons have been produced to conduct spectral modeling over a large wavelength range from the ultraviolet to the infrared, from 111nm to 1mm. Until now, most investigations have focused only on one wavelength domain, telling only part of the story. A multi-wavelength analysis allows an in-depth investigation of the surfaces of the Saturnian satellites as each wavelength probes a different layer of the surface. Special attention is directed toward the search for correlations of basic properties (albedo, scattering properties, texture, grain size, composition, porosity, thermal properties) between Dione and Helene.

Space Weathering on Icy Satellites in the Outer Solar System

NASA Technical Reports Server (NTRS)

Clark, R. N.; Perlman, Z.; Pearson, N.; Cruikshank, D. P.

2014-01-01

Space weathering produces well-known optical effects in silicate minerals in the inner Solar System, for example, on the Moon. Space weathering from solar wind and UV (ultraviolet radiation) is expected to be significantly weaker in the outer Solar System simply because intensities are low. However, cosmic rays and micrometeoroid bombardment would be similar to first order. That, combined with the much higher volatility of icy surfaces means there is the potential for space weathering on icy outer Solar System surfaces to show optical effects. The Cassini spacecraft orbiting Saturn is providing evidence for space weathering on icy bodies. The Cassini Visible and Infrared Mapping Spectrometer (VIMS) instrument has spatially mapped satellite surfaces and the rings from 0.35-5 microns and the Ultraviolet Imaging Spectrograph (UVIS) instrument from 0.1 to 0.2 microns. These data have sampled a complex mixing space between H2O ice and non-ice components and they show some common spectral properties. Similarly, spectra of the icy Galilean satellites and satellites in the Uranian system have some commonality in spectral properties with those in the Saturn system. The UV absorber is spectrally similar on many surfaces. VIMS has identified CO2, H2 and trace organics in varying abundances on Saturn's satellites. We postulate that through the spatial relationships of some of these compounds that they are created and destroyed through space weathering effects. For example, the trapped H2 and CO2 observed by VIMS in regions with high concentrations of dark material may in part be space weathering products from the destruction of H2O and organic molecules. The dark material, particularly on Iapetus which has the highest concentration in the Saturn system, is well matched by space-weathered silicates in the .4 to 2.6 micron range, and the spectral shapes closely match those of the most mature lunar soils, another indicator of space weathered material.

Global-scale Observations of the Limb and Disk (GOLD): Hosted Payload Accommodation on a Commercial Satellite

NASA Astrophysics Data System (ADS)

Lankton, M.; Eastes, R.; McClintock, W. E.; Pang, R.; Caffrey, R.; Krywonos, A.

2013-12-01

The Global-Scale Observations of the Limb and Disk (GOLD) mission will perform unprecedented imaging of the Earth's thermosphere and ionosphere (TI) system from geostationary (GEO) orbit. Flying as a hosted payload on a commercial communications satellite, GOLD takes advantage of the resource margins available in the early years of the commercial mission's planned 15-year life. This hosted payload approach is a pathfinder for cost-effective NASA science missions. The affordable ride to GEO makes it possible for an Explorer-class Mission of Opportunity to perform Far UltraViolet (FUV) imaging of nearly a complete hemisphere on a 30-minute cadence. This global-scale, high cadence imaging will enable GOLD to distinguish between spatial and temporal variations in the TI system caused by geomagnetic storms, variations in solar EUV, and forcing from the lower atmosphere. The most significant difference between developing instrumentation for a NASA-owned mission and accomplishing the same task for a commercial satellite is that communications satellites are procured on a faster schedule - 24 to 36 months from satellite contract to launch - than the instrument development. GOLD has partnered with SES Government Solutions (SES-GS), the comsat mission owner-operator, to define instrument interfaces and requirements that will be included in the eventual Request for Proposal to candidate spacecraft vendors. SES-GS launches 3 to 4 missions per year, which allows the GOLD-SES-GS partnership to match the instrument's launch readiness date with a suitable mission. In addition to making geostationary orbit accessible to a science instrument at relatively low cost, commercial communications satellites provides a host platform with very high reliability and long life, easy access to continuous high-speed data downlink and near-real-time data delivery, and stable pointing. SES-GS operates their satellite from established Telemetry, Tracking and Control (TT&C) centers. The GOLD Science Operations Center at the University of Colorado Laboratory for Atmospheric and Space Physics (LASP) will produce instrument command loads for uplink by the TT&C, receive data from the ground station, monitor instrument state of health, and perform quick-look data processing. The GOLD Science Data Center at the University of Central Florida will produce, distribute and archive science data products.

Global modeling of thermospheric airglow in the far ultraviolet

NASA Astrophysics Data System (ADS)

Solomon, Stanley C.

2017-07-01

The Global Airglow (GLOW) model has been updated and extended to calculate thermospheric emissions in the far ultraviolet, including sources from daytime photoelectron-driven processes, nighttime recombination radiation, and auroral excitation. It can be run using inputs from empirical models of the neutral atmosphere and ionosphere or from numerical general circulation models of the coupled ionosphere-thermosphere system. It uses a solar flux module, photoelectron generation routine, and the Nagy-Banks two-stream electron transport algorithm to simultaneously handle energetic electron distributions from photon and auroral electron sources. It contains an ion-neutral chemistry module that calculates excited and ionized species densities and the resulting airglow volume emission rates. This paper describes the inputs, algorithms, and code structure of the model and demonstrates example outputs for daytime and auroral cases. Simulations of far ultraviolet emissions by the atomic oxygen doublet at 135.6 nm and the molecular nitrogen Lyman-Birge-Hopfield bands, as viewed from geostationary orbit, are shown, and model calculations are compared to limb-scan observations by the Global Ultraviolet Imager on the TIMED satellite. The GLOW model code is provided to the community through an open-source academic research license.

A New Method to Cross Calibrate and Validate TOMS, SBUV/2, and SCIAMACHY Measurements

NASA Technical Reports Server (NTRS)

Ahmad, Ziauddin; Hilsenrath, Ernest; Einaudi, Franco (Technical Monitor)

2001-01-01

A unique method to validate back scattered ultraviolet (buv) type satellite data that complements the measurements from existing ground networks is proposed. The method involves comparing the zenith sky radiance measurements from the ground to the nadir radiance measurements taken from space. Since the measurements are compared directly, the proposed method is superior to any other method that involves comparing derived products (for example, ozone), because comparison of derived products involve inversion algorithms which are susceptible to several type of errors. Forward radiative transfer (RT) calculations show that for an aerosol free atmosphere, the ground-based zenith sky radiance measurement and the satellite nadir radiance measurements can be predicted with an accuracy of better than 1 percent. The RT computations also show that for certain values of the solar zenith angles, the radiance comparisons could be better than half a percent. This accuracy is practically independent of ozone amount and aerosols in the atmosphere. Experiences with the Shuttle Solar Backscatter Ultraviolet (SSBUV) program show that the accuracy of the ground-based zenith sky radiance measuring instrument can be maintained at a level of a few tenth of a percent. This implies that the zenith sky radiance measurements can be used to validate Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV/2), and The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) radiance data. Also, this method will help improve the long term precision of the measurements for better trend detection and the accuracy of other BUV products such as tropospheric ozone and aerosols. Finally, in the long term, this method is a good candidate to inter-calibrate and validate long term observations of upcoming operational instruments such as Global Ozone Monitoring Experiment (GOME-2), Ozone Mapping Instrument (OMI), Ozone Dynamics Ultraviolet Spectrometer (ODUS), and Ozone Mapping and Profiler Suite (OMPS).

QUANTITATIVE ULTRAVIOLET SPECTROSCOPY IN WEATHERING OF A MODEL POLYESTER-URETHANE COATING. (R828081E01)

EPA Science Inventory

Spectroscopy was used to quantify the effects of ultraviolet light on a model polyester–urethane coating as it degraded in an accelerated exposure chamber. An explorative calculation of the effective dosage absorbed by the coatings was made and, depending on the quantum...

Nanotechnology in lithium niobate for integrated optic frequency conversion in the UV

NASA Astrophysics Data System (ADS)

Busacca, Alessandro C.; Santini, Claudia; Oliveri, Luigi; Riva-Sanseverino, Stefano; Parisi, Antonino; Cino, Alfonso C.; Assanto, Gaetano

2017-11-01

In the domain of Earth Explorer satellites nanoengineered nonlinear crystals can optimize UV tunable solid-state laser converters. Lightweight sources can be based on Lithium Niobate (LN) domain engineering by electric field poling and guided wave interactions. In this Communication we report the preliminary experimental results and the very first demonstration of UltraViolet second-harmonic generation by first-order quasi-phase-matching in a surface-periodically-poled proton-exchanged LN waveguide. The pump source was a Ti-Sapphire laser with a tunability range of 700- 980 nm and a 40 GHz linewidth. We have measured UV continuous-wave light at 390 nm by means of a lock-in amplifier and of a photodiode with enhanced response in the UV. Measured conversion efficiency was about 1%W-1cm-2. QPM experiments show good agreement with theory and pave the way for a future implementation of the technique in materials less prone to photorefractive damage and wider transparency in the UV, such as Lithium Tantalate.

The Nearest Neutron Stars

NASA Technical Reports Server (NTRS)

Halpern, Jules P.

1996-01-01

Extreme Ultraviolet Explorer (EUVE) satellite observations of the Pulsar PSR J0437-4715, the Seyfert Galaxy RX J0437.4-4711, and the Geminga Pulsar are reported on. The main purpose of the PSR J0437-4715 investigation was to examine its soft X-ray flux. The 20 day EUVE observation of RX J0437.4-4711 constitutes a uniformly sampled soft X-ray light curve of a highly variable Seyfert galaxy whose power spectrum can be examined on timescales from 3 hrs. to several days. A unique aspect of the EUVE observation of RX J0437.4-4711 is its long light curve which we have used to measure the power spectrum of soft X-ray variability at low frequencies. Approximately 2100 counts were detected for the Geminga pulsar in a period of 251,000 s by the EUVE Deep Survey instrument. Geminga presents an unusually difficult problem because its multicomponent X-ray spectrum and pulse profile are indicative of a complex distribution of surface emission, and possibly a contribution from nonthermal emission as well.

Evolution of close binary systems: Observational aspects

NASA Technical Reports Server (NTRS)

Plavec, M. J.

1981-01-01

Detached close binary systems define the main sequence band satisfactorily, but very little is known about the masses of giants and supergiants. High dispersion international ultraviolet explorer satellite observations promise an improvement, since blue companions are now frequently found to late type supergiants. Mu Sagittaril and in particular Xi Aurigae are discussed in more detail. The barium star abundance anomaly appears to be due to mass transfer in interacting systems. The symbiotic stars are another type of binary systems containing late type giants; several possible models for the hotter star and for the type of interaction are discussed. The W Serpentis stars appear to be Algols in the rapid phase of mass transfer, but a possible link relating them to the symbiotics is also indicated. Evidence of hot circumstellar plasmas has now been found in several ordinary Algols; there may exist a smooth transition between very quiescent Algols and the W Serpentis stars. Beta Lyrae is discussed in the light of new spectrophotometric results.

Current and planned use of the Navstar Global Positioning System by NASA

NASA Technical Reports Server (NTRS)

Theiss, Harold L.

1993-01-01

NASA was quick to realize the potential that the Global Positioning System (GPS) had to offer for its many diverse vehicles, experiments and platforms. Soon after the first Block 1 GPS satellites were launched, NASA began to use the tremendous capabilities that they had to offer. Even with a partial GPS constellation in place, important results have been obtained about the shape, orientation and rotation of the earth and calibration of the ionosphere and troposphere. These calibrations enhance geophysical science and facilitate the navigation of interplanetary spacecraft. Some very important results have been obtained in the continuing NASA program for aircraft terminal area operations. Currently, a large amount of activity is being concentrated on real time kinematic carrier phase tracking which has the potential to revolutionize aircraft navigation. This year marks the launch of the first GPS receiver equipped earth-orbiting NASA spacecraft: the Extreme Ultraviolet Explorer and the Ocean Topography Experiment (TOPEX/Poseidon). This paper describes a cross section of GPS-based research at NASA.

Color/magnitude calibration for National Aeronautics and Space Administration (NASA) standard Fixed-Head Star Trackers (FHST)

NASA Technical Reports Server (NTRS)

Landis, J.; Leid, Terry; Garber, A.; Lee, M.

1994-01-01

This paper characterizes and analyzes the spectral response of Ball Aerospace fixed-head star trackers, (FHST's) currently in use on some three-axis stabilized spacecraft. The FHST output is a function of the frequency and intensity of the incident light and the position of the star image in the field of view. The FHST's on board the Extreme Ultraviolet Explorer (EUVE) have had occasional problems identifying stars with a high B-V value. These problems are characterized by inaccurate intensity counts observed by the tracker. The inaccuracies are due to errors in the observed star magnitude values. These errors are unique to each individual FHST. For this reason, data were also collected and analyzed from the Upper Atmosphere Research Satellite (UARS). As a consequence of this work, the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) hopes to improve the attitude accuracy on these missions and to adopt better star selection procedures for catalogs.

Reference models for thermospheric NO

NASA Technical Reports Server (NTRS)

Barth, C. A.

1989-01-01

Nitric oxide has been measured with an ultraviolet spectrometer on the polar-orbiting satellite Solar Mesosphere Explorer (SME) for the period January 1982 to August 1986. The nitric oxide database contains densities at all latitudes sorted into 5 degree bins and at altitudes between 100 and 140 km sorted into 3.3 km-bins. The largest densities occur at latitudes in the auroral zones where the density varies as a function of geomagnetic activity. Variations of a factor of 10 occur between times of intense activity and quiet times. At low latitudes, the nitric oxide density at 110 km varies from a mean value of 3 times 10(exp 7) molecules per cubic cm in January 1982 to a mean value of 4 times 10(exp 6) molecules per cubic cm during solar minimum conditions in 1986. In addition, the low-latitude nitric oxide density varies plus or minus 50 percent with a period of 27 days during times of high solar activity.

The intercomparison of ozone measured from the SME and Nimbus-7 satellites on short and long time scales

NASA Technical Reports Server (NTRS)

Chandra, S.; Mcpeters, R. D.; Srivastava, D. N.

1986-01-01

The spatial and temporal characteristics of ozone density measured from the SBUV (Solar Backscatter Ultraviolet) spectrometer on Nimbus-7 and the UV and the UV and the IR spectrometers on SME (Solar Mesosphere Explorer) are compared in the altitude region near 50 km where the three data sets overlap. Their temporal characteristics, when averaged over the same longitude range, are remarkably similar with respect to seasonal variations and short term fluctuations induced by transient planetary waves. The long term trends in the three data sets, however, differ significantly with each other. Over the three year period after 1982 ozone mixing ratio at 1 mb decreased by about 10 percent based on SEUV measurements but increased by 12 and 30 percent respectively based on SME-IR and SME-UV measurements. None of these estimates are consistent with the predicted decrease of about 2 percent based on solar UV flux and temperature changes during this period.

Maximizing the quantum efficiency of microchannel plate detectors - The collection of photoelectrons from the interchannel web using an electric field

NASA Technical Reports Server (NTRS)

Taylor, R. C.; Hettrick, M. C.; Malina, R. F.

1983-01-01

High quantum efficiency and two-dimensional imaging capabilities make the microchannel plate (MCP) a suitable detector for a sky survey instrument. The Extreme Ultraviolet Explorer satellite, to be launched in 1987, will use MCP detectors. A feature which limits MCP efficiency is related to the walls of individual channels. The walls are of finite thickness and thus form an interchannel web. Under normal circumstances, this web does not contribute to the detector's quantum efficiency. Panitz and Foesch (1976) have found that in the case of a bombardment with ions, electrons were ejected from the electrode material coating the web. By applying a small electric field, the electrons were returned to the MCP surface where they were detected. The present investigation is concerned with the enhancement of quantum efficiencies in the case of extreme UV wavelengths. Attention is given to a model and a computer simulation which quantitatively reproduce the experimental results.

Highlights from 40 Years of Satellite UV Measurements

NASA Technical Reports Server (NTRS)

Bhartia, Pawan K.

