KSC-07pd1645

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians lower the upper canister over the Dawn spacecraft. After enclosure, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1636

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, the Dawn spacecraft has been wrapped with a protective cover before it is enclosed in a canister. Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1646

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians secure the upper canister over the Dawn spacecraft. Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1644

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians begin lowering the upper canister over the Dawn spacecraft. After enclosure, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

Geochemistry at 4 Vesta: Observations Using Fast Neutrons

NASA Technical Reports Server (NTRS)

Lawrence, David J.; Prettyman, Thomas H.; Feldman, William C.; Bazell, David; Mittlefehldt, David W.; Peplowski, Patrick N.; Reedy, Robert C.

2012-01-01

Dawn is currently in orbit around the asteroid 4 Vesta, and one of the major objectives of the mission is to probe the relationship of Vesta to the Howardite, Eucrite, and Diogenite (HED) meteorites. As Vesta is an example of a differentiated planetary embryo, Dawn will also provide fundamental information about planetary evolution in the early solar system [1]. To help accomplish this overall goal, the Dawn spacecraft carries the Gamma-Ray and Neutron Detector (GRaND). GRaND uses planetary gamma-ray and neutron spectroscopy to measure the surface elemental composition of Vesta and will provide information that is unique and complementary to that provided by the other Dawn instruments and investigations. Gamma-ray and neutron spectroscopy is a standard technique for measuring planetary compositions [2], having successfully made measurements at near-Earth asteroids, the Moon, Mars, Mercury and now Vesta. GRaND has made the first measurements of the neutron spectrum from any asteroid (previous asteroid measurements were only made with gamma-rays). Dawn has been collecting data at Vesta since July 2011. The prime data collection period for GRaND is the Low-Altitude Mapping Orbit (LAMO), which started on 12 December 2011 and will last through spring 2012. During LAMO, the Dawn spacecraft orbits at an average altitude of 210 km above the surface of Vesta, which allows good neutron and gamma-ray signals to be detected from Vesta. A description of the overall goals of GRaND and a summary of the initial findings are given elsewhere [3,4]. The subject of this study is to present the information that will be returned from GRaND using fast neutron measurements. Here, we discuss what fast neutrons can reveal about Vesta s surface composition, how such data can address Dawn science goals, and describe fast neutron measurements made in the early portion of the Vesta LAMO phase.

KSC-07pd2429

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is moved toward the opening above the Delta II rocket in the mobile service tower. Dawn will be mated with the Delta in preparation for launch. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2430

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lowered toward the awaiting Delta II rocket in the mobile service tower. Dawn will be mated with the Delta in preparation for launch. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2427

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lifted alongside the mobile service tower. At the top, Dawn will be prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2431

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, workers in the mobile service tower keep watch as the Dawn spacecraft is lowered toward the awaiting Delta II rocket. Dawn will be mated with the Delta in preparation for launch. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2438

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the transportation canister from around the Dawn spacecraft. After removal of the canister, Dawn will be mated with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

KSC-07pd2426

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lifted alongside the mobile service tower. At the top, Dawn will be prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2424

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- The Dawn spacecraft arrives on Launch Pad 17-B at Cape Canaveral Air Force Station. At the pad, Dawn will be lifted into the mobile service tower and prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2442

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, the upper transportation canister is lifted away from the Dawn spacecraft. After removal of the canister, Dawn will be mated with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

KSC-07pd2425

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lifted off its transporter. Dawn will be lifted into the mobile service tower and prepared for mating with the awaiting Delta II rocket.Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd1640

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians move another segment of the lower canister onto the workstand holding the Dawn spacecraft. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1643

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians move the partially enclosed Dawn spacecraft into another room to complete the canning. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1638

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians move the first segment of the lower canister around the upper stage booster below the Dawn spacecraft. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1641

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians place another segment of the canister around the upper stage booster below the Dawn spacecraft. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1642

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians examine the lower canister they placed around the bottom of the Dawn spacecraft. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1637

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians move the first segment of the lower canister toward the stand holding the Dawn spacecraft. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1639

NASA Image and Video Library

2007-06-26

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians move the first segment of the lower canister around the upper stage booster below the Dawn spacecraft. When enclosed in the canister, Dawn will be transported to Launch Pad 17-B and lifted into the mobile service tower for mating with the Delta II launch vehicle. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/George Shelton

KSC-07pd1509

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- The second stage of the Delta II launch vehicle for the Dawn spacecraft arrives on Launch Pad 17-B at Cape Canaveral Air Force Station where it will be mated with the first stage. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

KSC-07pd0864

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- The Dawn spacecraft is seen here in clean room C of Astrotech's Payload Processing Facility. In the clean room, the spacecraft will undergo further processing. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

In-Flight Operation of the Dawn Ion Propulsion System - The First Nine Months

NASA Technical Reports Server (NTRS)

Garner, Charles E.; Brophy, John R.; Mikes, Steven C.; Raymond, Marc D.

2008-01-01

The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) which will provide most of the delta-V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer to Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer to Ceres science orbits. The Dawn ion engine design is based on the design validated on NASA's Deep Space 1 mission. However, because of the very substantial (11 km/s) delta-V requirements for this mission Dawn requires two engines to complete its mission objectives. The power processor units (PPU), digital control and interface units (DCIU) slice boards and the xenon control assembly (XCA) are also based on the DS1 design. The DCIUs and thrust gimbal assemblies (TGA) were developed at the Jet Propulsion Laboratory. The spacecraft was provided by Orbital Sciences Corporation, Sterling, Virginia, and the mission is managed by and operated from the Jet Propulsion Laboratory. Dawn partnered with Germany, Italy and Los Alamos National Laboratory for the science instruments. The mission is led by the principal investigator, Dr. Christopher Russell, from the University of California, Los Angeles. The first 80 days after launch were dedicated to the initial checkout of the spacecraft prior to the initiation of long-term thrusting for the heliocentric transfer to Vesta. The IPS hardware, consisting of three ion thrusters and TGAs, two PPUs and DCIUs, xenon feed system, and spacecraft control software, was investigated extensively. Thrust measurements, roll torque measurements, pointing capabilities, control characteristics, and thermal behavior of the spacecraft and IPS were carefully evaluated. The Dawn IPS fully met all its initial checkout performance objectives. Deterministic thrusting for cruise began on December 17, 2007. Over the subsequent approximately 330 days the IPS will be operated virtually continuously at full power thrusting (approximately 91 mN) leading to a Mars flyby in February 2009. The encounter with Mars provides a gravity assist for a plane change and is the only source of post-launch delta-V apart from the IPS. Following the Mars gravity assist IPS will be operated for approximately one year at full power and for 1.3 years at throttled power levels leading to rendezvous with Vesta in August of 2011. Following nine months of orbital operations with IPS providing the propulsion needed for orbit capture, science orbit transfer and orbit maintenance and Vesta escape, Dawn will transit to Ceres with an expected arrival date of February 2015. As of June 16, 2008 the ion thrusters on Dawn have operated for close to 3,846 hours and have delivered nearly 1 km/s of delta-V to the spacecraft. Dawn IPS operation has been almost flawless during the initial checkout and six months of cruise. This paper provides an overview of Dawn's mission objectives, mission and system design, and the results of the post-launch Dawn IPS mission operations through June 2008

Dawn LAMO Image 19

NASA Image and Video Library

2016-02-03

Tupo Crater on Ceres is seen in this view from NASA Dawn spacecraft. This crater, located in the southern hemisphere of Ceres, was named for the Polynesian god of turmeric. Dawn captured the scene on Dec. 24, 2015.

KSC-07pd0851

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- Two trucks (one air-ride, one flat-bed) deliver the Dawn spacecraft, as well as additional electrical and ground support equipment and xenon ground support equipment, to Astrotech. Dawn will be moved from the truck and the shipping container removed. The spacecraft will then be moved into the high bay of the Payload Processing Facility. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

KSC-07pd2423

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- The Dawn spacecraft is moved out of the Astrotech Space Operations facility, on its way to Launch Pad 17-B at Cape Canaveral Air Force Station. At the pad, Dawn will be lifted into the mobile service tower and prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd2444

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, workers remove the lower segments of the transportation canister away from the Dawn spacecraft. After removal of the canister, Dawn will be mated with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

Dawn LAMO Image 158

NASA Image and Video Library

2016-08-25

An area along the rim of the crater at the center of this view from NASA Dawn spacecraft, has collapsed, producing a lobe-shaped feature where the material settled. The image is centered at approximately 52 degrees north latitude, 316 degrees east longitude. NASA's Dawn spacecraft took this image on May 28, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface of Ceres. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20880

KSC-07pd0852

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech, the shipping container holding the Dawn spacecraft is removed from the truck. The container will then be moved into the high bay of the Payload Processing Facility and the spacecraft removed. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

KSC-07pd0854

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech, the shipping container holding the Dawn spacecraft is moved into the high bay of the Payload Processing Facility. The spacecraft will next be removed from the container. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

Enhanced Ionization Of Propellant Through Carbon Nanotube Growth On Angled Walls

DTIC Science & Technology

2017-06-01

FEEP field emission electric propulsion MUF mass utilization factor NSTAR NASA Solar Technology Application Readiness SCATHA Spacecraft Charging at...Experiments This experiment, Spacecraft Charging at High Altitudes (SCATHA), was developed by the U.S. Air Force along with NASA [5]. A satellite was launched...propulsion system, gimbal mounted and deployed on DS1. Source: [6]. 3. DAWN A more recent use of XIPS is the DAWN Spacecraft from NASA . Orbiting the

KSC-07pd2401

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers move the platform with the Dawn spacecraft. They are preparing to install the transportation canister around Dawn for transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2445