2010-01-01

This year we are celebrating the 40th anniversary of the launch of the Backscatter Ultraviolet (BUV) instrument on NASA's Nimbus-4 satellite. The purpose of this instrument was to demonstrate the capability to measure total column ozone and its vertical distribution from space. The success of this instrument led to about a dozen instruments of this type on various NASA and NOAA satellites. These instruments used a single photomultiplier tube (PMT) that restricted the measurements to 6-12 discrete wavelengths in the 250-380 nm range. With the availability of solid-state detector arrays in the past decade it has been possible to make similar measurements but with hyperspectral (contiguous in wavelength) sampling and enhanced spectral resolution. This has allowed global mapping of several weakly-absorbing trace gases including S0 2, NO2, BrO, HCHO, and CIIOCHO. Since these measurements are affected by clouds and aerosols, a great deal of effort has gone into understanding their effect on ultraviolet radiation- both upwelling and downwelling. The downwelling UV radiation is chemically and biologically active and has both negative (genetic damage, air pollution) and positive (production of vitamin D and OH radical) environmental effects. I will discuss how the interaction of Rayleigh-scattered UV radiation with clouds and aerosols produce a variety of interesting effects that are leading to new methods of remote sensing of their properties. The UV measurements can greatly enhance the information that one derives from more traditional methods that use infrared and visible part of the solar spectrum.

Space Shuttle Projects

NASA Image and Video Library

1997-05-08

The mission patch for STS-85 is designed to reflect the broad range of science and engineering payloads on the flight. The primary objectives of the mission were to measure chemical constituents in Earth’s atmosphere with a free-flying satellite and to flight-test a new Japanese robotic arm designed for use on the International Space Station (ISS). STS-85 was the second flight of the satellite known as Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 CRISTA-SPAS-02. CRISTA, depicted on the right side of the patch pointing its trio of infrared telescopes at Earth’s atmosphere, stands for Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere. The high inclination orbit is shown as a yellow band over Earth’s northern latitudes. In the Space Shuttle Discovery’s open payload bay an enlarged version of the Japanese National Space Development Agency’s (NASDA) Manipulator Flight Demonstration (MFD) robotic arm is shown. Also shown in the payload bay are two sets of multi-science experiments: the International Extreme Ultraviolet Hitchhiker (IEH-02) nearest the tail and the Technology Applications and Science (TAS-01) payload. Jupiter and three stars are shown to represent sources of ultraviolet energy in the universe. Comet Hale-Bopp, which was visible from Earth during the mission, is depicted at upper right. The left side of the patch symbolizes daytime operations over the Northern Hemisphere of Earth and the solar science objectives of several of the payloads.

SSUSI-Lite: a far-ultraviolet hyper-spectral imager for space weather remote sensing

NASA Astrophysics Data System (ADS)

Ogorzalek, Bernard; Osterman, Steven; Carlsson, Uno; Grey, Matthew; Hicks, John; Hourani, Ramsey; Kerem, Samuel; Marcotte, Kathryn; Parker, Charles; Paxton, Larry J.

2015-09-01

SSUSI-Lite is a far-ultraviolet (115-180nm) hyperspectral imager for monitoring space weather. The SSUSI and GUVI sensors, its predecessors, have demonstrated their value as space weather monitors. SSUSI-Lite is a refresh of the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) design that has flown on the Defense Meteorological Satellite Program (DMSP) spacecraft F16 through F19. The refresh updates the 25-year-old design and insures that the next generation of SSUSI/GUVI sensors can be accommodated on any number of potential platforms. SSUSI-Lite maintains the same optical layout as SSUSI, includes updates to key functional elements, and reduces the sensor volume, mass, and power requirements. SSUSI-Lite contains an improved scanner design that results in precise mirror pointing and allows for variable scan profiles. The detector electronics have been redesigned to employ all digital pulse processing. The largest decrease in volume, mass, and power has been obtained by consolidating all control and power electronics into one data processing unit.

Spectral slopes of the absorption coefficient of colored dissolved and detrital material inverted from UV-visible remote sensing reflectance

PubMed Central

Wei, Jianwei; Lee, Zhongping; Ondrusek, Michael; Mannino, Antonio; Tzortziou, Maria; Armstrong, Roy

2017-01-01

The spectral slope of the absorption coefficient of colored dissolved and detrital material (CDM), Scdm (units: nm−1), is an important optical parameter for characterizing the absorption spectral shape of CDM. Although highly variable in natural waters, in most remote sensing algorithms, this slope is either kept as a constant or empirically modeled with multiband ocean color in the visible domain. In this study, we explore the potential of semianalytically retrieving Scdm with added ocean color information in the ultraviolet (UV) range between 360 and 400 nm. Unique features of hyperspectral remote sensing reflectance in the UV-visible wavelengths (360–500 nm) have been observed in various waters across a range of coastal and open ocean environments. Our data and analyses indicate that ocean color in the UV domain is particularly sensitive to the variation of the CDM spectral slope. Here, we used a synthesized data set to show that adding UV wavelengths to the ocean color measurements will improve the retrieval of Scdm from remote sensing reflectance considerably, while the spectral band settings of past and current satellite ocean color sensors cannot fully account for the spectral variation of remote sensing reflectance. Results of this effort support the concept to include UV wavelengths in the next generation of satellite ocean color sensors. PMID:29201583

Spectral slopes of the absorption coefficient of colored dissolved and detrital material inverted from UV-visible remote sensing reflectance.

PubMed

Wei, Jianwei; Lee, Zhongping; Ondrusek, Michael; Mannino, Antonio; Tzortziou, Maria; Armstrong, Roy

2016-03-01

The spectral slope of the absorption coefficient of colored dissolved and detrital material (CDM), S cdm (units: nm -1 ), is an important optical parameter for characterizing the absorption spectral shape of CDM. Although highly variable in natural waters, in most remote sensing algorithms, this slope is either kept as a constant or empirically modeled with multiband ocean color in the visible domain. In this study, we explore the potential of semianalytically retrieving S cdm with added ocean color information in the ultraviolet (UV) range between 360 and 400 nm. Unique features of hyperspectral remote sensing reflectance in the UV-visible wavelengths (360-500 nm) have been observed in various waters across a range of coastal and open ocean environments. Our data and analyses indicate that ocean color in the UV domain is particularly sensitive to the variation of the CDM spectral slope. Here, we used a synthesized data set to show that adding UV wavelengths to the ocean color measurements will improve the retrieval of S cdm from remote sensing reflectance considerably, while the spectral band settings of past and current satellite ocean color sensors cannot fully account for the spectral variation of remote sensing reflectance. Results of this effort support the concept to include UV wavelengths in the next generation of satellite ocean color sensors.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Dr. John Meisenheimer, launch weather officer for Explorer 1, speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Far Ultraviolet Spectroscopic Explorer Observations of the Seyfert 1.5 Galaxy NGC 5548 in a Low State

NASA Technical Reports Server (NTRS)

Brotherton, M. S.; Green, R. F.; Kriss, G. A.; Oegerle, W.; Kaiser, M. E.; Zheng, W.; Hutchings, J. B.; Fisher, Richard R. (Technical Monitor)

2001-01-01

We present far-ultraviolet spectra of the Seyfert 1.5 galaxy NGC 5548 obtained in 2000 June with the Far Ultraviolet Spectroscopic Explorer (FUSE). Our data span the observed wavelength range 915-1185 A at a resolution of approximately 20 km s(exp -1). The spectrum shows a weak continuum and emission from O VI (lambda)(lambda)1032, 1038, C III (lambda)977, and He II (lambda)1085. The FUSE data were obtained when the AGN (Active Galactic Nuclei) was in a low state, which has revealed strong, narrow O VI emission lines. We also resolve intrinsic, associated absorption lines of O VI and the Lyman series. Several distinct kinematic components are present, spanning a velocity range of approximately 0 to -1300 km s(exp -1) relative to systemic, with kinematic structure similar to that seen in previous observations of longer wavelength ultraviolet (UV) lines. We explore the relationships between the far-UV (ultraviolet) absorbers and those seen previously in the UV and X-rays. We find that the high-velocity UV absorption component is consistent with being low-ionization, contrary to some previous claims, and is consistent with its non-detection in high-resolution X-ray spectra. The intermediate velocity absorbers, at -300 to -400 km s(exp -1), show H I and O VI column densities consistent with having contributions from both a high-ionization X-ray absorber and a low-ionization UV absorber. No single far-UV absorbing component can be solely identified with the X-ray absorber.

Molecular films associated with LDEF

NASA Technical Reports Server (NTRS)

Crutcher, E. R.; Warner, K. J.

1992-01-01

The molecular films deposited on the surface of the Long Duration Exposure Facility (LDEF) originated from the paints and room-temperature-vulcanized (RTV) silicone materials intentionally used on the satellite and not from residual contaminants. The high silicone content of most of the films and the uniformity of the films indicates a homogenization process in the molecular deposition and suggests a chemically most favored composition for the final film. The deposition on interior surfaces and vents indicated multiple bounce trajectories or repeated deposition-reemission cycles. Exterior surface deposits indicated a significant return flux. Ultraviolet light exposure was required to fix the deposited film as is indicated by the distribution of the films on interior surfaces and the thickness of films at the vent locations. Thermal conditions at the time of exposure to ultraviolet light seems to be an important factor in the thickness of the deposit. Sunrise facing (ram direction) surfaces always had the thicker film. These were the coldest surfaces at the time of their exposure to ultraviolet light. The films have a layered structure suggesting cyclic deposition. As many as 34 distinct layers were seen in the films. The cyclic nature of the deposition and the chemical uniformity of the film one layer to the next suggest an early deposition of the films though there is evidence for the deposition of molecular films throughout the nearly six year exposure of the satellite. A final 'spray' of an organic material associated with water soluble salts occurred very late in the mission. This may have been the result of one of the shuttle dump activities.

Ionospheric-thermospheric UV tomography: 3. A multisensor technique for creating full-orbit reconstructions of atmospheric UV emission

NASA Astrophysics Data System (ADS)

Hei, Matthew A.; Budzien, Scott A.; Dymond, Kenneth F.; Nicholas, Andrew C.; Paxton, Larry J.; Schaefer, Robert K.; Groves, Keith M.

2017-07-01

We present the Volume Emission Rate Tomography (VERT) technique for inverting satellite-based, multisensor limb and nadir measurements of atmospheric ultraviolet emission to create whole-orbit reconstructions of atmospheric volume emission rate. The VERT approach is more general than previous ionospheric tomography methods because it can reconstruct the volume emission rate field irrespective of the particular excitation mechanisms (e.g., radiative recombination, photoelectron impact excitation, and energetic particle precipitation in auroras); physical models are then applied to interpret the airglow. The technique was developed and tested using data from the Special Sensor Ultraviolet Limb Imager and Special Sensor Ultraviolet Spectrographic Imager instruments aboard the Defense Meteorological Satellite Program F-18 spacecraft and planned for use with upcoming remote sensing missions. The technique incorporates several features to optimize the tomographic solutions, such as the use of a nonnegative algorithm (Richardson-Lucy, RL) that explicitly accounts for the Poisson statistics inherent in optical measurements, capability to include extinction effects due to resonant scattering and absorption of the photons from the lines of sight, a pseudodiffusion-based regularization scheme implemented between iterations of the RL code to produce smoother solutions, and the capability to estimate error bars on the solutions. Tests using simulated atmospheric emissions verify that the technique performs well in a variety of situations, including daytime, nighttime, and even in the challenging terminator regions. Lastly, we consider ionospheric nightglow and validate reconstructions of the nighttime electron density against Advanced Research Project Agency (ARPA) Long-range Tracking and Identification Radar (ALTAIR) incoherent scatter radar data.

High accuracy satellite drag model (HASDM)

NASA Astrophysics Data System (ADS)

Storz, M.; Bowman, B.; Branson, J.

The dominant error source in the force models used to predict low perigee satellite trajectories is atmospheric drag. Errors in operational thermospheric density models cause significant errors in predicted satellite positions, since these models do not account for dynamic changes in atmospheric drag for orbit predictions. The Air Force Space Battlelab's High Accuracy Satellite Drag Model (HASDM) estimates and predicts (out three days) a dynamically varying high-resolution density field. HASDM includes the Dynamic Calibration Atmosphere (DCA) algorithm that solves for the phases and amplitudes of the diurnal, semidiurnal and terdiurnal variations of thermospheric density near real-time from the observed drag effects on a set of Low Earth Orbit (LEO) calibration satellites. The density correction is expressed as a function of latitude, local solar time and altitude. In HASDM, a time series prediction filter relates the extreme ultraviolet (EUV) energy index E10.7 and the geomagnetic storm index a p to the DCA density correction parameters. The E10.7 index is generated by the SOLAR2000 model, the first full spectrum model of solar irradiance. The estimated and predicted density fields will be used operationally to significantly improve the accuracy of predicted trajectories for all low perigee satellites.

High accuracy satellite drag model (HASDM)

NASA Astrophysics Data System (ADS)

Storz, Mark F.; Bowman, Bruce R.; Branson, Major James I.; Casali, Stephen J.; Tobiska, W. Kent

The dominant error source in force models used to predict low-perigee satellite trajectories is atmospheric drag. Errors in operational thermospheric density models cause significant errors in predicted satellite positions, since these models do not account for dynamic changes in atmospheric drag for orbit predictions. The Air Force Space Battlelab's High Accuracy Satellite Drag Model (HASDM) estimates and predicts (out three days) a dynamically varying global density field. HASDM includes the Dynamic Calibration Atmosphere (DCA) algorithm that solves for the phases and amplitudes of the diurnal and semidiurnal variations of thermospheric density near real-time from the observed drag effects on a set of Low Earth Orbit (LEO) calibration satellites. The density correction is expressed as a function of latitude, local solar time and altitude. In HASDM, a time series prediction filter relates the extreme ultraviolet (EUV) energy index E10.7 and the geomagnetic storm index ap, to the DCA density correction parameters. The E10.7 index is generated by the SOLAR2000 model, the first full spectrum model of solar irradiance. The estimated and predicted density fields will be used operationally to significantly improve the accuracy of predicted trajectories for all low-perigee satellites.

A technique for directly comparing radiances from two satellites

NASA Technical Reports Server (NTRS)

Mcpeters, Richard D.

1990-01-01

Solar Backscattering Ultraviolet-2 (SBUV/2) instrument on NOAA-9 orbit on June 1987, solar zenith angles of the observations; plot of weekly average differences between SBUV (Nimbus-7 and SBUV/2 (NOAA-9); radiance comparisons for March 1986; time dependence of relative change between SBUV and SBUV/2; and explicit wavelength dependence are presented in viewgraph format. Each is briefly discussed.

Fish-eye view of Hurricane Kenneth in the Pacific Ocean

NASA Image and Video Library

1993-09-13

One of the STS-51 astronauts used a "fish-eye" lens on a 35mm cmaera to photograph this view of Hurricane Kenneth in the Pacific Ocean. The Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer/Shuttle Pallet Satellite (ORFEUS/SPAS) is still in the cargo bay. The Remote Manipulator System (RMS) is extended towards the open payload bay.

Fish-eye view of Hurricane Kenneth in the Pacific Ocean

NASA Technical Reports Server (NTRS)

1993-01-01

One of the STS-51 astronauts used a 'fish-eye' lens on a 35mm cmaera to photograph this view of Hurricane Kenneth in the Pacific Ocean. The Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer/Shuttle Pallet Satellite (ORFEUS/SPAS) is still in the cargo bay. The Remote Manipulator System (RMS) is extended towards the open payload bay.

EUV observation from the Earth-orbiting satellite, EXCEED

NASA Astrophysics Data System (ADS)

Yoshioka, K.; Murakami, G.; Yoshikawa, I.; Ueno, M.; Uemizu, K.; Yamazaki, A.

2010-01-01

An Earth-orbiting small satellite “EXtreme ultraviolet spectrosCope for ExosphEric Dynamics” (EXCEED) which will be launched in 2012 is under development. The mission will carry out spectroscopic and imaging observation of EUV (Extreme Ultraviolet: 60-145 nm) emissions from tenuous plasmas around the planets (Venus, Mars, Mercury, and Jupiter). It is essential for EUV observation to put on an observing site outside the Earth’s atmosphere to avoid the absorption. It is also essential that the detection efficiency must be very high in order to catch the faint signals from those targets. In this mission, we employ cesium iodide coated microchannel plate as a 2 dimensional photon counting devise which shows 1.5-50 times higher quantum detection efficiency comparing with the bared one. We coat the surface of the grating and entrance mirror with silicon carbides by the chemical vapor deposition method in order to archive the high diffraction efficiency and reflectivity. The whole spectrometer is shielded by the 2 mm thick stainless steel to prevent the contamination caused by the high energy electrons from the inner radiation belt. In this paper, we will introduce the mission overview, its instrument, and their performance.

Satellite estimation of incident photosynthetically active radiation using ultraviolet reflectance

NASA Technical Reports Server (NTRS)

Eck, Thomas F.; Dye, Dennis G.

1991-01-01

A new satellite remote sensing method for estimating the amount of photosynthetically active radiation (PAR, 400-700 nm) incident at the earth's surface is described and tested. Potential incident PAR for clear sky conditions is computed from an existing spectral model. A major advantage of the UV approach over existing visible band approaches to estimating insolation is the improved ability to discriminate clouds from high-albedo background surfaces. UV spectral reflectance data from the Total Ozone Mapping Spectrometer (TOMS) were used to test the approach for three climatically distinct, midlatitude locations. Estimates of monthly total incident PAR from the satellite technique differed from values computed from ground-based pyranometer measurements by less than 6 percent. This UV remote sensing method can be applied to estimate PAR insolation over ocean and land surfaces which are free of ice and snow.

Feasibility of using Extreme Ultraviolet Explorer (EUVE) reaction wheels to satisfy Space Infrared Telescope Facility (SIRTF) maneuver requirements

NASA Technical Reports Server (NTRS)

Lightsey, W. D.

1990-01-01

A digital computer simulation is used to determine if the extreme ultraviolet explorer (EUVE) reaction wheels can provide sufficient torque and momentum storage capability to meet the space infrared telescope facility (SIRTF) maneuver requirements. A brief description of the pointing control system (PCS) and the sensor and actuator dynamic models used in the simulation is presented. A model to represent a disturbance such as fluid sloshing is developed. Results developed with the simulation, and a discussion of these results are presented.

Surface evaluation of the grazing incidence mirrors for the Extreme Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Green, James; Finley, David S.; Bowyer, Stuart; Malina, Roger F.

1987-01-01

The EUV scattering from the Wolter-Schwarzschild type I short wavelength scanner mirror aboard the Extreme Ultraviolet Explorer is measured, and the results are used to evaluate the surface microroughness of the mirror. It is found that the most likely values for the mirror surface are sigma = 20 A, and rho = 40 microns. These results are consistent with previous estimates, but with a higher degree of certainty. The full-scale simulation presented here allows over 99 percent of the light distribution to be reasonably modeled.

Canadian Thesis Abstracts: Synthèse spectrale de jeunes populations stellaires dans; l'ultraviolet lointain

NASA Astrophysics Data System (ADS)

Pellerin, Anne

2005-02-01

Le but de cette thèse était de développer et tester la technique de synthè;se spectrale évolutive aux longueurs d'onde de l'ultraviolet lointain. Jusquà récemment, cette technique n'était appliqué quà des données au-delà de 1200 Å. Le lancement du satellite FUSE en 1999 a permis d'explorer le domaine de l'ultraviolet lointain (900-1200 Å) avec une grande résolution spectrale. J'ai donc utilisé les spectres du satellite FUSE de 228 étoiles chaudes de type O et B, de 24 galaxies à sursauts de formation d'étoiles et de quatre galaxies Seyfert. Dans un premier temps, j'ai caractérisé le comportement des profils de raies stellaires en fonction du type spectral, de la classe de luminosité et de la métallicité des étoiles. Les raies O vi >>1031.9, 1037.6, S iv >>1062.7, 1073.0, 1073.5, P v>>1118.0, 1128.0 et C iii >1175.6 ont été identifiées comme étant des indicateurs stellaires potentiellement intéressants pour la synthèse spectrale. Le domaine de longueur d'onde inférieur à 1000 Å couvert par FUSEmontre aussi des signatures stellaires mais qui sont peu intéressantes pour la synthèse en raison de la contamination interstellaire. J'ai ensuite crééé; une bibliothèque de spectres FUSE qui a été intégrée au code de synthèse LavalSBafin de produire des spectres de synthèse dans l'ultraviolet lointain pour diverses populations stellaires théoriques. Il s'est avéré que les raies de P vet de C iii sont d'excellents indicateurs d'âge, de métallicité et de fonction de masse initiale de la population stellaire, tandis que les raies de O vi et de S ivne sont pas aussi efficaces. La comparaison des spectres FUSEde galaxies avec les spectres synthétiques a révèlé des âges entre 2.5 et 18 millions d'années pour un large éventail de métallicités. On trouve aussi une forte dominance du mode instantané de formation stellaire. Ce travail a aussi permis d'estimer quantitativement l'extinction interne et les masses stellaires impliquées dans les sursauts. La synthèse des raies de l'ultraviolet lointain s'est avérée beaucoup plus précise que la synthèse à > 1200 Å en raison de la résolution spectrale exceptionnelle de FUSE et parce que les raies stellaires n'ont pas de profils saturés, même aux métallicités élevées. Les propriétés physiques globales des 24 galaxies à sursauts ont aussi été étudiées dans leur ensemble afin de mieux décrire le phénomène des sursauts de formation stellaires.

Temporal correlations between impulsive ultraviolet and hard X-ray bursts in solar flares observed with high time resolution

NASA Technical Reports Server (NTRS)

Cheng, Chung-Chieh; Vanderveen, K.; Orwig, L. E.; Tandberg-Hanssen, E.

1988-01-01

The impulsive phase of solar flares has been simultaneously observed in the ultraviolet O V line, the UV continuum, and hard X-rays with a time resolution of 0.128 s by the SMM satellite. A close time correspondence between the three impulsive components is found, with the best correlation being at the peak of the impulsive phase. Individual bursts or fast features in the O V and the UV continuum are shown to lag behind the corresponding hard X-ray features. None of the considered energy transport mechanisms (thermal conduction, a nonthermal electron beam, electron hole boring, UV radiation, and Alfven waves) are able to consistently account for the observed temporal correlations.

Maximizing the Science Output of GOES-R SUVI during Operations

NASA Astrophysics Data System (ADS)

Shaw, M.; Vasudevan, G.; Mathur, D. P.; Mansir, D.; Shing, L.; Edwards, C. G.; Seaton, D. B.; Darnel, J.; Nwachuku, C.

2017-12-01

Regular manual calibrations are an often-unavoidable demand on ground operations personnel during long-term missions. This paper describes a set of features built into the instrument control software and the techniques employed by the Solar Ultraviolet Imager (SUVI) team to automate a large fraction of regular on-board calibration activities, allowing SUVI to be operated with little manual commanding from the ground and little interruption to nominal sequencing. SUVI is a Generalized Cassegrain telescope with a large field of view that images the Sun in six extreme ultraviolet (EUV) narrow bandpasses centered at 9.4, 13.1, 17.1, 19.5, 28.4 and 30.4 nm. It is part of the payload of the Geostationary Operational Environmental Satellite (GOES-R) mission.

The Extreme Ultraviolet Explorer mission

NASA Technical Reports Server (NTRS)

Malina, R. F.; Battel, S. J.

1989-01-01

The Extreme Ultraviolet Explorer (EUVE) mission will be the first user of NASA's new Explorer platform. The instrumentation included on this mission consists of three grazing incidence scanning telescopes, a deep survey instrument and an EUV spectrometer. The bandpass covered is 80 to 900 A. During the first six months of the mission, the scanning telescopes will be used to make all-sky maps in four bandpasses; astronomical sources wil be detected and their positions determined to an accuracy of 0.1 deg. The deep survey instrument will survey the sky with higher sensitivity along the ecliptic in two bandpasses between 80 and 500 A. Engineering and design aspects of the science payload and features of the instrument design are described.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

A replica of the Explorer 1 satellite is seen on display during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Assimilation of Satellite Ozone Observations

NASA Technical Reports Server (NTRS)

Stajner, I.; Winslow, N.; Wargan, K.; Hayashi, H.; Pawson, S.; Rood, R.

2003-01-01

This talk will discuss assimilation of ozone data from satellite-borne instruments. Satellite observations of ozone total columns and profiles have been measured by a series of Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV) instruments, and more recently by the Global Ozone Monitoring Experiment. Additional profile data are provided by instruments on NASA's Upper Atmosphere Research Satellite and by occultation instruments on other platforms. Instruments on Envisat' and future EOS Aura satellite will supply even more comprehensive data about the ozone distribution. Satellite data contain a wealth of information, but they do not provide synoptic global maps of ozone fields. These maps can be obtained through assimilation of satellite data into global chemistry and transport models. In the ozone system at NASA's Data Assimilation Office (DAO) any combination of TOMS, SBUV, and Microwave Limb sounder (MLS) data can be assimilated. We found that the addition of MLS to SBUV and TOMS data in the system helps to constrain the ozone distribution, especially in the polar night region and in the tropics. The assimilated ozone distribution in the troposphere and lower stratosphere is sensitive also to finer changes in the SBUV and TOMS data selection and to changes in error covariance models. All results are established by comparisons of assimilated ozone with independent profiles from ozone sondes and occultation instruments.

Extreme Ultraviolet Explorer. Long look at the next window

NASA Technical Reports Server (NTRS)

Maran, Stephen P.

1991-01-01

The Extreme Ultraviolet Explorer (EUVE) will map the entire sky to determine the existence, direction, brightness, and temperature of thousands of objects that are sources of so-called extreme ultraviolet (EUV) radiation. The EUV spectral region is located between the x-ray and ultraviolet regions of the electromagnetic spectrum. From the sky survey by EUVE, astronomers will determine the nature of sources of EUV light in our galaxy, and infer the distribution of interstellar gas for hundreds of light years around the solar system. It is from this gas and the accompanying dust in space that new stars and solar systems are born and to which evolving and dying stars return much of their material in an endless cosmic cycle of birth, death, and rebirth. Besides surveying the sky, astronomers will make detailed studies of selected objects with EUVE to determine their physical properties and chemical compositions. Also, they will learn about the conditions that prevail and the processes at work in stars, planets, and other sources of EUV radiation, maybe even quasars. The EUVE mission and instruments are described. The objects that EUVE will likely find are described.

Probing the infrared counterparts of diffuse far-ultraviolet sources in the Galaxy

NASA Astrophysics Data System (ADS)

Saikia, Gautam; Shalima, P.; Gogoi, Rupjyoti; Pathak, Amit

2017-12-01

Recent availability of high quality infrared (IR) data for diffuse regions in the Galaxy and external galaxies have added to our understanding of interstellar dust. A comparison of ultraviolet (UV) and IR observations may be used to estimate absorption, scattering and thermal emission from interstellar dust. In this paper, we report IR and UV observations for selective diffuse sources in the Galaxy. Using archival mid-infrared (MIR) and far-infrared (FIR) observations from Spitzer Space Telescope, we look for counterparts of diffuse far-ultraviolet (FUV) sources observed by the Voyager, Far Ultraviolet Spectroscopic Explorer (FUSE) and Galaxy Evolution Explorer (GALEX) telescopes in the Galaxy. IR emission features at 8 μm are generally attributed to Polycyclic Aromatic Hydrocarbon (PAH) molecules, while emission at 24 μm are attributed to Very Small Grains (VSGs). The data presented here is unique and our study tries to establish a relation between various dust populations. By studying the FUV-IR correlations separately at low and high latitude locations, we have identified the grain component responsible for the diffuse FUV emission.

The Antarctic Ice Sheet, Sea Ice, and the Ozone Hole: Satellite Observations of how they are Changing

NASA Technical Reports Server (NTRS)

Parkinson, Claire L.

2012-01-01

Antarctica is the Earth's coldest and highest continent and has major impacts on the climate and life of the south polar vicinity. It is covered almost entirely by the Earth's largest ice sheet by far, with a volume of ice so great that if all the Antarctic ice were to go into the ocean (as ice or liquid water), this would produce a global sea level rise of about 60 meters (197 feet). The continent is surrounded by sea ice that in the wintertime is even more expansive than the continent itself and in the summertime reduces to only about a sixth of its wintertime extent. Like the continent, the expansive sea ice cover has major impacts, reflecting the sun's radiation back to space, blocking exchanges between the ocean and the atmosphere, and providing a platform for some animal species while impeding other species. Far above the continent, the Antarctic ozone hole is a major atmospheric phenomenon recognized as human-caused and potentially quite serious to many different life forms. Satellites are providing us with remarkable information about the ice sheet, the sea ice, and the ozone hole. Satellite visible and radar imagery are providing views of the large scale structure of the ice sheet never seen before; satellite laser altimetry has produced detailed maps of the topography of the ice sheet; and an innovative gravity-measuring two-part satellite has allowed mapping of regions of mass loss and mass gain on the ice sheet. The surrounding sea ice cover has a satellite record that goes back to the 1970s, allowing trend studies that show a decreasing sea ice presence in the region of the Bellingshausen and Amundsen seas, to the west of the prominent Antarctic Peninsula, but increasing sea ice presence around much of the rest of the continent. Overall, sea ice extent around Antarctica has increased at an average rate of about 17,000 square kilometers per year since the late 1970s, as determined from satellite microwave data that can be collected under both light and dark conditions and irrespective of whether clouds are in the way between the surface and the satellite. In contrast, the highest quality satellite measurements of the ozone hole use ultraviolet light, which requires daylight conditions. Still, satellite ultraviolet measurements of the ozone hole have also been made since the late 1970s, and these show a marked increase in the area and depth of the ozone hole in the 1980s and early 1990s, followed by a welcome leveling off of both measures since the mid-1990s.

Overview of battery usage in NASA/GSFC LEO and GEO missions

NASA Technical Reports Server (NTRS)

Yi, Thomas

1989-01-01

In July, 1989, Cosmic Background Explorer (COBE) will be launched from a Delta rocket to study the big bang theory. The COBE, which is in a LEO/Polar orbit, will have two 20 Ah NiCd batteries, and 18 cells per battery, made by McDonnell Douglas Company. In December, 1989, National Oceanic and Atmospheric Administration (NOAA-D) will be launched from an Atlas rocket for weather observation purposes. NOAA-D, which is in a LEO/Polar morning orbit, will have two 26.5 Ah NiCd batteries, and 17 cells per battery, made by Ge-Astro East Windor. NOAA-I, which is scheduled for May, 1991 launch in a LEO/Polar afternoon orbit, will have three 26.5 Ah NiCd batteries, 17 cells per battery, made by GE-Astro East Windor. In April, 1990, Gamma Ray Observatory (GRO) will be launched from STS37 to study the gamma ray radiation phenomenon. GRO, which is in a LEO orbit, will have two modular power systems (MPS) made by McDonnell Douglas, each MPS consisting of three 50 Ah NiCd batteries, 22 cells per battery. In July, 1990, Geostationary Operational Environmental Satellite (GOES-I) will be launched from an Atlas I rocket for weather observation purposes. GOES-I, which is in a GEO orbit, will have two 12 Ah NiCd batteries, 28 cells per battery, made by Ford Aerospace and Communications Company. In December, 1990, Tracking and Data Relay Satellite (TDRS-E) will be launched from STS43 for communication purposes. TDRS-E, which is in a GEO orbit, will have three 40 Ah NiCd batteries, 24 cells per battery, made by TRW. In August, 1991, Extreme Ultraviolet Explorer (EUVE) will be launched from a Delta rocket. EUVE, which is in a LEO orbit, will have one modular power system (MPS) made by McDonnell Douglas. In December, 1991, Upper Atmosphere Research Satellite (UARS) will be launched from STS50 to study the Earth's ozone layer and other environmental concerns. UARS, which is in a 56 deg inclination LEO orbit, will have one modular power systems (MPS) made by McDonnell Douglas.