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is ready for mating with the waiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. EDT Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jim Grossmann

KSC-07pd2428

NASA Image and Video Library

2007-09-11

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft arrives at the upper level of the mobile service tower. It will be moved inside and prepared for mating with the awaiting Delta II rocket. Dawn is scheduled for launch in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Photo credit: NASA/Jack Pfaller

KSC-07pd1514

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the second stage of the Delta II launch vehicle for the Dawn spacecraft is lowered into the hole toward the Delta first stage below. The two stages will be mated. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

KSC-07pd1512

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- The second stage of the Delta II launch vehicle for the Dawn spacecraft is lifted alongside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station. It will be mated with the first stage already in the tower. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

KSC-07pd1510

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- The second stage of the Delta II launch vehicle for the Dawn spacecraft is lifted alongside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station. It will be mated with the first stage already in the tower. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

KSC-07pd0853

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech, an external cover is removed from around the shipping container holding the Dawn spacecraft. The container will then be moved into the high bay of the Payload Processing Facility and the spacecraft removed. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

KSC-07pd0862

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- In clean room C of Astrotech's Payload Processing Facility, a worker wearing a "bunny suit," or clean-room attire, begins removing the protective cover surrounding the Dawn spacecraft. In the clean room, the spacecraft will undergo further processing. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

KSC-07pd0863

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- In clean room C of Astrotech's Payload Processing Facility, a worker wearing a "bunny suit," or clean-room attire, looks over the Dawn spacecraft after removing the protective cover, at bottom right. In the clean room, the spacecraft will undergo further processing. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

Dawn HAMO Image 75

NASA Image and Video Library

2015-12-11

This view from NASA Dawn spacecraft shows high northern latitudes on Ceres. Dawn acquired the image on Oct. 17, 2015, from an altitude of 915 miles 1,470 kilometers. It has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20138

Dawn Orbit Determination Team: Trajectory and Gravity Prediction Performance During Vesta Science Phases

NASA Technical Reports Server (NTRS)

Kennedy, Brian; Abrahamson, Matt; Ardito, Alessandro; Han, Dongsuk; Haw, Robert; Mastrodemos, Nicholas; Nandi, Sumita; Park, Ryan; Rush, Brian; Vaughan, Andrew

2013-01-01

The Dawn spacecraft was launched on September 27th, 2007. Its mission is to consecutively rendezvous with and observe the two largest bodies in the asteroid belt, Vesta and Ceres. It has already completed over a year's worth of direct observations of Vesta (spanning from early 2011 through late 2012) and is currently on a cruise trajectory to Ceres, where it will begin scientific observations in mid-2015. Achieving this data collection required careful planning and execution from all spacecraft teams. Dawn's Orbit Determination (OD) team was tasked with accurately predicting the trajectory of the Dawn spacecraft during the Vesta science phases, and also determining the parameters of Vesta to support future science orbit design. The future orbits included the upcoming science phase orbits as well as the transfer orbits between science phases. In all, five science phases were executed at Vesta, and this paper will describe some of the OD team contributions to the planning and execution of those phases.

KSC-07pd1511

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- The second stage of the Delta II launch vehicle for the Dawn spacecraft is lifted alongside the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station. At right can be seen the solid rocket boosters surrounding Delta's first stage. The second stage will be mated with the first stage. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

KSC-07pd1513

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the second stage of the Delta II launch vehicle for the Dawn spacecraft arrives at the upper level of the mobile service tower. It will be moved inside the tower and mated with the first stage already in the tower. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

Dawn: An Ion-Propelled Journey to the Beginning of the Solar System

NASA Technical Reports Server (NTRS)

Brophy, John R.; Rayman, Marc D.; Pavri, Betina

2008-01-01

The Dawn mission is designed to perform a scientific investigation of the two heaviest mainbelt asteroids Vesta and Ceres. These bodies are believed to preserve records of the physical and chemical conditions present during the formation of the solar system. The mission uses an ion propulsion system to enable the single Dawn spacecraft and its complement of scientific instruments to orbit both of these asteroids. Dawn's three science instruments - the gamma ray and neutron detector, the visible and infrared mapping spectrometer, and the primary framing camera - were successfully tested after launch and are functioning normally. The ion propulsion system includes three ion thrusters of the type flown previously on NASA's Deep Space 1 mission. A minimum of two ion thrusters is necessary to accomplish the Dawn mission. Checkout of two of the ion thrusters was completed as planned within 30 days after launch. This activity confirmed that the spacecraft has two healthy ion thrusters. While further checkout activities are still in progress, the activities completed as of the end of October indicate that the spacecraft is well on its way toward being ready for the start of the thrusting-cruise phase of the mission beginning December 15th.

KSC-07pd2405

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers guide the upper transportation canister toward the Dawn spacecraft in the background. The canister will be lowered onto the lower segments and attached. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2407

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers watch as the upper transportation canister is lowered over the Dawn spacecraft. The canister will be attached to the bottom segments already in place. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2403

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers place another segment of the transportation canister around the upper stage booster beneath the Dawn spacecraft. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2404

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers check the fitting on the lower transportation canister segments in place around the upper stage booster beneath the Dawn spacecraft. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2402

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers place the lower segments of the transportation canister around the upper stage booster beneath the Dawn spacecraft. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

KSC-07pd2406

NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers guide the upper transportation canister as it is lowered onto the Dawn spacecraft. The canister will be attached to the bottom segments already in place. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

Ceres From Dawn, Processed

NASA Image and Video Library

2015-01-19

This processed image, taken Jan. 13, 2015, shows the dwarf planet Ceres as seen from the Dawn spacecraft. The image hints at craters on the surface of Ceres. Dawn framing camera took this image at 238,000 miles 383,000 kilometers from Ceres. http://photojournal.jpl.nasa.gov/catalog/PIA19167

Dawn LAMO Image 83

NASA Image and Video Library

2016-05-06

Ceres densely cratered landscape is revealed in this image taken by the framing camera aboard NASA Dawn spacecraft. The craters show various degrees of degradation. The youngest craters have sharp rims.

Dawn LAMO Image 84

NASA Image and Video Library

2016-05-09

Ceres densely cratered landscape is revealed in this image taken by the framing camera aboard NASA Dawn spacecraft. The craters show various degrees of degradation. The youngest craters have sharp rims.

KSC-07pd1243

NASA Image and Video Library

2007-05-21

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers prepare the Dawn spacecraft for thermal blanket installation. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

KSC-07pd1242

NASA Image and Video Library

2007-05-21

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers prepare the Dawn spacecraft for thermal blanket installation. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

KSC-07pd2062

NASA Image and Video Library

2007-07-22

KENNEDY SPACE CENTER, FLA. — Sitting on a transporter, the Dawn spacecraft arrives at the Astrotech payload processing facility. Dawn was returned from Launch Pad 17-B at Cape Canaveral Air Force Station to Astrotech to await a new launch date. The launch opportunity extends from Sept. 7 to Oct. 15. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. NASA/Charisse Nahser

KSC-07pd2063

NASA Image and Video Library

2007-07-22

KENNEDY SPACE CENTER, FLA. — The Dawn spacecraft is moved inside the Astrotech payload processing facility. Dawn was returned from Launch Pad 17-B at Cape Canaveral Air Force Station to Astrotech to await a new launch date. The launch opportunity extends from Sept. 7 to Oct. 15. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. NASA/Charisse Nahser

KSC-07pd1658

NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, workers prepare NASA's Dawn spacecraft mated to the Delta II upper stage booster, for hoisting up into the mobile service tower. Dawn will be mated with the Delta II launch vehicle. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

Ceres During Opposition Surge.

NASA Image and Video Library

2017-05-16

NASA's Dawn spacecraft successfully observed Ceres at opposition on April 29, 2017, taking images from a position exactly between the sun and Ceres' surface. Mission specialists had carefully maneuvered Dawn into a special orbit so that the spacecraft could view Occator Crater, which contains the brightest area of Ceres, from this new perspective. A movie shows these opposition images, with contrast enhanced to highlight brightness differences. The bright spots of Occator stand out particularly well on an otherwise relatively bland surface. Dawn took these images from an altitude of about 12,000 miles (20,000 kilometers). Based on data from ground-based telescopes and spacecraft that have previously viewed planetary bodies at opposition, scientists predicted that Ceres would appear brighter from this opposition configuration. This increase in brightness, or "surge," relates the size of the grains of material on the surface, as well as how porous those materials are. The science motivation for performing these observations is further explained in the March 2017 issue of the Dawn Journal blog. A movie can be viewed at https://photojournal.jpl.nasa.gov/catalog/PIA21405

Dawn LAMO Image 87

NASA Image and Video Library

2016-05-12

This image from NASA Dawn spacecraft shows the rim of Occator crater, just east of the area containing the brightest spots on Ceres. The crater rim has collapsed, leaving structures geologists refer to as terraces.

Dawn HAMO Image 79

NASA Image and Video Library

2015-12-17

NASA Dawn spacecraft captured this scene, showing southern mid-latitudes on Ceres, on Oct. 18, 2015, from an altitude of 915 miles 1,470 kilometers. It has a resolution of 450 feet 140 meters per pixel.

Dawn LAMO Image 73

NASA Image and Video Library

2016-04-22

This image from NASA Dawn spacecraft shows terrain within Chaminuka Crater on Ceres. Chaminuka was named for the spirit who provides rains during times of drought, according to the legends of the Shona people of Zimbabwe.

Dawn LAMO Image 55

NASA Image and Video Library

2016-03-29

This view from NASA Dawn spacecraft shows an area in mid-southern latitudes on Ceres. The crater named Juling 12 miles, 20 kilometers wide is seen at lower right. Bright material is visible along its upper walls.