Spacecraft technology. [development of satellites and remote sensors

NASA Technical Reports Server (NTRS)

1975-01-01

Developments in spacecraft technology are discussed with emphasis on the Explorer satellite program. The subjects considered include the following: (1) nutational behavior of the Explorer-45 satellite, (2) panoramic sensor development, (3) onboard camera signal processor for Explorer satellites, and (4) microcircuit development. Information on the zero gravity testing of heat pipes is included. Procedures for cleaning heat treated aluminum heat pipes are explained. The development of a five-year magnetic tape, an accurate incremental angular encoder, and a blood freezing apparatus for leukemia research are also discussed.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

During a ceremony at Cape Canaveral Air Force Station's Space launch Complex 26 a historical marker has been unveiled noting the launch of America's first satellite, Explorer 1. The satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Astro-1 Image Taken by the Ultraviolet Imaging Telescope

NASA Technical Reports Server (NTRS)

1990-01-01

This is a presentation of two comparison images of the Spiral Galaxy M81 in the constellation URA Major. The galaxy is about 12-million light years from Earth. The left image is the Spiral Galaxy M81 as photographed by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 Mission (STS-35) on December 9, 1990. This UIT photograph, made with ultraviolet light, reveals regions where new stars are forming at a rapid rate. The right image is a photograph of the same galaxy in red light made with a 36-inch (0.9-meter) telescope at the Kitt Peak National Observatory near Tucson, Arizona. The Astro Observatory was designed to explore the universe by observing and measuring ultraviolet radiation from celestial objects. Three instruments made up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had management responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Michael Watkins, Director of NASA's Jet Propulsion Laboratory, left, Susan Finley, who began working at NASA's Jet Propulsion Laboratory in January 1958 as a "human computer", center, and Thomas Zurbuchen, Associate Administrator for NASA's Science Mission Directorate, right, reenact the famous picture of Dr. William H. Pickering, Dr. James A. van Allen, and Dr. Wernher von Braun, hoisting a model of Explorer 1 above their heads at a press conference announcing the satellite's success with a replica of the Explorer 1 satellite during an event celebrating the 60th Anniversary of the Explorer 1 mission and the discovery of Earth's radiation belts, Wednesday, Jan. 31, 2018, at the National Academy of Sciences in Washington. The first U.S. satellite, Explorer 1, was launched from Cape Canaveral on January 31, 1958. The 30-pound satellite would yield a major scientific discovery, the Van Allen radiation belts circling our planet, and begin six decades of groundbreaking space science and human exploration. (NASA/Joel Kowsky)

Multi-Satellite Attitude Prediction program/Orbiting Solar Observatory-8 (MSAP/OSO-8) operating guide

NASA Technical Reports Server (NTRS)

Tate, V. H.; Wyckoff, D. C.; Decicco, J. M.

1976-01-01

The sun's lower corona and chromosphere and their interaction in the X-ray and ultraviolet (UV) spectral regions were investigated to better understand the transport of energy from the photosphere to the corona. The interaction between the solar electromagnetic and particle radiation and the earth's environment was studied and the background component of cosmic X-rays was discussed.

Surface Composition and Physical Mixture State of the Regoliths of Outer Solar System Satellites: The Role of Scattering and Absorption by the non-Ice Components and Implications for Rayleigh Absorption and Rayleigh Scattering

NASA Astrophysics Data System (ADS)

Clark, R. N.; Perlman, Z. S.; Pearson, N.; Hendrix, A. R.; Cuzzi, J. N.; Cruikshank, D. P.; Bradley, E. T.; Filacchione, G.; Nicholson, P. D.; Hedman, M. M.; Brown, R. H.; Buratti, B. J.; Baines, K. H.; Sotin, C.; Nelson, R. M.

2014-12-01

Many outer Solar System satellites have surfaces dominated by water ice and a mysterious material(s) causing strong visible to ultraviolet absorption along with trace other compounds with infrared absorptions, including CO2 and organics. Various mechanisms have been proposed for the UV absorber, including tholins, iron oxides, and nano-sized metallic iron particles (e.g. see Clark et al., 2012, Icarus v218 p831, and references therein). We have constructed extensive laboratory analog measurements and radiative transfer modeling of the materials and scattering conditions that can contribute to the optical properties seen on outer Solar System satellites. We have successfully modeled Rayleigh absorption and Rayleigh scattering to produce spectral shapes typical of those seen in spectra of icy Solar System satellites, including those in the Saturn system observed with the Cassini UVIS and VIMS instruments. While it is easy to create these absorptions with radiative transfer modeling, it has been more difficult to do with laboratory analogs. We are finding that laboratory analogs refine and restricts the possible mixing states of the UV absorber in icy satellite surfaces. We have found that just because a particle is highly absorbing, as in metallic iron, if the particle is not embedded in another matrix, scattering will dominate over absorption and Rayleigh absorption will not be observed. Further, the closer the indices of refraction match between the absorbing particle and the matrix, there will be less scattering and more absorption will occur. But we have also found this to be true with other absorbing material, like Tholins. It is very difficult to obtain the very low reflectances observed in the UV in icy satellite spectra using traditional intimate mixtures, as scattering and first surface reflections contribute significantly to the reflectance. The solution, both from radiative transfer modeling and laboratory analogs point to embedded absorbing materials. For example, nano-phase metallic iron embedded in a less absorbing silicate matrix as meteoritic dust infall onto satellitesurfaces is one explanation. An alternative would be tholins embedded in the ice. Spectral features should be able to distinguish between these and other possibilities and will be explored.

Spectral classification with the International Ultraviolet Explorer: An atlas of B-type spectra

NASA Technical Reports Server (NTRS)

Rountree, Janet; Sonneborn, George

1993-01-01

New criteria for the spectral classification of B stars in the ultraviolet show that photospheric absorption lines in the 1200-1900A wavelength region can be used to classify the spectra of B-type dwarfs, subgiants, and giants on a 2-D system consistent with the optical MK system. This atlas illustrates a large number of such spectra at the scale used for classification. These spectra provide a dense matrix of standard stars, and also show the effects of rapid stellar rotation and stellar winds on the spectra and their classification. The observational material consists of high-dispersion spectra from the International Ultraviolet Explorer archives, resampled to a resolution of 0.25 A, uniformly normalized, and plotted at 10 A/cm. The atlas should be useful for the classification of other IUE high-dispersion spectra, especially for stars that have not been observed in the optical.

Nearby Newborns

NASA Image and Video Library

2004-12-21

This image shows six of the three-dozen "ultraviolet luminous galaxies" spotted in our corner of the universe by NASA's Galaxy Evolution Explorer. These massive galaxies greatly resemble newborn galaxies that were common in the early universe. The discovery came as a surprise, because astronomers had thought that the universe's "birth-rate" had declined, and that massive galaxies were no longer forming. The galaxies, located in the center of each panel, were discovered after the Galaxy Evolution Explorer scanned a large portion of the sky with its highly sensitive ultraviolet-light detectors. Because young stars pack most of their light into ultraviolet wavelengths, young galaxies appear to the Galaxy Evolution Explorer like diamonds in a field of stones. Astronomers mined for these rare "gems" before, but missed them because they weren't able to examine a large enough slice of the sky. The Galaxy Evolution Explorer surveyed thousands of nearby galaxies before finding three-dozen newborns. While still relatively close in astronomical terms, these galaxies are far enough away to appear small to the Galaxy Evolution Explorer. Clockwise beginning from the upper left, they are called: GALEX_J232539.24+004507.1, GALEX_J231812.98-004126.1, GALEX_J015028.39+130858.5, GALEX_J021348.52+125951.3, GALEX_J143417.15+020742.5, GALEX_J020354.02-092452.5. http://photojournal.jpl.nasa.gov/catalog/PIA07143

Spacelab

NASA Image and Video Library

1990-12-09

This is a presentation of two comparison images of the Spiral Galaxy M81 in the constellation URA Major. The galaxy is about 12-million light years from Earth. The left image is the Spiral Galaxy M81 as photographed by the Ultraviolet Imaging Telescope (UIT) during the Astro-1 Mission (STS-35) on December 9, 1990. This UIT photograph, made with ultraviolet light, reveals regions where new stars are forming at a rapid rate. The right image is a photograph of the same galaxy in red light made with a 36-inch (0.9-meter) telescope at the Kitt Peak National Observatory near Tucson, Arizona. The Astro Observatory was designed to explore the universe by observing and measuring ultraviolet radiation from celestial objects. Three instruments made up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had management responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

Remote sensing strategies for global resource exploration and environmental management

NASA Astrophysics Data System (ADS)

Henderson, Frederick B.

Since 1972, satellite remote sensing, when integrated with other exploration techniques, has demonstrated operational exploration and engineering cost savings and reduced exploration risks through improved geological mapping. Land and ocean remote sensing satellite systems under development for the 1990's by the United States, France, Japan, Canada, ESA, Russia, China, and others, will significantly increase our ability to explore for, develop, and manage energy and mineral resources worldwide. A major difference between these systems is the "Open Skies" and "Non-Discriminatory Access to Data" policies as have been practiced by the U.S. and France and the restrictive nationalistic data policies as have been practiced by Russia and India. Global exploration will use satellite remote sensing to better map regional structural and basin-like features that control the distribution of energy and mineral resources. Improved sensors will better map lithologic and stratigraphic units and identify alteration effects in rocks, soils, and vegetation cover indicative of undiscovered subsurface resources. These same sensors will also map and monitor resource development. The use of satellite remote sensing data will grow substantially through increasing integration with other geophysical, geochemical, and geologic data using improved geographic information systems (GIS). International exploration will focus on underdeveloped countries rather than on mature exploration areas such as the United States, Europe, and Japan. Energy and mineral companies and government agencies in these countries and others will utilize available remote sensing data to acquire economic intelligence on global resources. If the "Non-Discriminatory Access to Data" principle is observed by satellite producing countries, exploration will remain competitive "on the ground". In this manner, remote sensing technology will continue to be developed to better explore for and manage the world's needed resources. If, however, satellite producing countries follow the Russian and Indian lead and restrict civil satellite data as tools of their national security and economic policies, remote sensing technology may become internationally competitive in space, redundant, prohibitively expensive, and generally unavailable to the world community.

Epidemiologic evidence for different roles of ultraviolet A and B radiation in melanoma mortality rates.

PubMed

Garland, Cedric F; Garland, Frank C; Gorham, Edward D

2003-07-01

The action spectrum of ultraviolet radiation mainly responsible for melanoma induction is unknown, but evidence suggests it could be ultraviolet A (UVA), which has a different geographic distribution than ultraviolet B (UVB). This study assessed whether melanoma mortality rates are more closely related to the global distribution of UVA or UVB. UVA and UVB radiation and age-adjusted melanoma mortality rates were obtained for all 45 countries reporting cancer data to the World Health Organization. Stratospheric ozone data were obtained from NASA satellites. Average population skin pigmentation was obtained from skin reflectometry measurements. Paradoxically, melanoma mortality rates decreased with increasing UVB in men (r = -0.48, p < 0.001), and women (r = -0.57, p < 0.001), and with increasing UVA in both sexes. By contrast, rates were positively associated with increasing UVA/UVB ratio in men (r = + 0.49, p < 0.001) and women (r = + 0.55, p < 0.001). After multiple adjustment that included controlling for skin pigmentation, only UVA was associated with melanoma mortality rates in men (p < 0.02) with a suggestive but non-significant trend present in women (p = 0.12). UVA radiation was associated with melanoma mortality rates after controlling for UVB and average pigmentation. The results require confirmation in observational studies.

STS-51 Discovery launch

NASA Image and Video Library

1993-09-12

STS051-S-108 (12 Sept. 1993) --- The Space Shuttle Discovery soars toward a nine-day stay in Earth-orbit to support the mission. Launch occurred at 7:45 a.m. (EDT) September 12, 1993. Note the diamond shock effect coming from the thrust of the three main engines. Onboard the shuttle were astronauts Frank L. Culbertson, Jr., William F. Readdy, Daniel W. Bursch, James H. Newman and Carl E. Walz, along with a number of payloads. The payloads included the Advanced Communications Technology Satellite (ACTS) with its Transfer Orbit Stage (TOS), the Orbiting Retrievable Far and Extreme Ultraviolet Spectrometer (ORFEUS) and its Shuttle Pallet Satellite (SPAS) carrier. This photograph was taken with a 35mm camera.

Use of satellite data and modeling to asses the influence of stratospheric processes on the troposphere

NASA Technical Reports Server (NTRS)

Nathan, Terrence R.; Yarger, Douglas N.

1989-01-01

The research is comprised of the following tasks: use of simple analytical and numerical models of a coupled troposphere-stratosphere system to examine the effects of radiation and ozone on planetary wave dynamics and the tropospheric circulation; use of satellite data obtained from the Nimbus 7 Limb Infrared Monitor of the Stratosphere (LIMS) instrument and Solar Backscattered Ultraviolet (SBUV) experiment, in conjunction with National Meteorological Center (NMC) data, to determine the planetary wave vertical structures, dominant wave spectra, ozone spectra, and time variations in diabatic heating rate; and synthesis of the modeling and observational results to provide a better understanding of the effects that stratospheric processes have on tropospheric dynamics.

Nimbus-7 data product summary

NASA Technical Reports Server (NTRS)

Oakes, Arnold G.; Han, Daesoo; Kyle, H. Lee; Feldman, Gene Carl; Fleig, Albert J.; Hurley, Edward J.; Kaufman, Barbara A.

1989-01-01

Data sets resulting from the first nine years of operations of the Nimbus-7 Satellite are briefly described. After a brief description of the Nimbus-7 Mission, each of the eight experiments on-board the satellite (Coastal Zone Color Scanner (CZCS), Earth Radiation Budget (ERB), Limb Infrared Monitor of the Stratosphere (MIMS), Stratospheric Aerosol Measurement II (SAM II), Stratospheric and Mesospheric Sounder (SAMS), Solar Backscatter Ultraviolet/Total Ozone Mapping Spectrometer (SBUV/TOMS), Scanning Multichannel Microwave Radiometer (SMMR) and the Temperature Humidity Infrared Radiometer (THIR) are introduced and their respective data products are described in terms of media, general format, and suggested applications. Extensive references are provided. Instructions for obtaining further information, and for ordering data products are given.

LIMS Instrument Package (LIP) balloon experiment: Nimbus 7 satellite correlative temperature, ozone, water vapor, and nitric acid measurements

NASA Technical Reports Server (NTRS)

Lee, R. B., III; Gandrud, B. W.; Robbins, D. E.; Rossi, L. C.; Swann, N. R. W.

1982-01-01

The Limb Infrared Monitor of the Stratosphere (LIMS) LIP balloon experiment was used to obtain correlative temperature, ozone, water vapor, and nitric acid data at altitudes between 10 and 36 kilometers. The performance of the LIMS sensor flown on the Nimbus 7 Satellite was assessed. The LIP consists of the modified electrochemical concentration cell ozonesonde, the ultraviolet absorption photometric of ozone, the water vapor infrared radiometer sonde, the chemical absorption filter instrument for nitric acid vapor, and the infrared radiometer for nitric acid vapor. The limb instrument package (LIP), its correlative sensors, and the resulting data obtained from an engineering and four correlative flights are described.

Artist concept of Shuttle Solar Backscatter UV (SSBUV) flight configuration

NASA Technical Reports Server (NTRS)

1989-01-01

Artist concept of STS-34 payload bay (PLB) experiment is titled SSBUV FLIGHT CONFIGURATION. The labeled drawing of the Shuttle Solar Backscatter Ultraviolet (UV) (SSBUV) get away special (GAS) canisters identifies the adapter beam, motorized door mechanism, instrument canister, support canister, bottom hat, and interconnect cable. The GAS canisters will be mounted on the starboard wall of Atlantis', Orbiter Vehicle (OV) 104's, PLB. One canister contains an instrument nearly identical to that flown on the satellite. The second canister provides power, data, and command systems. During STS-34, SSBUV instrument will calibrate similar ozone measuring space-based instruments on the National Oceanic and Atmospheric Administration's (NOAA's) TIROS satellites (NOAA-9 and NOAA-11). SSBUV uses the Space Shuttle's orbital flight path to assess instrument performance by directly comparing data from identical instruments aboard TIROS spacecraft, as the Shuttle and the satellite pass over the same E

Solar Radiation and Climate Experiment (SORCE) Satellite

NASA Technical Reports Server (NTRS)

2003-01-01

This is a close-up of the NASA-sponsored Solar Radiation and Climate Experiment (SORCE) Satellite. The SORCE mission, launched aboard a Pegasus rocket January 25, 2003, will provide state of the art measurements of incoming x-ray, ultraviolet, visible, near-infrared, and total solar radiation. Critical to studies of the Sun and its effect on our Earth system and mankind, SORCE will provide measurements that specifically address long-term climate change, natural variability and enhanced climate prediction, and atmospheric ozone and UV-B radiation. Orbiting around the Earth accumulating solar data, SORCE measures the Sun's output with the use of state-of-the-art radiometers, spectrometers, photodiodes, detectors, and bolo meters engineered into instruments mounted on a satellite observatory. SORCE is carrying 4 instruments: The Total Irradiance Monitor (TIM); the Solar Stellar Irradiance Comparison Experiment (SOLSTICE); the Spectral Irradiance Monitor (SIM); and the XUV Photometer System (XPS).