Dawn LAMO Image 62

NASA Image and Video Library

2016-04-07

Tupo Crater, named for the Polynesian god of turmeric, is shown at upper left in this view of Ceres from NASA Dawn spacecraft. Just below the crater, a line of narrow troughs parallels the rim of Tupo.

KSC-07pd1384

NASA Image and Video Library

2007-06-06

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Hazardous Processing Facility, a technician monitors the loading of xenon for the ion propulsion system in the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Kim Shiflett

KSC-07pd1386

NASA Image and Video Library

2007-06-06

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Hazardous Processing Facility, a technician monitors the loading of xenon for the ion propulsion system in the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Kim Shiflett

KSC-07pd1387

NASA Image and Video Library

2007-06-06

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Hazardous Processing Facility, technicians check data during the loading of xenon for the ion propulsion system in the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Kim Shiflett

KSC-07pd1388

NASA Image and Video Library

2007-06-07

KENNEDY SPACE CENTER, FLA. -- At Astrotech's Hazardous Processing Facility, technicians are loading the Dawn spacecraft with xenon gas for the ion propulsion system. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jim Grossmann

KSC-07pd1385

NASA Image and Video Library

2007-06-06

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Hazardous Processing Facility, technicians check data during the loading of xenon for the ion propulsion system in the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Kim Shiflett

Dawn Gateway View of Ceres

NASA Image and Video Library

2014-12-05

From about three times the distance from Earth to the moon, NASA's Dawn spacecraft spies its final destination -- the dwarf planet Ceres. The resolution of this image does not yet exceed the best views of Ceres, which were obtained by the Hubble Space Telescope (see PIA10235). Nonetheless, Ceres' spherical shape is clearly revealed here. Sunlight illuminates the dwarf planet from the right, leaving a sliver of the surface in shadow at left. A zoomed-in view is provided in Figure 1, along with the original unmagnified, uncropped view. The image was taken on Dec. 1, 2014 with the Dawn spacecraft's framing camera, using a clear spectral filter. Dawn was about 740,000 miles (1.2 million kilometers) from Ceres at the time. Ceres is 590 miles (950 kilometers) across and was discovered in 1801. http://photojournal.jpl.nasa.gov/catalog/PIA19049

Dawn LAMO Image 188

NASA Image and Video Library

2016-10-07

NASA's Dawn spacecraft views Oxo Crater (6 miles, 10 kilometers wide) in this view from Ceres. Dawn took this image on June 4, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20950

KSC-07pd1248

NASA Image and Video Library

2007-05-21

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers begin black light testing on the solar panels of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

KSC-07pd1249

NASA Image and Video Library

2007-05-21

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers begin black light testing on the solar panels of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

Dawn LAMO Image 80

NASA Image and Video Library

2016-05-03

NASA Dawn spacecraft shows Azacca Crater has a prominent set of north-south trending fractures. Its floor is relatively smooth and its rim has terraces descending toward its floor. Azacca was named for the Haitian god of agriculture.

Dawn LAMO Image 25

NASA Image and Video Library

2016-02-11

This image, taken by NASA Dawn spacecraft, shows a densely cratered region within Meanderi Crater on Ceres. Elongated craters in the wall of the largest impact feature are likely the result of material slumping down the crater walls.

Dawn LAMO Image 33

NASA Image and Video Library

2016-02-24

NASA Dawn spacecraft captured this view of a region in the mid-southern latitudes of Ceres. The largest crater in the scene is Fluusa. Fluusa has a densely cratered floor and therefore is interpreted as an old impact feature.

Dawn LAMO Image 32

NASA Image and Video Library

2016-02-23

This image of Ceres from NASA Dawn spacecraft was taken at an oblique viewing angle relative to the surface. The crater to the upper right is named Juling which displays prominent spurs of compacted material along its walls.

Dawn LAMO Image 24

NASA Image and Video Library

2016-02-10

This image, taken by NASA Dawn spacecraft, shows the heavily cratered rim of an older, unnamed impact feature on Ceres. The crater density is almost the same inside and outside, and its wall is also quite battered by impacts.

KSC-07pd1299

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- At Astrotech's Payload Processing Facility, technicians check the Dawn spacecraft as it is lowered onto a transporter. Dawn will be moved to the Hazardous Processing Facility for fueling. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Charisse Nahser

KSC-07pd1305

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- Inside Astrotech's Hazardous Processing Facility, technicians check the Dawn spacecraft as it is lowered onto a scale for weighing. Next, Dawn will be prepared for fueling. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Charisse Nahser

KSC-07pd1300

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. --At Astrotech's Payload Processing Facility, technicians maneuver the shipping container to place around the Dawn spacecraft, at right. Dawn will be moved to the Hazardous Processing Facility for fueling. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Charisse Nahser

KSC-07pd2061

NASA Image and Video Library

2007-07-22

KENNEDY SPACE CENTER, FLA. — On Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is safely secured on a transporter for its trip to Astrotech. Dawn is being returned to the Astrotech payload processing facility to await a new launch date. The launch opportunity extends from Sept. 7 to Oct. 15. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. NASA/George Shelton

KSC-07pd2058

NASA Image and Video Library

2007-07-22

KENNEDY SPACE CENTER, FLA. — On Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lowered from the mobile service tower to the ground. Dawn is being returned to the Astrotech payload processing facility to await a new launch date. The launch opportunity extends from Sept. 7 to Oct. 15. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. NASA/George Shelton

KSC-07pd2059

NASA Image and Video Library

2007-07-22

KENNEDY SPACE CENTER, FLA. — On Pad 17-B at Cape Canaveral Air Force Station, the Dawn spacecraft is lowered from the mobile service tower to the ground. Dawn is being returned to the Astrotech payload processing facility to await a new launch date. The launch opportunity extends from Sept. 7 to Oct. 15. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. NASA/George Shelton

Evidence for the interior evolution of Ceres from geologic analysis of fractures

USGS Publications Warehouse

Scully, Jennifer E. C.; Buczkowski, Debra; Schmedemann, Nico; Raymond, Carol A.; Castillo-Rogez, Julie C.; Scott King,; Bland, Michael T.; Ermakov, Anton; O'Brien, D.P.; Marchi, S.; Longobardo, A.; Russell, C.T.; Fu, R.R.; Neveu, M.

2017-01-01

Ceres is the largest asteroid belt object, and the Dawn spacecraft observed Ceres since 2015. Dawn observed two morphologically distinct linear features on Ceres's surface: secondary crater chains and pit chains. Pit chains provide unique insights into Ceres's interior evolution. We interpret pit chains called the Samhain Catenae as the surface expression of subsurface fractures. Using the pit chains' spacings, we estimate that the localized thickness of Ceres's fractured, outer layer is approximately ≥58 km, at least ~14 km greater than the global average. We hypothesize that extensional stresses, induced by a region of upwelling material arising from convection/diapirism, formed the Samhain Catenae. We derive characteristics for this upwelling material, which can be used as constraints in future interior modeling studies. For example, its predicted location coincides with Hanami Planum, a high-elevation region with a negative residual gravity anomaly, which may be surficial evidence for this proposed region of upwelling material.

Space Weathering on 4 Vesta: Processes and Products

NASA Technical Reports Server (NTRS)

Pieters, C. M.; Blewett, D. T.; Gaffey, M.; Mittlefehldt, D. W.; De Sanctis, M. C.; Reddy, V.; Nathues, A.; Denevi, B. W.; Li, J. Y.; McCord, T. B.;

Dawn HAMO Image 23

NASA Image and Video Library

2015-09-24

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 27, 2015.

Dawn HAMO Image 20

NASA Image and Video Library

2015-09-21

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 26, 2015.

Dawn LAMO Image 106

NASA Image and Video Library

2016-06-09

This image from NASA Dawn spacecraft shows a portion of Ceres known as Erntedank Planum, a broad plateau 345 miles 555 kilometers wide. The terrain seen here lies just to the southeast of Occator Crater, home of Ceres brightest region.

Dawn HAMO Image 82

NASA Image and Video Library

2015-12-22

Part of the southern hemisphere on dwarf planet Ceres is seen in this image taken by NASA Dawn spacecraft. Hamori crater, named after a Japanese god and protector of tree leaves, is the large crater near the center of the image.

Color Map of Ceres Elliptical Projection

NASA Image and Video Library

2016-03-22

This global map elliptical map from NASA Dawn spacecraft shows the surface of Ceres in enhanced color, encompassing infrared wavelengths beyond human visual range. Some areas near the poles are black where Dawn color imaging coverage is incomplete.

Dawn LAMO Image 89

NASA Image and Video Library

2016-05-16

This image captured by NASA Dawn spacecraft features the shadowy rim of an unnamed crater on Ceres. The crater on the left appears relatively old, as its flanks are rugged and the crater density inside it is more or less uniform.

KSC-07pd1389

NASA Image and Video Library

2007-06-07

KENNEDY SPACE CENTER, FLA. -- At Astrotech's Hazardous Processing Facility, technicians look at the connections for loading the Dawn spacecraft with xenon gas for the ion propulsion system. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jim Grossmann

KSC-07pd1390

NASA Image and Video Library

2007-06-07

KENNEDY SPACE CENTER, FLA. -- At Astrotech's Hazardous Processing Facility, a technician checks the connections for loading the Dawn spacecraft with xenon gas for the ion propulsion system. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn spacecraft uses ion propulsion to get the additional velocity needed to reach Vesta once it leaves the Delta rocket. It also uses ion propulsion to spiral to lower altitudes on Vesta, to leave Vesta and cruise to Ceres and to spiral to a low-altitude orbit at Ceres. Ion propulsion makes efficient use of the onboard fuel by accelerating it to a velocity 10 times that of chemical rockets. Dawn is scheduled to launch July 7aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jim Grossmann

KSC-07pd1306

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- Inside Astrotech's Hazardous Processing Facility, the Dawn spacecraft is weighed before fueling. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Charisse Nahser

A Perfect View of Vesta: Creating Pointing Observations for the Dawn Spacecraft on Asteroid 4 Vesta

NASA Technical Reports Server (NTRS)

Hay, Katrina M.

2005-01-01

The Dawn spacecraft has a timely and clever assignment in store. It will take a close look at two intact survivors from the dawn of the solar system (asteroids 4 Vesta and 1 Ceres) to understand more about solar system origin and evolution. To optimize science return, Dawn must make carefully designed observations on approach and in survey orbit, high altitude mapping orbit, and low altitude mapping orbit at each body. In this report, observations outlined in the science plan are modeled using the science opportunity analyzer program for the Vesta encounter. Specifically, I encoded Dawn's flight rules into the program, modeled pointing profiles of the optical instruments (framing camera, visible infrared spectrometer) and mapped their fields of view onto Vesta's surface. Visualization of coverage will provide the science team with information necessary to assess feasibility of alternative observation plans. Dawn launches in summer 2006 and ends its journey in 2016. Instrument observations on Vesta in 2011 will supply detailed information about Vesta's surface and internal structure. These data will be used to analyze the formation and history of the protoplanet and, therefore, complete an important step in understanding the development of our solar system.

Moon Search Algorithms for NASA's Dawn Mission to Asteroid Vesta

NASA Technical Reports Server (NTRS)

Memarsadeghi, Nargess; Mcfadden, Lucy A.; Skillman, David R.; McLean, Brian; Mutchler, Max; Carsenty, Uri; Palmer, Eric E.

2012-01-01

A moon or natural satellite is a celestial body that orbits a planetary body such as a planet, dwarf planet, or an asteroid. Scientists seek understanding the origin and evolution of our solar system by studying moons of these bodies. Additionally, searches for satellites of planetary bodies can be important to protect the safety of a spacecraft as it approaches or orbits a planetary body. If a satellite of a celestial body is found, the mass of that body can also be calculated once its orbit is determined. Ensuring the Dawn spacecraft's safety on its mission to the asteroid Vesta primarily motivated the work of Dawn's Satellite Working Group (SWG) in summer of 2011. Dawn mission scientists and engineers utilized various computational tools and techniques for Vesta's satellite search. The objectives of this paper are to 1) introduce the natural satellite search problem, 2) present the computational challenges, approaches, and tools used when addressing this problem, and 3) describe applications of various image processing and computational algorithms for performing satellite searches to the electronic imaging and computer science community. Furthermore, we hope that this communication would enable Dawn mission scientists to improve their satellite search algorithms and tools and be better prepared for performing the same investigation in 2015, when the spacecraft is scheduled to approach and orbit the dwarf planet Ceres.

KSC-07pd0858

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Payload Processing Facility, an overhead crane lifts the Dawn spacecraft from its transporter. Dawn will be moved into clean room C for unbagging and further processing. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

KSC-07pd1304

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- Inside Astrotech's Hazardous Processing Facility, technicians check the progress of the Dawn spacecraft as it is lifted off the transporter. Dawn will be moved to a scale for weighing and then prepared for fueling. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Charisse Nahser

Searching for organics on the dwarf planet Ceres

NASA Astrophysics Data System (ADS)

Nayak, Michael

The Herschel Space Observatory recently detected the presence of water vapor in observations of Ceres, bringing it into the crosshairs of the search for the building blocks of life in the solar system. I present a mission concept designed in collaboration with the NASA Ames Research Center for a two-probe mission to the dwarf planet Ceres, utilizing a pair of small low-cost spacecraft. The primary spacecraft will carry both a mass and an infrared spectrometer to characterize the detected vapor. Shortly after its arrival a second and largely similar spacecraft will impact Ceres to create an impact ejecta "plume" timed to enable a rendezvous and sampling by the primary spacecraft. This enables additional subsurface chemistry, volatile content and material characterization, and new science complementary to the Dawn spacecraft, the first to arrive at Ceres. Science requirements, candidate instruments, rendezvous trajectories, spacecraft design and comparison with Dawn science are detailed.

KSC-07pd1673

NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, workers supervise the lowering of NASA's Dawn spacecraft in the mobile service tower. The spacecraft is clad in a shipping canister for its transport from Astrotech in Titusville, Fla. The canister will be removed and the spacecraft prepared for launch. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Cory Huston

Comparing Vesta Topography

NASA Image and Video Library

2013-09-27

These two images compare topographic maps of the giant asteroid Vesta as discerned by NASA Hubble Space Telescope top and as seen by NASA Dawn spacecraft bottom. Hubble has been in an orbit around Earth, while Dawn orbited Vesta from 2011 to 2012.

Dawn HAMO Image 34

NASA Image and Video Library

2015-10-09

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on September 15, 2015, and has a resolution of 450 feet 140 meters per pixel.

Dawn HAMO Image 27

NASA Image and Video Library

2015-09-30

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on August 22, 2015, and has a resolution of 450 feet 140 meters per pixel.

Dawn View from OpNav9

NASA Image and Video Library

2015-05-28

This image of Ceres is part of a sequence taken by NASA Dawn spacecraft on May 23, 2015, from a distance of 3,169 miles 5,100 kilometers. Resolution in the image is about 1,565 feet 477 meters per pixel.

Dawn LAMO Image 175

NASA Image and Video Library

2016-09-20

NASA's Dawn spacecraft obtained this view of Laukumate Crater (19 miles, 30 kilometers wide) on Ceres on June 2, 2016. Laukumate is named for a Latvian goddess of agriculture. Dawn took this image from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20937

Dawn LAMO Image 185

NASA Image and Video Library

2016-10-04

NASA's Dawn spacecraft spies Achita Crater on Ceres in this view. Achita is named for a Nigerian god of agriculture and is 25 miles (40 kilometers) wide. Dawn took this image on June 3, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20947

KSC-07pd1227

NASA Image and Video Library

2007-05-16

KENNEDY SPACE CENTER, FLA. -- In Hangar A&O at Cape Canaveral Air Force Station, the Delta II second stage for the Dawn spacecraft is ready for transfer to the launch pad. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/Jack Pfaller

KSC-07pd1265

NASA Image and Video Library

2007-05-23

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers prepare the Dawn spacecraft before test deploying its large solar panels on one side. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KSC-07pd1244

NASA Image and Video Library

2007-05-21

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers prepare to deploy the solar panels of the Dawn spacecraft. The panels will be tested and undergo black light inspection. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

KSC-07pd2066

NASA Image and Video Library

2007-07-22

KENNEDY SPACE CENTER, FLA. — At the Astrotech payload processing facility, workers guide the movement of the upper canister being lifted from the Dawn spacecraft, seen encased in a protective cover. Dawn was returned from Launch Pad 17-B at Cape Canaveral Air Force Station to Astrotech to await a new launch date. The launch opportunity extends from Sept. 7 to Oct. 15. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. NASA/Charisse Nahser

Origin of Dark Material on VESTA from DAWN FC Data: Remnant Carbonaceous Chondrite Impators

NASA Technical Reports Server (NTRS)

Reddy, V.; LeCorre, L.; Nathues, A.; Mittlefehldt, David W.; Cloutis, E. A.; OBrien, D. P.; Durda, D. D.; Bottke, W. F.; Buczkowski, D.; Scully, J. E. C.;

Dawn HAMO Image 42

NASA Image and Video Library

2015-10-21

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres at mid-latitudes, from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 21, 2015, and has a resolution of 450 feet 140 meters per pixel.

Dawn Survey Orbit Image 40

NASA Image and Video Library

2015-08-04

This image, taken by NASA Dawn spacecraft on June 24, 2015, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers with a resolution of 1,400 feet 410 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19613

Dawn LAMO Image 38

NASA Image and Video Library

2016-03-02

NASA Dawn spacecraft obtained this view of Azacca Crater on Ceres. The rim of this crater has terraces descending from its rim down to its floor. The crater floor is relatively free of large impact scars and is named for the Haitian god of agriculture

A Last Look Back at Vesta

NASA Image and Video Library

2012-09-05

This image is from the last sequence of images NASA Dawn spacecraft obtained of the giant asteroid Vesta, looking down at Vesta north pole as it was departing. Dawn escaped from Vesta orbit on Sept. 4, 2012 PDT Sept. 5, 2012 CET.

Dawn LAMO Image 90

NASA Image and Video Library

2016-05-17

This image from NASA Dawn spacecraft shows the western rim of Azacca Crater on Ceres. A smaller impact feature sits on its flank. Of particular interest in this scene is the great number of small, bright spots, in the southern part of the image.

Dawn HAMO Image 40

NASA Image and Video Library

2015-10-19

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 20, 2015, and has a resolution of 450 feet 140 meters per pixel.

Dawn HAMO Image 41

NASA Image and Video Library

2015-10-20

This image, taken by NASA Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 21, 2015, and has a resolution of 450 feet 140 meters per pixel.