VizieR Online Data Catalog: ANS UV Catalogue of Point Sources (Wesselius+ 1982)

NASA Astrophysics Data System (ADS)

Wesselius, P. R.; van Duinen, R. J.; de Jonge, A. R. W.; Aalders, J. W. G.; Luinge, W.; Wildeman, K. J.

2001-08-01

This catalog is a result of the observations made with the Astronomical Netherlands Satellite (ANS) which operated between October 1974 and April 1976. The ANS satellite observed in five UV channels centered around 150, 180, 220, 250 and 330nm. The photometric bands are: ------------------------------------------------------------------------- - Band designation 15N 15W 18 22 25 33 ------------------------------------------------------------------------- - Central wavelength (nm) 154.5 154.9 179.9 220.0 249.3 329.4 Bandwidth (nm) 5.0 14.9 14.9 20.0 15.0 10.1 ------------------------------------------------------------------------- - The reported magnitudes were obtained from mean count rates converted to fluxes using the ANS absolute calibration of Wesselius et al. (1980A&A....85..221W). In addition to the ultraviolet magnitudes, the catalog contains positions taken from the satellite pointing, spectral types, and UBV data from other sources as well as comments on duplicity, variability, and miscellaneous notes concerning individual objects. (1 data file).

Space Shuttle Projects

NASA Image and Video Library

1995-05-27

The crew patch of STS-72 depicts the Space Shuttle Endeavour and some of the payloads on the flight. The Japanese satellite, Space Flyer Unit (SFU) is shown in a free-flying configuration with the solar array panels deployed. The inner gold border of the patch represents the SFU's distinct octagonal shape. Endeavour’s rendezvous with and retrieval of SFU at an altitude of approximately 250 nautical miles. The Office of Aeronautics and Space Technology's (OAST) flyer satellite is shown just after release from the Remote Manipulator System (RMS). The OAST satellite was deployed at an altitude of 165 nautical miles. The payload bay contains equipment for the secondary payloads - the Shuttle Laser Altimeter (SLA) and the Shuttle Solar Backscatter Ultraviolet Instrument (SSBUV). There were two space walks planned to test hardware for assembly of the International Space Station. The stars represent the hometowns of the crew members in the United States and Japan.

LYMAN - The far ultraviolet explorer

NASA Technical Reports Server (NTRS)

Moos, Warren; Osantowski, John F.

1989-01-01

The LYMAN FUSE mission concept for far ultraviolet astronomy is presented. The wavelength window from 100 to 1200 A provides access to a wide range of important scientific problems in cosmology, galactic structure, stellar evolution, and planetary magnetospheres, which cannot be studied in any other way. The LYMAN FUSE Phase A study is examining in detail mission operations, instrumentation technology, the construction of the instrument module, and the interfaces between the Instrument Module and the Explorer Platform Mission. Most of the mission observing time will be allotted through a competitive Guest Observer program analogous to that in operation for the IUE.

The Extreme Ultraviolet Explorer mission - Instrumentation and science goals

NASA Technical Reports Server (NTRS)

Bowyer, Stuart; Malina, Roger F.; Marshall, Herman L.

1988-01-01

NASA's Extreme Ultraviolet Explorer (EUVE) will carry out an all-sky survey from 80 to 800A in four bandpasses. It is expected that many types of sources will be detected, including white dwarfs and late type stars. A deep survey will also be carried out along the ecliptic which will have a limiting sensitivity a factor of 10 better than the all-sky survey in the bandpass from 80 to 300A. The payload includes a spectrometer to observe the brigher sources found in the surveys with a spectral resolution of 1 to 2A.

Icy Saturnian satellites: Disk-integrated UV-IR characteristics and links to exogenic processes

NASA Astrophysics Data System (ADS)

Hendrix, Amanda R.; Filacchione, Gianrico; Paranicas, Chris; Schenk, Paul; Scipioni, Francesca

2018-01-01

Combined Cassini observations obtained at similar observing geometries in the ultraviolet through infrared spectral range, along with additional ultraviolet (UV) data from Hubble Space Telescope where available, are used to study system-wide trends in spectral albedos of the inner icy Saturnian satellites (Mimas, Enceladus, Tethys, Dione, Rhea). We derive UV and visible geometric albedos and UV absorption strengths of the leading and trailing hemispheres and compare with E ring grain flux and charged particle intensities (electrons and ions of varying energies) to those hemispheres. We find that the UV absorption strength on the leading and trailing hemispheres is anti-correlated with E ring grain flux. On the trailing hemispheres, the UV absorption strength is correlated with intensity of electrons in the tens of keV range. We suggest that these relationships could imply links with the organic component of the E ring. Radiolytic processing of organics causes the products to become spectrally redder, increasing the UV absorption strength. Such processing occurs while organic-rich grains are in the E ring, and increases with exposure time in the E ring, such that grains interacting with Rhea are redder (more processed) than those impacting moons closer to Enceladus. Further processing (and associated darkening/reddening) occurs on the trailing hemispheres of the satellites, via radiolysis by electrons in the tens of keV range. Silicates and salts also redden with weathering; however because organics are present in the E ring in significantly greater abundance than salts or silicates, we suggest here that weathering of organics dominates the coloring of the inner Saturnian moons.

Post-Launch Calibration and Testing of Space Weather Instruments on GOES-R Satellite

NASA Technical Reports Server (NTRS)

Tadikonda, Sivakumara S. K.; Merrow, Cynthia S.; Kronenwetter, Jeffrey A.; Comeyne, Gustave J.; Flanagan, Daniel G.; Todirita, Monica

2016-01-01

The Geostationary Operational Environmental Satellite - R (GOES-R) is the first of a series of satellites to be launched, with the first launch scheduled for October 2016. The three instruments - Solar Ultra Violet Imager (SUVI), Extreme ultraviolet and X-ray Irradiance Sensor (EXIS), and Space Environment In-Situ Suite (SEISS) provide the data needed as inputs for the product updates National Oceanic and Atmospheric Administration (NOAA) provides to the public. SUVI is a full-disk extreme ultraviolet imager enabling Active Region characterization, filament eruption, and flare detection. EXIS provides inputs to solar backgrounds/events impacting climate models. SEISS provides particle measurements over a wide energy-and-flux range that varies by several orders of magnitude and these data enable updates to spacecraft charge models for electrostatic discharge. EXIS and SEISS have been tested and calibrated end-to-end in ground test facilities around the United States. Due to the complexity of the SUVI design, data from component tests were used in a model to predict on-orbit performance. The ground tests and model updates provided inputs for designing the on-orbit calibration tests. A series of such tests have been planned for the Post-Launch Testing (PLT) of each of these instruments, and specific parameters have been identified that will be updated in the Ground Processing Algorithms, on-orbit parameter tables, or both. Some of SUVI and EXIS calibrations require slewing them off the Sun, while no such maneuvers are needed for SEISS. After a six-month PLT period the GOES-R is expected to be operational. The calibration details are presented in this paper.

User's guide for the Solar Backscattered Ultraviolet (SBUV) instrument first year ozone-S data set

NASA Technical Reports Server (NTRS)

Fleig, A. J.; Klenk, K. F.; Bhartia, P. K.; Gordon, D.; Schneider, W. H.

1982-01-01

Total-ozone and ozone vertical profile results for Solar Backscattered Ultraviolet/Total Ozone Mapping Spectrometer (SBUV/TOMS) Nimbus 7 operation from November 1978 to November 1979 are available. The algorithm used have been thoroughly tested, the instrument performance has been examined in details, and the ozone results have been compared with Dobson, Umkehr, balloon, and rocket observations. The accuracy and precision of the satellite ozone data are good to at least within the ability of the ground truth to check and are self-consistent to within the specifications of the instrument. The 'SBUV User's Guide' describes the SBUV experiment and algorithms used. Detailed information on the data available on computer tape is provided including how to order tapes from the National Space Science Data Center.

GOES-R SUVI EUV Flatfields Generated Using Boustrophedon Scans

NASA Astrophysics Data System (ADS)

Shing, L.; Edwards, C.; Mathur, D.; Vasudevan, G.; Shaw, M.; Nwachuku, C.

2017-12-01

The Solar Ultraviolet Imager (SUVI) is mounted on the Solar Pointing Platform (SPP) of the Geostationary Operational Environmental Satellite, GOES-R. SUVI is a Generalized Cassegrain telescope with a large field of view that employs multilayer coatings optimized to operate in six extreme ultraviolet (EUV) narrow bandpasses centered at 9.4, 13.1, 17.1, 19.5, 28.4 and 30.4 nm. The SUVI CCD flatfield response was determined using two different techniques; The Kuhn-Lin-Lorentz (KLL) Raster and a new technique called, Dynamic Boustrophedon Scans. The new technique requires less time to collect the data and is also less sensitive to Solar features compared with the KLL method. This paper presents the flatfield results of the SUVI using this technique during Post Launch Testing (PLT).

LRO-LAMP observations of the LCROSS impact plume.

PubMed

Gladstone, G Randall; Hurley, Dana M; Retherford, Kurt D; Feldman, Paul D; Pryor, Wayne R; Chaufray, Jean-Yves; Versteeg, Maarten; Greathouse, Thomas K; Steffl, Andrew J; Throop, Henry; Parker, Joel Wm; Kaufmann, David E; Egan, Anthony F; Davis, Michael W; Slater, David C; Mukherjee, Joey; Miles, Paul F; Hendrix, Amanda R; Colaprete, Anthony; Stern, S Alan

2010-10-22

On 9 October 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) sent a kinetic impactor to strike Cabeus crater, on a mission to search for water ice and other volatiles expected to be trapped in lunar polar soils. The Lyman Alpha Mapping Project (LAMP) ultraviolet spectrograph onboard the Lunar Reconnaissance Orbiter (LRO) observed the plume generated by the LCROSS impact as far-ultraviolet emissions from the fluorescence of sunlight by molecular hydrogen and carbon monoxide, plus resonantly scattered sunlight from atomic mercury, with contributions from calcium and magnesium. The observed light curve is well simulated by the expansion of a vapor cloud at a temperature of ~1000 kelvin, containing ~570 kilograms (kg) of carbon monoxide, ~140 kg of molecular hydrogen, ~160 kg of calcium, ~120 kg of mercury, and ~40 kg of magnesium.

Detail of Triton's Surface

NASA Technical Reports Server (NTRS)

1989-01-01

This color photo of Neptune's large satellite Triton was obtained on Aug. 24 1989 at a range of 530,000 kilometers(330,000 miles). The resolution is about 10 kilometers (6.2 miles), sufficient to begin to show topographic detail. The image was made from pictures taken through the green, violet and ultraviolet filters. In this technique, regions that are highly reflective in the ultraviolet appear blue in color. In reality, there is no part of Triton that would appear blue to the eye. The bright southern hemisphere of Triton, which fills most of this frame, is generally pink in tone as is the even brighter equatorial band. The darker regions north of the equator also tend to be pink or reddish in color.

JPL manages the Voyager project for NASA's Office of Space Science.

Far Ultraviolet Imaging from the Image Spacecraft

NASA Technical Reports Server (NTRS)

Mende, S. B.; Heetderks, H.; Frey, H. U.; Lampton, M.; Geller, S. P.; Stock, J. M.; Abiad, R.; Siegmund, O. H. W.; Tremsin, A. S.; Habraken, S.

2000-01-01

Direct imaging of the magnetosphere by the IMAGE spacecraft will be supplemented by observation of the global aurora. The IMAGE satellite instrument complement includes three Far Ultraviolet (FUV) instruments. The Wideband Imaging Camera (WIC) will provide broad band ultraviolet images of the aurora for maximum spatial and temporal resolution by imaging the LBH N2 bands of the aurora. The Spectrographic Imager (SI), a novel form of monochromatic imager, will image the aurora, filtered by wavelength. The proton-induced component of the aurora will be imaged separately by measuring the Doppler-shifted Lyman-a. Finally, the GEO instrument will observe the distribution of the geocoronal emission to obtain the neutral background density source for charge exchange in the magnetosphere. The FUV instrument complement looks radially outward from the rotating IMAGE satellite and, therefore, it spends only a short time observing the aurora and the Earth during each spin. To maximize photon collection efficiency and use efficiently the short time available for exposures the FUV auroral imagers WIC and SI both have wide fields of view and take data continuously as the auroral region proceeds through the field of view. To minimize data volume, the set of multiple images are electronically co-added by suitably shifting each image to compensate for the spacecraft rotation. In order to minimize resolution loss, the images have to be distort ion-corrected in real time. The distortion correction is accomplished using high speed look up tables that are pre-generated by least square fitting to polynomial functions by the on-orbit processor. The instruments were calibrated individually while on stationary platforms, mostly in vacuum chambers. Extensive ground-based testing was performed with visible and near UV simulators mounted on a rotating platform to emulate their performance on a rotating spacecraft.

Perception via satellite

USGS Publications Warehouse

Robinove, Charles J.

1970-01-01

The earth resources observation satellite (EROS) program in the Department of the Interior is intended to gather and use data from satellites and aircraft on natural and man-made features of the earth's surface. Earth resources technology satellite will provide the EROS program with data for use in dealing with natural resource problems and understanding the interaction between man and the environment. Applications will include studies of tectonic features, hydrologic problems, location of fish schools, determination of the conditions of range land, mapping land use for urban planning, studies of erosion and change along coastlines and major streams, and inventories of land use and land forms. In addition, the ERTS data may be used for detecting forest and crop diseases and inventorying crops. The ERTS satellite will be in a polar, sun-synchronous orbit so that each point on the earth's surface will be sensed every 17 to 20 days, at the same time of day. Multispectral photography is being investigated for its usefulness in hydrology. Side-looking airborne radar has not yet been widely used in hydrologic studies, although it is an excellent tool for all-weather, day or night, coverage of large areas. Other techniques being investigated include passive microwave radiometry, ultraviolet and visible stimulated luminescence, and absorption spectroscopy.

The spectral energy distribution of Zeta Puppis and HD 50896

NASA Technical Reports Server (NTRS)

Holm, A. V.; Cassinelli, J. P.

1977-01-01

The ultraviolet spectral energy distribution of the O5f star Zeta Pup and the WN5 star HD 50896 are derived from OAO-2 observations with the calibration of Bless, Code, and Fairchild (1976). An estimate of the interstellar reddening (0.12 magnitude) of the Wolf-Rayet star is determined from the size of the characteristic interstellar extinction bump at 4.6 inverse microns. After correction for extinction, both stars show a flat energy distribution in the ultraviolet. The distribution of HD 50896 from 1100 A to 2 microns is in good agreement with results of extended model atmospheres, but some uncertainty remains because of the interstellar-extinction correction. The absolute energy distribution of Zeta Pup is fitted by a 42,000-K plane-parallel model if the model's flux is adjusted for the effects of electron scattering in the stellar wind and for UV line blanketing that was determined empirically from high-resolution Copernicus satellite observations. To achieve this fit, it is necessary to push both the spectroscopically determined temperature and the ultraviolet calibration to the limits of their probable errors.

First results from the TUS orbital detector in the extensive air shower mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khrenov, B.A.; Klimov, P.A.; Panasyuk, M.I.

TUS (Tracking Ultraviolet Set-up), the first orbital detector of extreme energy cosmic rays (EECRs), those with energies above 50 EeV, was launched into orbit on April 28, 2016, as a part of the Lomonosov satellite scientific payload. The main aim of the mission is to test a technique of registering fluorescent and Cherenkov radiation of extensive air showers generated by EECRs in the atmosphere with a space telescope. We present preliminary results of its operation in a mode dedicated to registering extensive air showers in the period from August 16, 2016, to November 4, 2016. No EECRs have been conclusivelymore » identified in the data yet, but the diversity of ultraviolet emission in the atmosphere was found to be unexpectedly rich. We discuss typical examples of data obtained with TUS and their possible origin. The data is important for obtaining more accurate estimates of the nocturnal ultraviolet glow of the atmosphere, necessary for successful development of more advanced orbital EECR detectors including those of the KLYPVE (K-EUSO) and JEM-EUSO missions.« less

New Observations of Molecular Nitrogen by the Imaging Ultraviolet Spectrograph on MAVEN

NASA Astrophysics Data System (ADS)

Stevens, Michael H.; Evans, J. S.; Schneider, Nicholas M.; Stewart, A. I. F.; Deighan, Justin; Jain, Sonal K.; Crismani, Matteo M. J.; Stiepen, Arnaud; Chaffin, Michael S.; McClintock, William E.; Holsclaw, Greg M.; Lefevre, Franck; Montmessin, Franck; Lo, Daniel Y.; Clarke, John T.; Bougher, Stephen W.; Jakosky, Bruce M.