KSC-07pd1674

NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, workers supervise the movement of NASA's Dawn spacecraft in the mobile service tower. The spacecraft is clad in a shipping canister for its transport from Astrotech in Titusville, Fla. The canister will be removed and the spacecraft will be mated with the Delta II launch vehicle in the tower. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Cory Huston

KSC-07pd1256

NASA Image and Video Library

2007-05-22

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, the Dawn spacecraft is lowered toward a work stand for solar panel installation. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KSC-07pd1260

NASA Image and Video Library

2007-05-22

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers prepare the Dawn spacecraft for installation of its solar array panels. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KSC-07pd0856

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Payload Processing Facility, a crane lifts the shipping container from the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

KSC-07pd1264

NASA Image and Video Library

2007-05-23

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers get ready to test deploy the large solar array panels on one side of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KSC-07pd1246

NASA Image and Video Library

2007-05-21

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, the solar panels of the Dawn spacecraft are extended to their full extent. The panels will be tested and undergo black light inspection. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

Solar maximum mission fine pointing sun sensor dawn and dusk errors flight data and model analysis

NASA Technical Reports Server (NTRS)

Kulp, D. R.

1988-01-01

SMM flight system control errors occurring at spacecraft dawn and dusk are analyzed. The errors are associated with the fine pointing sun sensor (FPSS), which is a primary component of the SMM attitude control system. It is shown that the source of the FPSS dawn/dusk distortion is the incomplete masking of sunlight reflected off the earth by the optical baffle covering the FPSS sensor heads onboard the SMM during periods of orbit dawn and dusk. For the most part, the modeled behavior of the FPSS under dawn and dusk lighting conditions matches the observed behavior in the SMM flight data.

Dawn Survey Orbit Image 32

NASA Image and Video Library

2015-07-22

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 25, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19601

Dawn Survey Orbit Image 23

NASA Image and Video Library

2015-07-09

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 22, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19591

Dawn HAMO Image 16

NASA Image and Video Library

2015-09-15

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19894

Dawn Survey Orbit Image 5

NASA Image and Video Library

2015-06-16

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 6, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19573

Dawn HAMO Image 19

NASA Image and Video Library

2015-09-18

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 26, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19897

Dawn Survey Orbit Image 31

NASA Image and Video Library

2015-07-21

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 25, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19600

Dawn OpNav9 Image 5

NASA Image and Video Library

2015-06-12

This image of Ceres is part of a sequence taken by NASA Dawn spacecraft on May 22, 2015, from a distance of 3,200 miles 5,100 kilometers with a resolution of 1,600 feet 480 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19567

Dawn Survey Orbit Image 26

NASA Image and Video Library

2015-07-14

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19594

Dawn Survey Orbit Image 15

NASA Image and Video Library

2015-06-26

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 10, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19583

Dawn Survey Orbit Image 4

NASA Image and Video Library

2015-06-15

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 6, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19572

Dawn OpNav9 Image 4

NASA Image and Video Library

2015-06-11

This image of Ceres is part of a sequence taken by NASA Dawn spacecraft on May 22, 2015, from a distance of 3,200 miles 5,100 kilometers with a resolution of 1,600 feet 480 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19566

Dawn OpNav9 Image 3

NASA Image and Video Library

2015-06-10

This image of Ceres is part of a sequence taken by NASA Dawn spacecraft on May 22, 2015, from a distance of 3,200 miles 5,100 kilometers with a resolution of 1,600 feet 480 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19565

Dawn HAMO Image 17

NASA Image and Video Library

2015-09-16

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 25, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19895

Dawn Survey Orbit Image 8

NASA Image and Video Library

2015-06-19

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 6, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19576

Dawn HAMO Image 15

NASA Image and Video Library

2015-09-14

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19893

Dawn OpNav9 Image 1

NASA Image and Video Library

2015-06-08

This image of Ceres is part of a sequence taken by NASA Dawn spacecraft on May 22, 2015, from a distance of 3,200 miles 5,100 kilometers with a resolution of 1,600 feet 480 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19563

Dawn HAMO Image 21

NASA Image and Video Library

2015-09-22

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 27, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19899

Dawn HAMO Image 14

NASA Image and Video Library

2015-09-11

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19892

Dawn Survey Orbit Image 22

NASA Image and Video Library

2015-07-08

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 18, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19590

Dawn HAMO Image 18

NASA Image and Video Library

2015-09-17

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 26, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19896

Dawn Survey Orbit Image 30

NASA Image and Video Library

2015-07-20

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19599

Dawn Survey Orbit Image 28

NASA Image and Video Library

2015-07-16

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 25, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19596

Dawn Survey Orbit Image 12

NASA Image and Video Library

2015-06-23

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 7, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19580

Dawn OpNav9 Image 2

NASA Image and Video Library

2015-06-09

This image of Ceres is part of a sequence taken by NASA Dawn spacecraft on May 22, 2015, from a distance of 3,200 miles 5,100 kilometers with a resolution of 1,600 feet 480 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19564

Dawn Survey Orbit Image 27

NASA Image and Video Library

2015-07-15

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19595

Dawn HAMO Image 22

NASA Image and Video Library

2015-09-23

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 27, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19900

Dawn Survey Orbit Image 7

NASA Image and Video Library

2015-06-18

This image, taken by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 9, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19575

Dawn First Glimpse of Vesta -- Processed

NASA Image and Video Library

2011-05-11

This image, processed to show the true size of the giant asteroid Vesta, shows Vesta in front of a spectacular background of stars. It was obtained by the framing camera aboard NASA Dawn spacecraft on May 3, 2011, from a distance of about 750,000 miles.

KSC-07pd1515

NASA Image and Video Library

2007-06-15

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, workers maneuver the second stage of the Delta II launch vehicle onto the first stage for mating. The Delta II-Heavy, manufactured by the United Launch Alliance, is scheduled to launch the Dawn spacecraft on its 4-year flight to the asteroid belt. The Delta II-Heavy is the strongest rocket in the Delta II class. It will use three stages and nine solid-fueled booster rockets to propel Dawn on its way. A 9.5-foot payload fairing will protect the spacecraft from the heat and stresses of launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Dawn is scheduled to launch July 7. Photo credit: NASA/Jack Pfaller

In-Flight Operation of the Dawn Ion Propulsion System Through Start of the Vesta Cruise Phase

NASA Technical Reports Server (NTRS)

Garner, Charles E.; Rayman, Marc D.; Brophy, John R.

2009-01-01

The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) which will provide most of the delta V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer to Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer to Ceres science orbits. The Dawn ion design is based on the design validated on NASA's Deep Space 1 (DS1) mission. However, because of the very substantial (11 km/s) delta V requirements for this mission Dawn requires two engines to complete its mission objectives. The power processor units (PPU), digital control and interface units (DCIU) slice boards and the xenon control assembly (XCA) are derivatives of the components used on DS1. The DCIUs and thrust gimbal assemblies (TGA) were developed at the Jet Propulsion Laboratory. The spacecraft was provided by Orbital Sciences Corporation, Sterling, Virginia, and the mission is managed by and operated from the Jet Propulsion Laboratory. Dawn partnered with Germany, Italy and Los Alamos National Laboratory for the science instruments. The mission is led by the principal investigator, Dr. Christopher Russell, from the University of California, Los Angeles. The first 80 days after launch were dedicated to the initial checkout of the spacecraft followed by cruise to Mars. Cruise thrusting leading to a Mars gravity assist began on December 17, 2007 and was successfully concluded as planned on October 31, 2008. During this time period the Dawn IPS was operated mostly at full power for approximately 6500 hours, consumed 71.7 kg of xenon and delivered approximately 1.8 km/s of delta V to the spacecraft. The thrusting to Mars was followed by a coasting period of approximately 3.5 months that included a Mars flyby in February of 2009. The Mars flyby provided a gravity assist (MGA) for a plane change and approximately 1 km/s of heliocentric energy increase and is the only part of the mission following launch in which a needed velocity change is not accomplished by the IPS. During the coast period IPS was operated for a trajectory correction maneuver and for engineering tests but was not operated for primary propulsion. Closest approach to Mars occurred as planned on February 17, 2009 and was followed by another coasting period of just under 4 months in duration. During this last coasting phase IPS was operated only for routine maintenance activities and for system engineering tests. Deterministic thrusting for heliocentric transfer to Vesta resumed on June 8, 2009. IPS will be operated for over two years at throttled power levels leading to arrival at Vesta in September of 2011 and arrival at Ceres in February 2015. This paper provides an overview of Dawn's mission objectives and the results of Dawn IPS mission operations through the start of deterministic thrusting to Vesta.

KSC-07pd0860

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Payload Processing Facility, technicians roll the Dawn spacecraft into clean room C for unbagging and further processing. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

KSC-07pd1257

NASA Image and Video Library

2007-05-22

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, the Dawn spacecraft, secure on a work stand, is moved to another room for solar panel installation. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KSC-07pd0857

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Payload Processing Facility, a crane is being attached to the Dawn spacecraft to lift it from the transporter. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

KSC-07pd0855

NASA Image and Video Library

2007-04-10

KENNEDY SPACE CENTER, FLA. -- In Astrotech's Payload Processing Facility, a crane is attached to the shipping container to remove it from around the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/Jim Grossmann

KSC-07pd1254

NASA Image and Video Library

2007-05-22

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers prepare the Dawn spacecraft to be moved to a work stand for solar panel installation. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KSC-07pd1266

NASA Image and Video Library

2007-05-23

KENNEDY SPACE CENTER, FLA. -- At Astrotech, the more than 32-foot-long solar panels on one side of the Dawn spacecraft glide open during a test deployment. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KSC-07pd1279

NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- At Astrotech, a suspended set of solar array panels is opened prior to installation on the Dawn spacecraft. Another set was installed previously. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/George Shelton

KSC-07pd1255

NASA Image and Video Library

2007-05-22

KENNEDY SPACE CENTER, FLA. -- In a clean room at Astrotech, workers stand near while the Dawn spacecraft is lifted and moved toward a work stand for solar panel installation. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