2015-11-01

The Martian ultraviolet dayglow provides information on the basic state of the Martian upper atmosphere. The Imaging Ultraviolet Spectrograph (IUVS) on NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has observed Mars at mid and far-UV wavelengths since its arrival in September 2014. In this work, we describe a linear regression method used to extract components of UV spectra from IUVS limb observations and focus in particular on molecular nitrogen (N2) photoelectron excited emissions. We identify N2 Lyman-Birge-Hopfield (LBH) emissions for the first time at Mars and we also confirm the tentative identification of N2 Vegard-Kaplan (VK) emissions. We compare observed VK and LBH limb radiance profiles to model results between 90 and 210 km. Finally, we compare retrieved N2 density profiles to general circulation (GCM) model results. Contrary to earlier analyses using other satellite data that indicated N2 densities were a factor of three less than predictions, we find that N2 abundances exceed GCM results by about a factor of two at 130 km but are in agreement at 150 km.

The first Extreme Ultraviolet Explorer source catalog

NASA Technical Reports Server (NTRS)

Bowyer, S.; Lieu, R.; Lampton, M.; Lewis, J.; Wu, X.; Drake, J. J.; Malina, R. F.

1994-01-01

The Extreme Ultraviolet Explorer (EUVE) has conducted an all-sky survey to locate and identify point sources of emission in four extreme ultraviolet wavelength bands centered at approximately 100, 200, 400, and 600 A. A companion deep survey of a strip along half the ecliptic plane was simultaneously conducted. In this catalog we report the sources found in these surveys using rigorously defined criteria uniformly applied to the data set. These are the first surveys to be made in the three longer wavelength bands, and a substantial number of sources were detected in these bands. We present a number of statistical diagnostics of the surveys, including their source counts, their sensitivites, and their positional error distributions. We provide a separate list of those sources reported in the EUVE Bright Source List which did not meet our criteria for inclusion in our primary list. We also provide improved count rate and position estimates for a majority of these sources based on the improved methodology used in this paper. In total, this catalog lists a total of 410 point sources, of which 372 have plausible optical ultraviolet, or X-ray identifications, which are also listed.

Extended and refined multi sensor reanalysis of total ozone for the period 1970-2012

NASA Astrophysics Data System (ADS)

van der A, R. J.; Allaart, M. A. F.; Eskes, H. J.

2015-07-01

The ozone multi-sensor reanalysis (MSR) is a multi-decadal ozone column data record constructed using all available ozone column satellite data sets, surface Brewer and Dobson observations and a data assimilation technique with detailed error modelling. The result is a high-resolution time series of 6-hourly global ozone column fields and forecast error fields that may be used for ozone trend analyses as well as detailed case studies. The ozone MSR is produced in two steps. First, the latest reprocessed versions of all available ozone column satellite data sets are collected and then are corrected for biases as a function of solar zenith angle (SZA), viewing zenith angle (VZA), time (trend), and stratospheric temperature using surface observations of the ozone column from Brewer and Dobson spectrophotometers from the World Ozone and Ultraviolet Radiation Data Centre (WOUDC). Subsequently the de-biased satellite observations are assimilated within the ozone chemistry and data assimilation model TMDAM. The MSR2 (MSR version 2) reanalysis upgrade described in this paper consists of an ozone record for the 43-year period 1970-2012. The chemistry transport model and data assimilation system have been adapted to improve the resolution, error modelling and processing speed. Backscatter ultraviolet (BUV) satellite observations have been included for the period 1970-1977. The total record is extended by 13 years compared to the first version of the ozone multi sensor reanalysis, the MSR1. The latest total ozone retrievals of 15 satellite instruments are used: BUV-Nimbus4, TOMS-Nimbus7, TOMS-EP, SBUV-7, -9, -11, -14, -16, -17, -18, -19, GOME, SCIAMACHY, OMI and GOME-2. The resolution of the model runs, assimilation and output is increased from 2° × 3° to 1° × 1°. The analysis is driven by 3-hourly meteorology from the ERA-Interim reanalysis of the European Centre for Medium-Range Weather Forecasts (ECMWF) starting from 1979, and ERA-40 before that date. The chemistry parameterization has been updated. The performance of the MSR2 analysis is studied with the help of observation-minus-forecast (OmF) departures from the data assimilation, by comparisons with the individual station observations and with ozone sondes. The OmF statistics show that the mean bias of the MSR2 analyses is less than 1 % with respect to de-biased satellite observations after 1979.

JPL-20180131-EXPLORs-0001- 60th Anniversary Explorer 1 The Beginning of the US Space Program

NASA Image and Video Library

2018-01-31

Flashback to Jan. 31, 1958, the day a rocket carrying a javelin-shaped satellite took flight into space. Explorer 1 was America's first satellite. Here's a look back at the beginning of the Space Age.

Compact autonomous navigation system (CANS)

NASA Astrophysics Data System (ADS)

Hao, Y. C.; Ying, L.; Xiong, K.; Cheng, H. Y.; Qiao, G. D.

2017-11-01

Autonomous navigation of Satellite and constellation has series of benefits, such as to reduce operation cost and ground station workload, to avoid the event of crises of war and natural disaster, to increase spacecraft autonomy, and so on. Autonomous navigation satellite is independent of ground station support. Many systems are developed for autonomous navigation of satellite in the past 20 years. Along them American MANS (Microcosm Autonomous Navigation System) [1] of Microcosm Inc. and ERADS [2] [3] (Earth Reference Attitude Determination System) of Honeywell Inc. are well known. The systems anticipate a series of good features of autonomous navigation and aim low cost, integrated structure, low power consumption and compact layout. The ERADS is an integrated small 3-axis attitude sensor system with low cost and small volume. It has the Earth center measurement accuracy higher than the common IR sensor because the detected ultraviolet radiation zone of the atmosphere has a brightness gradient larger than that of the IR zone. But the ERADS is still a complex system because it has to eliminate many problems such as making of the sapphire sphere lens, birefringence effect of sapphire, high precision image transfer optical fiber flattener, ultraviolet intensifier noise, and so on. The marginal sphere FOV of the sphere lens of the ERADS is used to star imaging that may be bring some disadvantages., i.e. , the image energy and attitude measurements accuracy may be reduced due to the tilt image acceptance end of the fiber flattener in the FOV. Besides Japan, Germany and Russia developed visible earth sensor for GEO [4] [5]. Do we have a way to develop a cheaper/easier and more accurate autonomous navigation system that can be used to all LEO spacecraft, especially, to LEO small and micro satellites? To return this problem we provide a new type of the system—CANS (Compact Autonomous Navigation System) [6].

Evaluating Ultraviolet Radiation Exposures Determined from TOMS Satellite Data at Sites of Amphibian Declines in Central and South America

NASA Technical Reports Server (NTRS)

Middleton, Elizabeth M.; Smith, David E. (Technical Monitor)

2000-01-01

Many amphibian species have experienced substantial population declines, or have disappeared altogether, during the last several decades at a number of amphibian census sites in Central and South America. This study addresses the use of satellite-derived trends in solar ultraviolet-B (UV-B; 280-320 nm) radiation exposures at these sites over the last two decades, and is intended to demonstrate a role for satellite observations in determining whether UV-B radiation is a contributing factor in amphibian declines. UV-B radiation levels at the Earth's surface were derived from the Total Ozone Mapping Spectrometer (TOMS) satellite data, typically acquired daily since 1979. These data were used to calculate the daily erythemal (sunburning) UV-B, or UV-B(sub ery), exposures at the latitude, longitude, and elevation of each of 20 census sites. The annually averaged UV-B(sub ery) dose, as well as the maximum values, have been increasing in both Central and South America, with higher levels received at the Central American sites. The annually averaged UV-B(sub ery) exposures increased significantly from 1979-1998 at all 11 Central American sites examined (r(exp 2) = 0.60 - 0.79; P<=0.015), with smaller but significant increases at five of the nine South American sites (r(exp 2) = 0.24-0.42; P<=0.05). The contribution of the highest UV-B(sub ery) exposure levels (>= 6750 J/sq m*d) to the annual UV-B(sub ery) total has increased from approx. 5% to approx. 15% in Central America over the 19 year period, but actual daily exposures for each species are unknown. Synergy among UV-B radiation and other factors, especially those associated with alterations of water chemistry (e.g., acidification) in aqueous habitats is discussed. These findings justify further research concerning whether UV-B(sub ery) radiation plays a role in amphibian population declines and extinctions.

IRAS observations of the Pleiades

NASA Technical Reports Server (NTRS)

Cox, P.; he ultraviolet.

1987-01-01

The Infrared Astronomy Satellite (IRAS) observations of the Pleiades region are reported. The data show large flux densities at 12 and 25 microns, extended over the optical nebulosity. This strong excess emission, implying temperatures of a few hundred degrees Kelvin, indicates a population of very small grains in the Pleiades. It is suggested that these grains are similar to the small grains needed to explain the surface brightness measurements made in the ultraviolet.

The Gum nebula and related problems

NASA Technical Reports Server (NTRS)

Maran, S. P.; Brandt, J. C.; Stecher, T. P.

1971-01-01

Papers were presented in conference sessions on the Gum nebula, the Vela X remnant, the hot stars gamma Velorum and zeta Puppis, the B associations in the Vela-Puppis complex, and pulsars. Ground-based optical and radio astronomy; rocket and satellite observations in the radio, visible, ultraviolet, and X-ray regions; and theoretical problems in the physical state of the interstellar medium, stellar evolution, and runaway star dynamics were considered.

Retrieval Of Cloud Pressure And Chlorophyll Content Using Raman Scattering In GOME Ultraviolet Spectra

NASA Technical Reports Server (NTRS)

Atlas, Robert (Technical Monitor); Joiner, Joanna; Vasikov, Alexander; Flittner, David; Gleason, James; Bhartia, P. K.

2002-01-01

Reliable cloud pressure estimates are needed for accurate retrieval of ozone and other trace gases using satellite-borne backscatter ultraviolet (buv) instruments such as the global ozone monitoring experiment (GOME). Cloud pressure can be derived from buv instruments by utilizing the properties of rotational-Raman scattering (RRS) and absorption by O2-O2. In this paper we estimate cloud pressure from GOME observations in the 355-400 nm spectral range using the concept of a Lambertian-equivalent reflectivity (LER) surface. GOME has full spectral coverage in this range at relatively high spectral resolution with a very high signal-to-noise ratio. This allows for much more accurate estimates of cloud pressure than were possible with its predecessors SBUV and TOMS. We also demonstrate the potential capability to retrieve chlorophyll content with full-spectral buv instruments. We compare our retrieved LER cloud pressure with cloud top pressures derived from the infrared ATSR instrument on the same satellite. The findings confirm results from previous studies that showed retrieved LER cloud pressures from buv observations are systematically higher than IR-derived cloud-top pressure. Simulations using Mie-scattering radiative transfer algorithms that include O2-O2 absorption and RRS show that these differences can be explained by increased photon path length within and below cloud.

Ionospheric-thermospheric UV tomography: 2. Comparison with incoherent scatter radar measurements

NASA Astrophysics Data System (ADS)

Dymond, K. F.; Nicholas, A. C.; Budzien, S. A.; Stephan, A. W.; Coker, C.; Hei, M. A.; Groves, K. M.

2017-03-01

The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors that fly on the Defense Meteorological Satellite Program F16-F19 satellites. The SSULIs cover the 80-170 nm wavelength range which contains emissions at 91 and 136 nm, which are produced by radiative recombination of the ionosphere. We invert the 91.1 nm emission tomographically using a newly developed algorithm that includes optical depth effects due to pure absorption and resonant scattering. We present the details of our approach including how the optimal altitude and along-track sampling were determined and the newly developed approach we are using for regularizing the SSULI tomographic inversions. Finally, we conclude with validations of the SSULI inversions against Advanced Research Project Agency Long-range Tracking and Identification Radar (ALTAIR) incoherent scatter radar measurements and demonstrate excellent agreement between the measurements. As part of this study, we include the effects of pure absorption by O2, N2, and O in the inversions and find that best agreement between the ALTAIR and SSULI measurements is obtained when only O2 and O are included, but the agreement degrades when N2 absorption is included. This suggests that the absorption cross section of N2 needs to be reinvestigated near 91.1 nm wavelengths.

Antarctic Ultraviolet Radiation Climatology from Total Ozone Mapping Spectrometer Data

NASA Technical Reports Server (NTRS)

Lubin, Dan

2004-01-01

This project has successfully produced a climatology of local noon spectral surface irradiance covering the Antarctic continent and the Southern Ocean, the spectral interval 290-700 nm (UV-A, UV-B, and photosynthetically active radiation, PAR), and the entire sunlit part of the year for November 1979-December 1999. Total Ozone Mapping Spectrometer (TOMS) data were used to specify column ozone abundance and UV-A (360- or 380-nm) reflectivity, and passive microwave (MW) sea ice concentrations were used to specify the surface albedo over the Southern Ocean. For this latter task, sea ice concentration retrievals from the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and its successor, the Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I) were identified with ultraviolet/visible-wavelength albedos based on an empirical TOMS/MW parameterization developed for this purpose (Lubin and Morrow, 2001). The satellite retrievals of surface albedo and UV-A reflectivity were used in a delta-Eddington radiative transfer model to estimate cloud effective optical depth. These optical depth estimates were then used along with the total ozone and surface albedo to calculate the downwelling spectral UV and PAR irradiance at the surface. These spectral irradiance maps were produced for every usable day of TOMS data between 1979-1999 (every other day early in the TOMS program, daily later on).

A Fourier transform spectrometer for visible and near ultra-violet measurements of atmospheric absorption

NASA Technical Reports Server (NTRS)

Parsons, C. L.; Gerlach, J. C.; Whitehurst, M.

1982-01-01

The development of a prototype, ground-based, Sun-pointed Michelson interferometric spectrometer is described. Its intended use is to measure the atmospheric amount of various gases which absorb in the near-infrared, visible, and near-ultraviolet portions of the electromagnetic spectrum. Preliminary spectra which contain the alpha, 0.8 micrometer, and rho sigma tau water vapor absorption bands in the near-infrared are presented to indicate the present capability of the system. Ultimately, the spectrometer can be used to explore the feasible applications of Fourier transform spectroscopy in the ultraviolet where grating spectrometers were used exclusively.

EUVE GO Survey: High Levels of User Satisfaction

NASA Astrophysics Data System (ADS)

Stroozas, B. A.

2000-12-01

This paper describes the results of a detailed customer survey of Guest Observers (GOs) for NASA's Extreme Ultraviolet Explorer (EUVE) astronomy satellite observatory. The purpose of the research survey was to (1) measure the levels of GO customer satisfaction with respect to EUVE observing services, and (2) compare the observing experiences of EUVE GOs with their experiences using other satellite observatories. This survey was conducted as a business research project -- part of the author's graduate work as an MBA candidate. A total sample of 38 respondents, from a working population of 101 "active" EUVE GOs, participated in this survey. The results, which provided a profile of the "typical" EUVE GO, showed in a statistically significant fashion that these GOs were more than satisfied with the available EUVE observing services. In fact, the sample GOs generally rated their EUVE observing experiences to be better than average as compared to their experiences as GOs on other missions. These relatively high satisfaction results are particularly pleasing to the EUVE Project which, given its significantly reduced staffing environment at U.C. Berkeley, has continued to do more with less. This paper outlines the overall survey process: the relevant background and previous research, the survey design and methodology, and the final results and their interpretation. The paper also points out some general limitations and weaknesses of the study, along with some recommended actions for the EUVE Project and for NASA in general. This work was funded by NASA/UCB Cooperative Agreement NCC5-138.

Spacelab

NASA Image and Video Library

1989-01-01

In 1986, NASA introduced a Shuttle-borne ultraviolet observatory called Astro. The Astro Observatory was designed to explore the universe by observing and measuring the ultraviolet radiation from celestial objects. Astronomical targets of observation selected for Astro missions included planets, stars, star clusters, galaxies, clusters of galaxies, quasars, remnants of exploded stars (supernovae), clouds of gas and dust (nebulae), and the interstellar medium. Astro-1 used a Spacelab pallet system with an instrument pointing system and a cruciform structure for bearing the three ultraviolet instruments mounted in a parallel configuration. The three instruments were: The Hopkins Ultraviolet Telescope (HUT), which was designed to obtain far-ultraviolet spectroscopic data from white dwarfs, emission nebulae, active galaxies, and quasars; the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) which was to study polarized ultraviolet light from magnetic white dwarfs, binary stars, reflection nebulae, and active galaxies; and the Ultraviolet Imaging Telescope (UIT) which was to record photographic images in ultraviolet light of galaxies, star clusters, and nebulae. The star trackers that supported the instrument pointing system were also mounted on the cruciform. Also in the payload bay was the Broad Band X-Ray Telescope (BBXRT), which was designed to obtain high-resolution x-ray spectra from stellar corona, x-ray binary stars, active galactic nuclei, and galaxy clusters. Managed by the Marshall Space Flight Center, the Astro-1 observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

Minuteman 2 launched small satellite

NASA Technical Reports Server (NTRS)

Chan, Sunny; Hinders, Kriss; Martin, Trent; Mcmillian, Shandy; Sharp, Brad; Vajdos, Greg

1994-01-01

The goal of LEOSat Industries' Spring 1994 project was to design a small satellite that has a strong technology demonstration or scientific justification and incorporates a high level of student involvement. The satellite is to be launched into low earth orbit by the converted Minuteman 2 satellite launcher designed by Minotaur Designs, Inc. in 1993. The launch vehicle shroud was modified to a height of 90 inches, a diameter of 48 inches at the bottom and 35 inches at the top for a total volume of 85 cubic feet. The maximum allowable mass of the payload is about 1100 lb., depending on the launch site, orbit altitude, and inclination. The satellite designed by LEOSat Industries is TerraSat, a remote-sensing satellite that will provide information for use in space-based earth studies. It will consist of infrared and ultraviolet/visible sensors similar to the SDI-developed sensors being tested on Clementine. The sensors will be mounted on the Defense Systems, Inc. Standard Satellite-1 spacecraft bus. LEOSat has planned for two satellites orbiting the Earth with trajectories similar to that of LANDSAT 5. The semi-major axis is 7080 kilometers, the eccentricity is 0, and the inclination is 98.2 degrees. The estimated mass of TerraSat is 145 kilograms and the estimated volume is 1.8 cubic meters. The estimated cost of TerraSat is $13.7 million. The projected length of time from assembly of the sensors to launch of the spacecraft is 13 months.

Global Characteristics of the Correlation and Time Lag Between Solar and Ionospheric Parameters in the 27-day Period

NASA Technical Reports Server (NTRS)

Lee, Choon-Ki; Han, Shin-Chan; Dieter,Bilitza; Ki-Weon,Seo

2012-01-01

The 27-day variations of topside ionosphere are investigated using the in-situ electron density measurements from the CHAMP planar Langmuir probe and GRACE K-band ranging system. As the two satellite systems orbit at the altitudes of approx. 370 km and approx. 480 km, respectively, the satellite data sets are greatly valuable for examining the electron density variations in the vicinity of F2-peak. In a 27-day period, the electron density measurements from the satellites are in good agreements with the solar flux, except during the solar minimum period. The time delays are mostly 1-2 day and represent the hemispherical asymmetry. The globally-estimated spatial patterns of the correlation between solar flux and in-situ satellite measurements show poor correlations in the (magnetic) equatorial region, which are not found from the ground measurements of vertically-integrated electron content. We suggest that the most plausible cause for the poor correlation is the vertical movement of ionization due to atmospheric dynamic processes that is not controlled by the solar extreme ultraviolet radiation.

Astro-1 Image Taken by Ultraviolet Imaging Telescope

NASA Technical Reports Server (NTRS)

1990-01-01

This image shows a part of the Cygnus loop supernova remnant, taken by the Ultraviolet Imaging Telescope (UIT) on the Astro Observatory during the Astro-1 mission (STS-35) on December 5, 1990. Pictured is a portion of the huge Cygnus loop, an array of interstellar gas clouds that have been blasted by a 900,000 mile per hour shock wave from a prehistoric stellar explosion, which occurred about 20,000 years ago, known as supernova. With ultraviolet and x-rays, astronomers can see emissions from extremely hot gases, intense magnetic fields, and other high-energy phenomena that more faintly appear in visible and infrared light or in radio waves that are crucial to deepening the understanding of the universe. The Astro Observatory was designed to explore the universe by observing and measuring the ultraviolet radiation from celestial objects. Three instruments make up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had managment responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

TOPEX satellite concept. TOPEX option study report

NASA Technical Reports Server (NTRS)

Meyer, D. P.; Case, C. M.

1982-01-01

Candidate bus equipment from the Viking, Applications Explorer Mission, and Small Scientific Satellite programs for application to the TOPEX mission options is assessed. Propulsion module equipment and subsystem candidates from the Applications Explorer Mission satellites and the Small Scientific Satellite spacecraft are evaluated for those TOPEX options. Several subsystem concepts appropriate to the TOPEX options are described. These descriptions consider performance characteristics of the subsystems. Cost and availability information on the candidate equipment and subsystems are also provided.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Tori McLendon of NASA Communications, speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Explorer 1 60th Anniversary

NASA Image and Video Library

2018-01-31

Kennedy Space Center Director Bob Cabana speaks to guests at an event celebrating the 60th anniversary of America's first satellite. The ceremony took place in front of the Space Launch Complex 26 blockhouse at Cape Canaveral Air Force Station where the Explorer 1 satellite was launched atop a Jupiter C rocket on Jan. 31, 1958. During operation, the satellite's cosmic ray detector discovered radiation belts around Earth which were named for Dr. James Van Allen, principal investigator for the satellite.

Thermal analyses of the International Ultraviolet Explorer (IUE) scientific instrument using the NASTRAN thermal analyzer (NTA): A general purpose summary

NASA Technical Reports Server (NTRS)

Jackson, C. E., Jr.

1976-01-01

The NTA Level 15.5.2/3, was used to provide non-linear steady-state (NLSS) and non-linear transient (NLTR) thermal predictions for the International Ultraviolet Explorer (IUE) Scientific Instrument (SI). NASTRAN structural models were used as the basis for the thermal models, which were produced by a straight forward conversion procedure. The accuracy of this technique was sub-sequently demonstrated by a comparison of NTA predicts with the results of a thermal vacuum test of the IUE Engineering Test Unit (ETU). Completion of these tasks was aided by the use of NTA subroutines.

Thermal design of the IUE hydrazine auxiliary propulsion system. [International Ultraviolet Explorer

NASA Technical Reports Server (NTRS)

Skladany, J. T.; Kelly, W. H.

1977-01-01

The International Ultraviolet Explorer is a large astronomical observatory scheduled to be placed in a three-axis stabilized synchronous orbit in the fourth quarter of 1977. The Hydrazine Auxiliary Propulsion System (HAPS) must perform a number of spacecraft maneuvers to achieve a successful mission. This paper describes the thermal design which accomplishes temperature control between 5 and 65 C for all orbital conditions by utilizing multilayer insulation and commandable component heaters. A primary design criteria was the minimization of spacecraft power by the selective use of the solar environment. The thermal design was carefully assessed and verified in both spacecraft thermal balance and subsystem solar simulation testing.

An overview of the extreme ultraviolet explorer and its scientific program

NASA Technical Reports Server (NTRS)

Malina, Roger F.; Finley, David S.; Jelinsky, Patrick; Vallerga, John; Bowyer, Stuart

1987-01-01

NASA's Extreme Ultraviolet Explorer (EUVE) will carry out an all-sky survey from 8 to 90 nm in four bandpasses; the limiting sensitivity will be between 2 to 3 orders of magnitude fainter than the hot white dwarf HZ 43. A deep survey will also be carried out along the ecliptic which will have a limiting sensitivity of 1 to 2 orders of magnitude fainter than the all-sky survey in the bandpass from 8 to 50 nm. The payload also includes a spectrometer which will be used to observe the brighter sources found in the surveys with a spectral resolution of 1 to 2 A.

EXTREME ULTRAVIOLET EXPLORER OBSERVATIONS OF HERCULES X-1 OVER A 35 DAY CYCLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leahy, D. A.; Dupuis, Jean, E-mail: leahy@ucalgary.c

2010-06-01

Observations of Hercules X-1 by the Extreme Ultraviolet Explorer covering most of the 35 day cycle are reported here. This is the only long extreme ultraviolet (EUV) observation of Her X-1. Simultaneous X-ray observations with the Rossi X-ray Timing Explorer All-Sky Monitor (RXTE/ASM) X-ray show that Her X-1 is in an X-ray anomalous low state. The first 4 days are also observed with the RXTE proportional counter array (PCA), which shows that the X-ray properties are nearly the same as for normal low states in Her X-1 with flux reduced by a factor of 2. In contrast, the EUV emissionmore » from Her X-1 is reduced by a factor of {approx}4 compared to normal low states. The twisted-tilted accretion disk responsible for the normal 35 day X-ray cycle can be modified to explain this behavior. An increased disk twist reduces the X-ray illumination of HZ Her by a factor of {approx}2 and of the disk surface by a somewhat larger factor, leading to a larger reduction in EUV flux compared to X-ray flux.« less

ULTRAVIOLET SPECTROSCOPY OF BL Hyi AND EF Eri IN HIGH AND INTERMEDIATE STATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanad, M. R.; Abdel-Sabour, M. A.

2016-08-01

We present the first phase-resolved ultraviolet spectroscopy of two polar systems, BL Hyi and EF Eri, in high and intermediate states from the International Ultraviolet Explorer ( IUE ) during the periods between 1982–1995 and 1979–1991, respectively. The flux curves for the C iv and He ii emission lines for both systems showing variations in their fluxes at different orbital phases are presented. The emission lines are produced in the accretion stream. The reddening for the two polars is found to be 0.00. Our results show that there are variations of the line fluxes with time, similar to the lightmore » curves found for both BL Hyi and EF Eri in the optical, infrared, ultraviolet, and X-ray bands. IUE observations support a radiative shock model of BL Hyi with the heating of matter by radiation from the accretion shock and cooling by the electrons scattering off ultraviolet photons from the surface of the white dwarf. EF Eri observations support a two-temperature white dwarf model producing sufficient ultraviolet flux for orbital modulations.« less

Spacelab

NASA Image and Video Library

1990-12-05

This image shows a part of the Cygnus loop supernova remnant, taken by the Ultraviolet Imaging Telescope (UIT) on the Astro Observatory during the Astro-1 mission (STS-35) on December 5, 1990. Pictured is a portion of the huge Cygnus loop, an array of interstellar gas clouds that have been blasted by a 900,000 mile per hour shock wave from a prehistoric stellar explosion, which occurred about 20,000 years ago, known as supernova. With ultraviolet and x-rays, astronomers can see emissions from extremely hot gases, intense magnetic fields, and other high-energy phenomena that more faintly appear in visible and infrared light or in radio waves that are crucial to deepening the understanding of the universe. The Astro Observatory was designed to explore the universe by observing and measuring the ultraviolet radiation from celestial objects. Three instruments make up the Astro Observatory: The Hopkins Ultraviolet Telescope (HUT), the Ultraviolet Imaging Telescope (UIT), and the Wisconsin Ultraviolet Photo-Polarimetry Experiment (WUPPE). The Marshall Space Flight Center had managment responsibilities for the Astro-1 mission. The Astro-1 Observatory was launched aboard the Space Shuttle Orbiter Columbia (STS-35) on December 2, 1990.

The University of Colorado OSO-8 spectrometer experiment. IV - Mission operations

NASA Technical Reports Server (NTRS)

Hansen, E. R.; Bruner, E. C., Jr.

1979-01-01

The remote operation of two high-resolution ultraviolet spectrometers on the OSO-8 satellite is discussed. Mission operations enabled scientific observers to plan observations based on current solar data, interact with the observing program using real- or near real-time data and commands, evaluate quick-look instrument data, and analyze the observations for publication. During routine operations, experiments were planned a day prior to their execution, and the data from these experiments received a day later. When a shorter turnaround was required, a real-time mode was available. Here, the real-time data and command links into the remote control center were used to evaluate experiment operation and make satellite pointing or instrument configuration changes with a 1-90 minute turnaround.

Ocean Raman Scattering in Satellite Backscatter UV Measurements

NASA Technical Reports Server (NTRS)

Vasilkov, Alexander P.; Joiner, Joanna; Gleason, James; Bhartia, Pawan; Bhartia, P. K. (Technical Monitor)

2002-01-01

Ocean Raman scattering significantly contributes to the filling-in of solar Fraunhofer lines measured by satellite backscatter ultraviolet (buy) instruments in the cloudless atmosphere over clear ocean waters. A model accounting for this effect in buy measurements is developed and compared with observations from the Global Ozone Monitoring Experiment (GONE). The model extends existing models for ocean Raman scattering to the UV spectral range. Ocean Raman scattering radiance is propagated through the atmosphere using a concept of the Lambert equivalent reflectively and an accurate radiative transfer model for Rayleigh scattering. The model and observations can be used to evaluate laboratory measurements of pure water absorption in the UV. The good agreement between model and observations suggests that buy instruments may be useful for estimating chlorophyll content.

Satellite observations of polar mesospheric clouds by the solar backscattered ultraviolet spectral radiometer - Evidence of a solar cycle dependence

NASA Technical Reports Server (NTRS)

Thomas, Gary E.; Mcpeters, Richard D.; Jensen, Eric J.

1991-01-01

Results are presented on eight years of satellite observations of the polar mesospheric clouds (PMCs) by the SBUV spectral radiometer, showing that PMCs occur in the summertime polar cap regions of both hemispheres and that they exhibit year-to-year variability. It was also found that the increase in the PMC occurrence frequency was inversely correlated with solar activity. Two kinds of hemispherical asymmetries could be identified: (1) PMCs in the Northern Hemisphere were significantly brighter than in the Southern Hemisphere, in accordance with previous results derived from SME data; and (2) the solar cycle response in the south is more pronounced than in the north. The paper also describes the cloud detection algorithm.

The MATS Satellite Mission - Tomographic Perspectives on the Mesosphere

NASA Astrophysics Data System (ADS)

Karlsson, B.; Gumbel, J.

2015-12-01

Tomography in combination with space-borne limb imaging opens exciting new ways of probing atmospheric structures. MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is a new Swedish satellite mission that applies these ideas to the mesosphere. MATS science questions focus on mesospheric wave activity and noctilucent clouds. Primary measurement targets are O2 Atmospheric band dayglow and nightglow in the near infrared (759-767 nm) and sunlight scattered from noctilucent clouds in the ultraviolet (270-300 nm). While tomography provides horizontally and vertically resolved data, spectroscopy allows analysis in terms of mesospheric composition, temperature and cloud properties. This poster introduces instrument and analysis ideas, and discusses scientific perspectives and connections to other missions. MATS is being prepared for a launch in 2018.

Satellite remote sensing and ozonesonde observation of ozone vertical profile and severe storm development

NASA Technical Reports Server (NTRS)

Hung, R. J.; Liu, J. M.

1988-01-01

Two year ozonesonde data, January 1981 to December 1982, observed at four Canadian stations, and two-and-a-half year backscattered ultraviolet experiment data on the Nimbus-4 satellite, April 1970 to August 1972, observed over five U.S. stations, were used to study the relationship between the total ozone, vertical distribution of the ozone mixing ratio, height of half the total ozone, and the variation of local tropopause height. In view of the correlation between the variation of the tropopause height and the possible development of severe storms, a better understanding of the effect of the vertical distribution of the local ozone profile on the variation of the tropopause height can give considerable insight into the development of severe storms.