KSC-07pd1268

NASA Image and Video Library

2007-05-23

KENNEDY SPACE CENTER, FLA. -- At Astrotech, the more than 32-foot-long solar panels on one side of the Dawn spacecraft are fully deployed during a test. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KSC-07pd1269

NASA Image and Video Library

2007-05-23

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers check the Dawn spacecraft after testing the deployment of its more than 32-foot-long solar panels on one side. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KSC-07pd1263

NASA Image and Video Library

2007-05-23

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers fold the large solar array panels on one side of the Dawn spacecraft. The panels will be tested for deployment and stowage. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/George Shelton

KSC-07pd1259

NASA Image and Video Library

2007-05-22

KENNEDY SPACE CENTER, FLA. -- In another clean room at Astrotech, solar array panels at left are ready to be installed on the Dawn spacecraft, at right. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Photo credit: NASA/Jack Pfaller

Dawn HAMO Image 32

NASA Image and Video Library

2015-10-07

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on September 9, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19910

Dawn HAMO Image 31

NASA Image and Video Library

2015-10-06

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on September 9, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19909

Dawn HAMO Image 33

NASA Image and Video Library

2015-10-08

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on September 14, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19971

Dawn HAMO Image 30

NASA Image and Video Library

2015-10-05

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on September 9, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19908

Dawn HAMO Image 36

NASA Image and Video Library

2015-10-13

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on September 20, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19978

Dawn HAMO Image 37

NASA Image and Video Library

2015-10-14

This image, taken by NASA Dawn spacecraft on Sept. 20, 2015, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19979

Dawn HAMO Image 35

NASA Image and Video Library

2015-10-12

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on August 23, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19972

Dawn HAMO Image 29

NASA Image and Video Library

2015-10-02

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on September 9, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19907

Dawn HAMO Image 9

NASA Image and Video Library

2015-09-03

This image, taken by NASA Dawn spacecraft, shows a portion of Ceres at mid-latitudes from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19885

Dawn HAMO Image 28

NASA Image and Video Library

2015-10-01

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on August 24, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19906

Dawn HAMO Image 25

NASA Image and Video Library

2015-09-28

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on August 21, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19903

Dawn HAMO Image 26

NASA Image and Video Library

2015-09-29

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on August 21, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19904

Dawn HAMO Image 24

NASA Image and Video Library

2015-09-25

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on August 21, 2015, and has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19902

Densely Cratered Terrain Near the Terminator

NASA Image and Video Library

2011-08-16

NASA Dawn spacecraft shows densely cratered terrain near Vesta terminator on August 6, 2011. This image was taken through the framing camera clear filter aboard the spacecraft. North is pointing towards the two oclock position.

Dawn HAMO Image 44

NASA Image and Video Library

2015-10-23

This image, taken by NASA Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 21, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19986

Dawn HAMO Image 10

NASA Image and Video Library

2015-09-04

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19886

Dawn Survey Orbit Image 53

NASA Image and Video Library

2015-08-24

This image, taken by NASA's Dawn spacecraft, shows the bright spots of Occator crater on Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 25, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19630

Dawn HAMO Image 52

NASA Image and Video Library

2015-11-04

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres at mid-latitudes from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 29, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19994

Dawn HAMO Image 8

NASA Image and Video Library

2015-09-02

This image, taken by NASA Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19884

Dawn HAMO Image 12

NASA Image and Video Library

2015-09-10

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19888

Dawn HAMO Image 48

NASA Image and Video Library

2015-10-29

This image, taken by NASA Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 22, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19990

Dawn Survey Orbit Image 34

NASA Image and Video Library

2015-07-24

This image, taken on June 25, 2015 by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers, with a resolution of 1,400 feet 410 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19603

Dawn HAMO Image 6

NASA Image and Video Library

2015-08-31

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19882

Dawn HAMO Image 7

NASA Image and Video Library

2015-09-01

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19883

Dawn HAMO Image 45

NASA Image and Video Library

2015-10-26

This image, taken by NASA Dawn spacecraft, shows the surface of dwarf planet Ceres at mid-latitudes from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 21, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19987

Dawn HAMO Image 5

NASA Image and Video Library

2015-08-28

This image, taken by NASA Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19881

Dawn HAMO Image 4

NASA Image and Video Library

2015-08-27

This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image, with a resolution of 450 feet (140 meters) per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19635

Dawn HAMO Image 43

NASA Image and Video Library

2015-10-22

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 21, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19985

Dawn Survey Orbit Image 35

NASA Image and Video Library

2015-07-27

This image, taken by NASA Dawn spacecraft, shows the brightest spots on dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers. The image, with a resolution of 1,400 feet 410 meters per pixel, was taken on June 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19604

Dawn HAMO Image 38

NASA Image and Video Library

2015-10-15

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 20, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19980

Dawn Survey Orbit Image 13

NASA Image and Video Library

2015-06-24

The north pole of Ceres can be seen in this image taken on June 9, 2015 by NASA Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers with a resolution of 1,400 feet 410 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19581

Dawn HAMO Image 11

NASA Image and Video Library

2015-09-08

This image, taken by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image, with a resolution of 450 feet 140 meters per pixel, was taken on August 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19887

Dawn HAMO Image 49

NASA Image and Video Library

2015-10-30

This image, taken by NASA Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles 1,470 kilometers. The image was taken on Sept. 22, 2015, and has a resolution of 450 feet 140 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19991

Dawn Survey Orbit Image 33

NASA Image and Video Library

2015-07-23

This image, taken on June 25, 2015 by NASA Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles 4,400 kilometers, with a resolution of 1,400 feet 410 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19602

Dawn Survey Orbit Image 45

NASA Image and Video Library

2015-08-11

This image, taken June 6, 2015 by NASA Dawn spacecraft, shows Haulani crater on Ceres from an altitude of 2,700 miles 4,400 kilometers with a resolution of 1,400 feet 410 meters per pixel. North on Ceres is toward upper right. http://photojournal.jpl.nasa.gov/catalog/PIA19621

KSC-07pd0865

NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- In clean room C of Astrotech's Payload Processing Facility, technicians dressed in "bunny suits," or clean-room attire, begin working on the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

KSC-07pd1307

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- The mobile service towers on Launch Pads 17-A (left) and 17-B (right) are silhouetted against the pre-dawn sky at Cape Canaveral Air Force Station. In the background are the launch gantries. Pad 17-B is the site for the launch of the Dawn spacecraft on June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Amanda Diller

KSC-07pd1212

NASA Image and Video Library

2007-05-16

KENNEDY SPACE CENTER, FLA. -- In Hangar M on Cape Canaveral Air Force Station, the first stage of the Delta II rocket that will launch the Dawn spacecraft is ready to be transferred to a transporter for its move to the launch pad. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/Jack Pfaller

Dawn LAMO Image 182

NASA Image and Video Library

2016-09-29

NASA's Dawn spacecraft views Kupalo Crater in this view of Ceres. Kupalo, which measures 16 miles (26 kilometers) across and is located at southern mid-latitudes, is named for the Slavic god of vegetation and harvest. Dawn took this image on June 2, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20944

Dawn LAMO Image 5

NASA Image and Video Library

2016-01-13

This view of the Cerean crater Victa was captured by NASA Dawn spacecraft on Dec. 19, 2015. The steep-walled crater is approximately 19 miles 30 kilometers in diameter, and was named for the Roman goddess of food and nourishment. Dawn took this image from its low-altitude mapping orbit (LAMO), at an approximate altitude of 240 miles (385 kilometers) above Ceres. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20195

In-Flight Operation of the Dawn Ion Propulsion System: Status at One Year from the Vesta Rendezvous

NASA Technical Reports Server (NTRS)

Garner, Charles E.; Rayman, Marc D.

2010-01-01

The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218 kg spacecraft into an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) developed at the Jet Propulsion Laboratory which will provide most of the delta V needed for heliocentric transfer to Vesta, orbit capture at Vesta, transfer among Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer among Ceres science orbits. The Dawn ion thruster [I thought we only called it a thruster. Both terms are used in the paper, but I think a replacement of every occurrence of "engine" with "thruster" would be clearer.] design is based on the design validated on NASA's Deep Space 1 (DS1) mission. However, because of the very substantial (11 km/s) delta V requirements for this mission Dawn requires two engines to complete its mission objectives. The power processor units (PPU), digital control and interface units (DCIU) slice boards and the xenon control assembly (XCA) are derivatives of the components used on DS1. The DCIUs and thrust gimbal assemblies (TGA) were developed at the Jet Propulsion Laboratory. The spacecraft was provided by Orbital Sciences Corporation, Sterling, Virginia, and the mission is managed by and operated from the Jet Propulsion Laboratory. Dawn partnered with Germany, Italy and Los Alamos National Laboratory for the science instruments. The mission is led by the principal investigator, Dr. Christopher Russell, from the University of California, Los Angeles. The first 80 days after launch were dedicated to the initial checkout of the spacecraft followed by cruise to Mars. Cruise thrusting leading to a Mars gravity assist began on December 17, 2007 and was successfully concluded as planned on October 31, 2008. During this time period the Dawn IPS was operated mostly at full power for approximately 6500 hours, consumed 71.7 kg of xenon and delivered approximately 1.8 km/s of delta V to the spacecraft. The thrusting to Mars was followed by a coasting period of approximately 3.5 months that included a Mars flyby in February of 2009. The Mars flyby provided a gravity assist (MGA) for a plane change and approximately 1 km/s of heliocentric energy increase and is the only part of the mission following launch in which a needed velocity change is not accomplished by the IPS. During the coast period IPS was operated for a trajectory correction maneuver and for engineering tests but was not operated for primary propulsion. Closest approach to Mars occurred as planned on February 17, 2009 and was followed by another coasting period of just under 4 months in duration. During this last coasting phase IPS was operated only for routine maintenance activities and for system engineering tests. Deterministic thrusting for heliocentric transfer to Vesta resumed on June 8, 2009. Since resumption of cruise to Vesta IPS has been operated at throttled power levels, most of the time at full power, and with a duty cycle of approximately 93%, leading to an arrival at Vesta in July of 2011 and arrival at Ceres in February 2015. This paper provides an overview of Dawn's mission objectives and the results of Dawn IPS mission operations through one year from the spacecraft's rendezvous with Vesta.

First results from the ionospheric radio occultations of Saturn by the Cassini spacecraft

NASA Astrophysics Data System (ADS)

Nagy, Andrew F.; Kliore, Arvydas J.; Marouf, Essam; French, Richard; Flasar, Michael; Rappaport, Nicole J.; Anabtawi, Aseel; Asmar, Sami W.; Johnston, Douglas; Barbinis, Elias; Goltz, Gene; Fleischman, Don

2006-06-01

The first set of near-equatorial occultations of the Saturn ionosphere was obtained by the Cassini spacecraft between May and September of 2005. The occultations occurred at near-equatorial latitudes, between 10°N and 10°S, at solar zenith angles from about 84° to 96°. The entry observations correspond to dusk conditions and the exit ones to dawn. An initial look at the data indicates that the average peak densities are lower and the peak altitude higher at dawn than at dusk, possibly the result of ionospheric decay during the night hours. There are also significant differences between individual dawn and dusk occultations; the initial thought is that this variation must be connected to changes in the water inflow into the upper atmosphere and/or variations in the particle impact ionization rates.

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NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers ensure the upper transportation canister is securely attached to the lower segments. The canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

Navigation Image of Ceres

NASA Image and Video Library

2017-04-07

NASA's Dawn spacecraft took this picture on its way to a new orbit, at an altitude of about 30,000 miles (48,300 kilometers), as part of a series of images intended to help the navigation of the spacecraft relative to Ceres. The image was taken on March 28, 2017. Several familiar features can be identified: At the top, we see Occator Crater and its faculae (bright deposits identified as a mixture of sodium carbonate and other salts). Below center is the crater Urvara, and to the right of it, the larger crater Yalode (the third and second largest craters on Ceres, respectively). Large-scale faults called Samhain Catenae stretch from the Occator region toward the Yalode-Urvara region. The spacecraft will settle into a new orbit that will allow it to observe Ceres in opposition at the end of April 2017, when Dawn is directly between the sun and the Occator bright spots, at an altitude of about 12,400 miles (20,000 kilometers). The Dawn Journal has more details about the science expected from these observations. https://photojournal.jpl.nasa.gov/catalog/PIA21401

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NASA Image and Video Library

2007-09-27

KENNEDY SPACE CENTER, FLA. -- Rising above a cloud-filled horizon, the Delta II rocket carrying the Dawn spacecraft roars into the sky. Liftoff was at 7:34 a.m. EDT from Pad 17-B at Cape Canaveral Air Force Station. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Kim Shiflett

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- NASA's Dawn spacecraft moves out of the Astrotech facility in Titusville, Fla., for transportation to Launch Pad 17-B at Cape Canaveral Air Force Station, and mate to the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-09-27

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket with the Dawn spacecraft on top waits in the early morning light for launch. Liftoff was at 7:34 a.m. EDT from Pad 17-B at Cape Canaveral Air Force Station. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Kim Shiflett

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NASA Image and Video Library

2007-09-27

KENNEDY SPACE CENTER, FLA. -- Rising into billowing clouds above the horizon, the Delta II rocket carrying the Dawn spacecraft roars into the sky. Liftoff was at 7:34 a.m. EDT from Pad 17-B at Cape Canaveral Air Force Station. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/George Shelton

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At the top of Launch Pad 17-B, at Cape Canaveral Air Force Station, workers help to guide NASA’s Dawn spacecraft into position for stacking with the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-09-27

KENNEDY SPACE CENTER, FLA. -- Leaving the clouds behind, the Delta II rocket carrying the Dawn spacecraft arcs through the blue sky over the Atlantic Ocean. Liftoff was at 7:34 a.m. EDT from Pad 17-B at Cape Canaveral Air Force Station. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/George Shelton

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, workers position NASA's Dawn spacecraft to mate it with the Delta II launch vehicle below. Launch is scheduled for July 7. Dawn is the ninth mission in NASA’s Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, NASA's Dawn spacecraft is hoisted up on the pad in preparation for stacking with the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, workers position NASA’s Dawn spacecraft to lower it toward the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At the top of Launch Pad 17-B, at Cape Canaveral Air Force Station, workers help to guide NASA’s Dawn spacecraft into position for stacking with the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

Dawn HAMO Image 67

NASA Image and Video Library

2015-12-01

The tall, cone-shaped mountain Ahuna Mons is seen in this image taken by NASA's Dawn spacecraft. Ahuna Mons, named for the traditional post-harvest festival of the Sumi tribe of Nagaland in India, is about 4 miles (6 kilometers) tall and 12 miles (20 kilometers) in diameter. Dawn took this image on Oct. 14, 2015, from an altitude of 915 miles (1,470 kilometers). It has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20130

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NASA Image and Video Library

2007-04-11

KENNEDY SPACE CENTER, FLA. -- In clean room C of Astrotech's Payload Processing Facility, a worker wears a "bunny suit," or clean-room attire, next to the Dawn spacecraft, which will be unbagged and undergo further processing. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. The Dawn mission is managed by JPL, a division of the California Institute of Technology in Pasadena, for NASA's Science Mission Directorate in Washington, D.C. Photo credit: NASA/George Shelton

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NASA Image and Video Library

2007-05-24

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers prepare the Dawn spacecraft, at left, for installation of a second set of solar array panels, at right. Together, the panels extend 64.6 feet when fully open. Dawn is scheduled to launch June 30 aboard a Delta II rocket from Launch Complex 17-B at Cape Canaveral Air Force Station. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/George Shelton

Dawn Survey Orbit Image 20

NASA Image and Video Library

2015-07-06

This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 22, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19588

Dawn Survey Orbit Image 29

NASA Image and Video Library

2015-07-17

This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 25, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19597

Dawn Survey Orbit Image 17

NASA Image and Video Library

2015-06-30

This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 16, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19585

Dawn Survey Orbit Image 25

NASA Image and Video Library

2015-07-13

This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19593

Dawn Survey Orbit Image 24

NASA Image and Video Library

2015-07-10

This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 21, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19592

Dawn Survey Orbit Image 46

NASA Image and Video Library

2015-08-12

This image, taken on June 6, 2015 by NASA Dawn spacecraft, shows a mountain on Ceres at center-left that is 4 miles 6 kilometers high, from an altitude of 2,700 miles 4,400 kilometers with a resolution of 1,400 feet 410 meters per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19622

DAWN Mission Bus and Waveguide Venting Analysis Review

NASA Technical Reports Server (NTRS)

Cragg, Clinton H.; Kichak, Robert A.; Sutter, James K.; Holder, Donald; Jeng, Frank; Ruitberg, Arthur; Sank, Victor

2007-01-01

A concern was raised regarding the time after launch when the DAWN Mission Communications Subsystem, which contains a 100 Watt X-Band Traveling Wave Tube Amplifier (TWTA) with a high voltage ((approximately 7 Kilo Volt (KV)) Electronic Power Converter (EPC), will be powered on for the first post-launch downlink. This activation is planned to be approximately one hour after launch. Orbital Sciences (the DAWN Mission spacecraft contractor) typically requires a 24-hour wait period prior to high voltage initiation for Earth-orbiting Science and GEO spacecraft. The concern relates to the issue of corona and/or radio frequency (RF) breakdown of the TWTA ((high voltage direct current (DC) and RF)), and of the microwave components (high voltage RF) in the presence of partial atmospheric pressures or outgassing constituents. In particular, generally the diplexer and circulator are susceptible to RF breakdown in the corona region due to the presence of small physical gaps (( 2.5 millimeter (mm)) between conductors that carry an RF voltage. The NESC concurred the DAWN Mission communication system is safe for activation.

Thrust Direction Optimization: Satisfying Dawn's Attitude Agility Constraints

NASA Technical Reports Server (NTRS)

Whiffen, Gregory J.

2013-01-01

The science objective of NASA's Dawn Discovery mission is to explore the two largest members of the main asteroid belt, the giant asteroid Vesta and the dwarf planet Ceres. Dawn successfully completed its orbital mission at Vesta. The Dawn spacecraft has complex, difficult to quantify, and in some cases severe limitations on its attitude agility. The low-thrust transfers between science orbits at Vesta required very complex time varying thrust directions due to the strong and complex gravity and various science objectives. Traditional thrust design objectives (like minimum (Delta)V or minimum transfer time) often result in thrust direction time evolutions that can not be accommodated with the attitude control system available on Dawn. This paper presents several new optimal control objectives, collectively called thrust direction optimization that were developed and necessary to successfully navigate Dawn through all orbital transfers at Vesta.

Modeling to Improve the Risk Reduction Process for Command File Errors

NASA Technical Reports Server (NTRS)

Meshkat, Leila; Bryant, Larry; Waggoner, Bruce

2013-01-01

The Jet Propulsion Laboratory has learned that even innocuous errors in the spacecraft command process can have significantly detrimental effects on a space mission. Consequently, such Command File Errors (CFE), regardless of their effect on the spacecraft, are treated as significant events for which a root cause is identified and corrected. A CFE during space mission operations is often the symptom of imbalance or inadequacy within the system that encompasses the hardware and software used for command generation as well as the human experts and processes involved in this endeavor. As we move into an era of increased collaboration with other NASA centers and commercial partners, these systems become more and more complex. Consequently, the ability to thoroughly model and analyze CFEs formally in order to reduce the risk they pose is increasingly important. In this paper, we summarize the results of applying modeling techniques previously developed to the DAWN flight project. The original models were built with the input of subject matter experts from several flight projects. We have now customized these models to address specific questions for the DAWN flight project and formulating use cases to address their unique mission needs. The goal of this effort is to enhance the project's ability to meet commanding reliability requirements for operations and to assist them in managing their Command File Errors.