KSC-03pd1285

NASA Image and Video Library

2003-04-28

KENNEDY SPACE CENTER, FLA. - Orbital Sciences' L-1011 aircraft takes off from Cape Canaveral Air Force Station carrying the Pegasus XL rocket/Galaxy Evolution Explorer (GALEX) under its belly. Release of the Pegasus was scheduled for about 8 a.m. over the Atlantic Ocean at an altitude of 39,000 feet at a location approximately 100 nautical miles offshore east-northeast of Cape Canaveral. Spacecraft separation from the Pegasus occurs 11 minutes later. At that time the satellite will be in a circular orbit of 431 statute miles (690 km) at a 29-degree inclination. The GALEX will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1287

NASA Image and Video Library

2003-04-28

KENNEDY SPACE CENTER, FLA. - Orbital Sciences' L-1011 aircraft takes off from Cape Canaveral Air Force Station carrying the Pegasus XL rocket/Galaxy Evolution Explorer (GALEX) under its belly. Release of the Pegasus was scheduled for about 8 a.m. over the Atlantic Ocean at an altitude of 39,000 feet at a location approximately 100 nautical miles offshore east-northeast of Cape Canaveral. Spacecraft separation from the Pegasus occurs 11 minutes later. At that time the satellite will be in a circular orbit of 431 statute miles (690 km) at a 29-degree inclination. The GALEX will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

KSC-03pd1286

NASA Image and Video Library

2003-04-28

KENNEDY SPACE CENTER, FLA. - Orbital Sciences' L-1011 aircraft takes off from Cape Canaveral Air Force Station carrying the Pegasus XL rocket/Galaxy Evolution Explorer (GALEX) under its belly. Release of the Pegasus was scheduled for about 8 a.m. over the Atlantic Ocean at an altitude of 39,000 feet at a location approximately 100 nautical miles offshore east-northeast of Cape Canaveral. Spacecraft separation from the Pegasus occurs 11 minutes later. At that time the satellite will be in a circular orbit of 431 statute miles (690 km) at a 29-degree inclination. The GALEX will carry into space an orbiting telescope that will observe a million galaxies across 10 billion years of cosmic history to help astronomers determine when the stars and elements we see today had their origins. The spacecraft will sweep the skies for 28 months using state-of-the-art ultraviolet detectors to single out galaxies dominated by young, hot, short-lived stars that give off a great deal of energy at that wavelength. These galaxies are actively creating stars, and therefore provide a window into the history and causes of star formation in galaxies.

Investigation of large format microchannel plate Z configurations

NASA Technical Reports Server (NTRS)

Siegmund, O. H. W.; Coburn, K.; Malina, R. F.

1985-01-01

The performance of triplet (Z) stacks of microchannel plates (MCPs) has been studied as a part of the instrument development for the Extreme Ultraviolet Explorer (EUVE) satellite mission. Relatively large MCPs with a 60-mm diameter and having a large 80:1 channel length to diameter (L:D) ratio were used in several configurations. The MCPs were used in the EUVE prototype imaging detector to provide more than 512 x 512 pixels with low image distortion (less than 1 percent). The gain and pulse height characteristics of the MCPs were examined, showing that both high gains (more than 2 x 10 to the 7th) and tight output pulse height distributions (less than 30 percent FWHM) may be achieved. Simple distribution techniques have also allowed low intrinsic background event rates (less than 0.15 events per sq cm/s) to be obtained. Variation of the quantum efficiency of the MCPs over the wavelength range 160-1216 A has been investigated for a range of angles of incidence. The effect of temperature variations on MCP operating characteristics has also been evaluated.

Dynamics Explorer twin spacecraft under evaluation tests

NASA Technical Reports Server (NTRS)

Redmond, C.

1981-01-01

The Dynamics Explorer A and B satellites designed to explore the interactive processes occuring between the magnetosphere and Earth's ionosphere, upper atmosphere, and plasmasphere are described. Effects of these interactions, satellite orbits, data collecting antennas, solar power systems, axes, configurations, and Earth based command, control and data display systems are mentioned.

Global Lunar Gravity Field Recovery from SELENE

NASA Technical Reports Server (NTRS)

Matsumoto, Koji; Heki, Kosuke; Hanada, Hideo

2002-01-01

Results of numerical simulation are presented to examine the global gravity field recovery capability of the Japanese lunar exploration project SELENE (Selenological and Engineering Explorer) which will be launched in 2005. New characteristics of the SELENE lunar gravimetry include four-way satellite-to-satellite Doppler tracking of main orbiter and differential VLBI tracking of two small free-flier satellites. It is shown that planned satellites configuration will improve lunar gravity field in wide range of wavelength as well as far-side selenoid.

Multiple detector focal plane array ultraviolet spectrometer for the AMPS laboratory

NASA Technical Reports Server (NTRS)

Feldman, P. D.

1975-01-01

The possibility of meeting the requirements of the amps spectroscopic instrumentation by using a multi-element focal plane detector array in a conventional spectrograph mount was examined. The requirements of the detector array were determined from the optical design of the spectrometer which in turn depends on the desired level of resolution and sensitivity required. The choice of available detectors and their associated electronics and controls was surveyed, bearing in mind that the data collection rate from this system is so great that on-board processing and reduction of data are absolutely essential. Finally, parallel developments in instrumentation for imaging in astronomy were examined, both in the ultraviolet (for the Large Space Telescope as well as other rocket and satellite programs) and in the visible, to determine what progress in that area can have direct bearing on atmospheric spectroscopy.

ARC-1979-AC79-7104

NASA Image and Video Library

1979-07-07

Range : 1,094,666 km (677,000 mi.) This false color picture of Callisto was taken by Voyager 2 and is centered on 11 degrees N and 171 degrees W. This rendition uses an ultraviolet image for the blue component. Because the surface displays regional contrast in UV, variations in surface materials are apparent. Notice in particular the dark blue haloes which surround bright craters in the eastern hemisphere. The surface of Callisto is the most heavily cratered of the Galilean satellites and resembles ancient heavily cratered terrains on the moon, Mercury and Mars. The bright areas are ejecta thrown out by relatively young impact craters. A large ringed structure, probably an impact basin, is shown in the upper left part of the picture. The color version of this picture was constructed by compositing black and white images taken through the ultraviolet, clear and orange filters.

High-resolution, far-ultraviolet study of Beta Draconis (G2 Ib-II) - Transition region structure and energy balance

NASA Technical Reports Server (NTRS)

Brown, A.; Jordan, C.; Stencel, R. E.; Linsky, J. L.; Ayres, T. R.

1984-01-01

High-resolution far ultraviolet spectra of the star Beta Draconis have been obtained with the IUE satellite. The observations and emission line data from the spectra are presented, the interpretation of the emission line widths and shifts is discussed, and the implications are given in terms of atmospheric properties. The emission measure distribution is derived, and density diagnostics involving both line ratios and line opacity arguments is investigated. The methods for calculating spherically symmetric models of the atmospheric structure are outlined, and several such models are presented. The extension of these models to log T(e) greater than 5.3 using the observed X-ray flux is addressed, the energy balance of an 'optimum' model is investigated, and possible models of energy transport and deposition are discussed.

A search for the cause of cyclical wind variability in O stars. Simultaneous UV and optical observations including magnetic field measurements of the O7.5III star xi Persei

NASA Astrophysics Data System (ADS)

de Jong, J. A.; Henrichs, H. F.; Kaper, L.; Nichols, J. S.; Bjorkman, K.; Bohlender, D. A.; Cao, H.; Gordon, K.; Hill, G.; Jiang, Y.; Kolka, I.; Morrison, N.; Neff, J.; O'Neal, D.; Scheers, B.; Telting, J. H.

2001-03-01

We present the results of an extensive observing campaign on the O7.5 III star xi Persei. The UV observations were obtained with the International Ultraviolet Explorer. xi Per was monitored continuously in October 1994 during 10 days at ultraviolet and visual wavelengths. The ground-based optical observations include magnetic field measurements, Hα and He I lambda 6678 spectra, and were partially covered by photometry and polarimetry. We describe a method to automatically remove the variable contamination of telluric lines in the groundbased spectra. The aim of this campaign was to search for the origin of the cyclical wind variability in this star. We determined a very accurate period of 2.086(2) d in the resonance lines of Si Iv and in the subordinate N Iv and Hα line profiles. The epochs of maximum absorption in the UV resonance lines due to discrete absorption components (DACs) coincide in phase with the maxima in blue-shifted Hα absorption. This implies that the periodic variability originates close to the stellar surface. The phase-velocity relation shows a maximum at -1400 km s-1. The general trend of these observations can be well explained by the corotating interaction region (CIR) model. In this model the wind is perturbed by one or more fixed patches on the stellar surface, which are most probably due to small magnetic field structures. Our magnetic field measurements gave, however, only a null-detection with a 1sigma errorbar of 70 G in the longitudinal component. Some observations are more difficult to fit into this picture. The 2-day period is not detected in the photospheric/transition region line He I lambda 6678. The dynamic spectrum of this line shows a pattern indicating the presence of non-radial pulsation, consistent with the previously reported period of 3.5 h. The edge variability around -2300 km s-1 in the saturated wind lines of C Iv and N V is nearly identical to the edge variability in the unsaturated Si Iv line, supporting the view that this type of variability is also due to the moving DACs. A detailed analysis using Fourier reconstructions reveals that each DAC actually consists of 2 different components: a ``fast'' and a ``slow'' one which merge at higher velocities. Based on observations obtained using the International Ultraviolet Explorer, collected at NASA Goddard Space Flight Center and Villafranca Satellite Tracking Station of the European Space Agency.

Uhuru (SAS-1/Explorer 42)

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

NASA satellite, launched from the San Marco platform off the Kenyan coast in 1970. The first satellite dedicated to x-ray astronomy. Completed an all-sky x-ray survey and studied individual sources. Discovered x-ray binaries, including Hercules X-1 and Centaurus X-1, and confirmed the variability of Cygnus X-1. Uhuru means `freedom' in Swahili. (See also SMALL ASTRONOMY SATELLITE, EXPLORER.)...

Technology Development on ISS for Satellite Servicing and Exploration

NASA Technical Reports Server (NTRS)

Reed, Benjamin B.

2015-01-01

NASA's Satellite Servicing Capabilities Office is utilizing the International Space Station to demonstrate technologies essential to satellite servicing endeavors in support of human exploration and science. Within this presentation, we will discuss the status and implications of three of these technology payloads: Restore-L, Asteroid Redirect Robotic Mission (ARRM), Raven, Robotic Refueling Mission (RRM) Phase 2, and RRM Phase 3.

Daytime O/N2 Retrieval Algorithm for the Ionospheric Connection Explorer (ICON)

NASA Astrophysics Data System (ADS)

Stephan, Andrew W.; Meier, R. R.; England, Scott L.; Mende, Stephen B.; Frey, Harald U.; Immel, Thomas J.

2018-02-01

The NASA Ionospheric Connection Explorer Far-Ultraviolet spectrometer, ICON FUV, will measure altitude profiles of the daytime far-ultraviolet (FUV) OI 135.6 nm and N2 Lyman-Birge-Hopfield (LBH) band emissions that are used to determine thermospheric density profiles and state parameters related to thermospheric composition; specifically the thermospheric column O/N2 ratio (symbolized as ΣO/N2). This paper describes the algorithm concept that has been adapted and updated from one previously applied with success to limb data from the Global Ultraviolet Imager (GUVI) on the NASA Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission. We also describe the requirements that are imposed on the ICON FUV to measure ΣO/N2 over any 500-km sample in daytime with a precision of better than 8.7%. We present results from orbit-simulation testing that demonstrates that the ICON FUV and our thermospheric composition retrieval algorithm can meet these requirements and provide the measurements necessary to address ICON science objectives.

The extreme ultraviolet explorer

NASA Technical Reports Server (NTRS)

Bowyer, Stuart; Malina, Roger F.

1990-01-01

The Extreme Ultraviolet Explorer (EUVE) mission, currently scheduled for launch in September 1991, is described. The primary purpose of the mission is to survey the celestial sphere for astronomical sources of Extreme Ultraviolet (EUV) radiation. The survey will be accomplished with the use of three EUV telescopes, each sensitive to a different segment of the EUV band. A fourth telescope will perform a high sensitivity search of a limited sample of the sky in the shortest wavelength bands. The all sky survey will be carried out in the first six months of the mission and will be made in four bands, or colors. The second phase of the mission, conducted entirely by guest observers selected by NASA, will be devoted to spectroscopic observations of EUV sources. The performance of the instrument components is described. An end to end model of the mission, from a stellar source to the resulting scientific data, was constructed. Hypothetical data from astronomical sources processed through this model are shown.

A multi-wavelength study of the evolution of early-type galaxies in groups: the ultraviolet view

NASA Astrophysics Data System (ADS)

Rampazzo, R.; Mazzei, P.; Marino, A.; Bianchi, L.; Plana, H.; Trinchieri, G.; Uslenghi, M.; Wolter, A.

2018-04-01

The ultraviolet-optical colour magnitude diagram of rich galaxy groups is characterised by a well developed Red Sequence, a Blue Cloud and the so-called Green Valley. Loose, less evolved groups of galaxies which are probably not virialised yet may lack a well defined Red Sequence. This is actually explained in the framework of galaxy evolution. We are focussing on understanding galaxy migration towards the Red Sequence, checking for signatures of such a transition in their photometric and morphological properties. We report on the ultraviolet properties of a sample of early-type (ellipticals+S0s) galaxies inhabiting the Red Sequence. The analysis of their structures, as derived by fitting a Sérsic law to their ultraviolet luminosity profiles, suggests the presence of an underlying disk. This is the hallmark of dissipation processes that still must have a role to play in the evolution of this class of galaxies. Smooth particle hydrodynamic simulations with chemo-photometric implementations able to match the global properties of our targets are used to derive their evolutionary paths through ultraviolet-optical colour magnitude diagrams, providing some fundamental information such as the crossing time through the Green Valley, which depends on their luminosity. The transition from the Blue Cloud to the Red Sequence takes several Gyrs, being about 3-5 Gyr for the brightest galaxies and longer for fainter ones, if occurring. The photometric study of nearby galaxy structures in the ultraviolet is seriously hampered by either the limited field of view of the cameras (e.g., in Hubble Space Telescope) or by the low spatial resolution of the images (e.g., in the Galaxy Evolution Explorer). Current missions equipped with telescopes and cameras sensitive to ultraviolet wavelengths, such as Swift- UVOT and Astrosat-UVIT, provide a relatively large field of view and a better resolution than the Galaxy Evolution Explorer. More powerful ultraviolet instruments (size, resolution and field of view) are obviously bound to yield fundamental advances in the accuracy and depth of the surface photometry and in the characterisation of the galaxy environment.

European Scientific Notes. Volume 37, Number 9.

DTIC Science & Technology

1983-09-30

themes: Reactions of the Ionosphere and Neutral Atmosphere to Magnetospheric Activity, and Pulsations : Correlated Observations from Satellites and the...periods of hundreds of nanosec- heating pulse at 532-nm wavelength was onds. used. Raman data were obtained from J. Bok (l’Ecole Normale Sup4rieuse...both the heating pulse and from a 355-nm France) Bok thce Norato ofpaeser weak ultraviolet probe pulse. The France) viewed the action of laser latter

Determination of Ionospheric Electron Density Profiles from Satellite UV (Ultraviolet) Emission Measurements, Fiscal Year 1984.

DTIC Science & Technology

1985-04-26

distribution function. It is from the calculated distribution function that the photoelectron flux can be derived. The VUV daytime emissions that we are...OECLASSIPICATIONUOOWNdGRADING SCHEDULE Apoe o ulcrlae N/A distribution unlimited .PE RPORMING ORGANIZATION REPORT NUMBER41S( 5. MONITORING ORGANIZATION REPORT...EDP for systems users. This report considers the following ionospheric subregions: (a) the daytime mid- latitude ionosphere from, 90 to 1000 km, (b

The data of establishing a three-dimensional culture system for in vitro recapitulation and mechanism exploration of tumor satellite formation during cancer cell transition.

PubMed

Chen, Chun-Nan; Chen, You-Tzung; Yang, Tsung-Lin

2017-12-01

Tumor satellite formation is an indicator of cancer invasiveness and correlates with recurrence, metastasis, and poorer prognosis. By analyzing pathological specimens, tumor satellites formed at the tumor-host interface reflect the phenomena of epithelial-mesenchymal transition. It is impossible to reveal the dynamic processes and the decisive factors of tumor satellite formation using clinicopathological approaches alone. Therefore, establishment of an in vitro system to monitor the phenomena is important to explicitly elucidate underlying mechanisms. In this study, we explored the feasibility of creating an in vitro three-dimensional collagen culture system to recapitulate the process of tumor satellite formation. This data presented here are referred to the research article (Chen et al., 2017) [1]. Using this model, the dynamic process of tumor satellite formation could be recapitulated in different types of human cancer cells. Induced by calcium deprivation, the treated cells increased the incidence and migratory distance of tumor satellites. E-cadherin internalization and invadopodia formation were enhanced by calcium deprivation and were associated with cellular dynamic change during tumor satellite formation. The data confirmed the utility of this culture system to recapitulate dynamic cellular alteration and to explore the potential mechanisms of tumor satellite formation.