Vesta Surface Comes into View

NASA Image and Video Library

2011-06-13

This image from the framing camera aboard NASA Dawn spacecraft shows surface details beginning to resolve as the spacecraft closes in on the giant asteroid Vesta on June 1, 2011, from a distance of about 300,000 miles 483,000 kilometers.

Preparing for Dawn's Mission at Ceres: Challenges and Opportunities in the Exploration of a Dwarf Planet

NASA Technical Reports Server (NTRS)

Rayman, Marc D.; Mase, Robert A.

2014-01-01

After escaping from Vesta in 2012, Dawn is continuing its 2.5-year flight to dwarf planet Ceres. Investigating this second destination promises to provide a view of an intriguing world of ice and rock, likely displaying fascinating geology entirely unlike any body yet orbited by a spacecraft. Dawn spends the significant majority of the time thrusting with its ion propulsion system to deliver the 3.6 km/s required to rendezvous with Ceres. Meanwhile, the operations team has developed the sequences that will be used there. Following orbit capture in March 2015, Dawn will fly to a series of four circular polar science orbits. The orbits, ranging from about 13,500 km to 375 km in altitude, are designed to optimize the scientific observations. The overall strategy for exploring Ceres is based strongly on the extremely successful 16 months of Vesta operations, during which Dawn met or exceeded all of its objectives. Nevertheless, the loss of two of the spacecraft's four reaction wheels has necessitated some important changes. Based on a very productive hydrazine conservation campaign in the interplanetary cruise and the development of new hydrazine-efficient methods of operating at Ceres, there is good reason to expect that Dawn will be able to accomplish all of its objectives regardless of the health of the reaction wheels. This paper describes the progress in traveling to Ceres as well as the plans for exploring this giant, icy world.

Dawn Survey Orbit Image 38

NASA Image and Video Library

2015-07-31

This image, taken by NASA's Dawn spacecraft, shows cratered terrain near the day-night line, called the terminator, on dwarf planet Ceres. The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken at an altitude of 2,700 miles (4,400 kilometers) on June 24, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19611

Dawn Survey Orbit Image 21

NASA Image and Video Library

2015-07-07

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 17, 2015. A bright area called "Spot 1" can be seen in this image. http://photojournal.jpl.nasa.gov/catalog/PIA19589

Dawn Survey Orbit Image 14

NASA Image and Video Library

2015-06-25

This image, taken by NASA's Dawn spacecraft, shows dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 9, 2015. The bright feature in the upper-left is also seen in PIA19581. http://photojournal.jpl.nasa.gov/catalog/PIA19582

Thrust Direction Optimization: Satisfying Dawn's Attitude Agility Constraints

NASA Technical Reports Server (NTRS)

Whiffen, Gregory J.

2013-01-01

The science objective of NASA's Dawn Discovery mission is to explore the giant asteroid Vesta and the dwarf planet Ceres, the two largest members of the main asteroid belt. Dawn successfully completed its orbital mission at Vesta. The Dawn spacecraft has complex, difficult to quantify, and in some cases severe limitations on its attitude agility. The low-thrust transfers between science orbits at Vesta required very complex time varying thrust directions due to the strong and complex gravity and various science objectives. Traditional low-thrust design objectives (like minimum change in velocity or minimum transfer time) often result in thrust direction time evolutions that cannot be accommodated with the attitude control system available on Dawn. This paper presents several new optimal control objectives, collectively called thrust direction optimization that were developed and turned out to be essential to the successful navigation of Dawn at Vesta.

KSC-07pd1664

NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, the Delta II launch vehicle with NASA’s Dawn spacecraft mission logo can be seen as it is moved into position for stacking with the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA’s first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, workers attach a crane to NASA's Dawn spacecraft. It will be lifted into the mobile service tower for mating to the Delta II launch vehicle.Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

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NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- NASA's Dawn spacecraft, mated to the Delta II upper stage booster, arrives at Launch Pad 17-B at Cape Canaveral Air Force Station. It will be lifted into the mobile service tower for mating to the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

KSC-07pd1653

NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- Inside the Astrotech Facility in Titusville, Fla., NASA’s Dawn spacecraft is ready to be transported to Launch Pad 17-B at Cape Canaveral Air Force Station, for mate to the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

KSC-07pd1657

NASA Image and Video Library

2007-06-27

KENNEDY SPACE CENTER, FLA. -- At Launch Pad 17-B, at Cape Canaveral Air Force Station, workers attach a crane to NASA's Dawn spacecraft mated to the Delta II upper stage booster, in preparation for stacking with the Delta II launch vehicle. Launch is scheduled for July 7. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Troy Cryder.

KSC-07pd1721

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, workers complete encapsulation of the fairing around NASA's Dawn spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

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NASA Image and Video Library

2007-09-10

KENNEDY SPACE CENTER, FLA. -- At Astrotech Space Operations in Titusville, Fla., workers ensure the upper transportation canister is securely attached to the lower segments. The transportation canister will protect the spacecraft and booster during transfer to Launch Pad 17-B at Cape Canaveral Air Force Station (CCAFS). During its nearly decade-long mission, the Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission, the Dawn spacecraft will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field and thus bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch via a Delta II rocket is scheduled in a window from 7:25 to 7:54 a.m. Sept. 26 from CCAFS. Photo credit: NASA/Jim Grossmann

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NASA Image and Video Library

2007-05-17

KENNEDY SPACE CENTER, FLA. -- In the Astrotech Space Operations facility, Orbital Science technicians install a computer chip on the Dawn spacecraft. The silicon chip holds the names of more than 360,000 space enthusiasts worldwide who signed up to participate in a virtual voyage to the asteroid belt and is about the size of an American five-cent coin. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/Jim Grossmann

Dawn XMO2 Image 29

NASA Image and Video Library

2017-01-11

Ikapati Crater on Ceres is seen at top right in this image from NASA's Dawn spacecraft. Ikapati has a complex of central peaks and roughly parallel fractures on its floor. The crater, named for a Philippine goddess of cultivated lands, measures 31 miles (50 kilometers) in diameter. Dawn took this image on Oct. 24, 2016, during its second extended-mission science orbit (XMO2), from a distance of about 920 miles (1,480 kilometers) above the surface of Ceres. The image resolution is about 460 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21249

KSC-07pd1238

NASA Image and Video Library

2007-05-17

KENNEDY SPACE CENTER, FLA. -- In the Astrotech Space Operations facility, a computer chip awaits installation on the Dawn spacecraft. The silicon chip holds the names of more than 360,000 space enthusiasts worldwide who signed up to participate in a virtual voyage to the asteroid belt and is about the size of an American five-cent coin. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/Jim Grossmann

Chemical Mixing Model and K-Th-Ti Systematics and HED Meteorites for the Dawn Mission

NASA Technical Reports Server (NTRS)

Usui, T.; McSween, H. Y., Jr.; Mittlefehldt, D. W.; Prettyman, T. H.

2009-01-01

The Dawn mission will explore 4 Vesta, a large differentiated asteroid believed to be the parent body of the howardite, eucrite and diogenite (HED) meteorite suite. The Dawn spacecraft carries a gamma-ray and neutron detector (GRaND), which will measure the abundances of selected elements on the surface of Vesta. This study provides ways to leverage the large geochemical database on HED meteorites as a tool for interpreting chemical analyses by GRaND of mapped units on the surface of Vesta.

KSC-07pd2400

NASA Image and Video Library

2007-09-01

KENNEDY SPACE CENTER, FLA. -- This logo represents the mission of the Dawn spacecraft. During its nearly decade-long mission, Dawn will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. The mission hopes to unlock some of the mysteries of planetary formation, including the building blocks and the processes leading to their state today. The Dawn mission is managed by the Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., for NASA's Science Mission Directorate in Washington, D.C.

Use of Cumulative Degradation Factor Prediction and Life Test Result of the Thruster Gimbal Assembly Actuator for the Dawn Flight Project

NASA Technical Reports Server (NTRS)

Lo, C. John; Brophy, John R.; Etters, M. Andy; Ramesham, Rajeshuni; Jones, William R., Jr.; Jansen, Mark J.

2009-01-01

The Dawn Ion Propulsion System is the ninth project in NASA s Discovery Program. The Dawn spacecraft is being developed to enable the scientific investigation of the two heaviest main-belt asteroids, Vesta and Ceres. Dawn is the first mission to orbit two extraterrestrial bodies, and the first to orbit a main-belt asteroid. The mission is enabled by the onboard Ion Propulsion System (IPS) to provide the post-launch delta-V. The three Ion Engines of the IPS are mounted on Thruster Gimbal Assembly (TGA), with only one engine operating at a time for this 10-year mission. The three TGAs weigh 14.6 kg.

30-kW SEP Spacecraft as Secondary Payloads for Low-Cost Deep Space Science Missions

NASA Technical Reports Server (NTRS)

Brophy, John R.; Larson, Tim

2013-01-01

The Solar Array System contracts awarded by NASA's Space Technology Mission Directorate are developing solar arrays in the 30 kW to 50 kW power range (beginning of life at 1 AU) that have significantly higher specific powers (W/kg) and much smaller stowed volumes than conventional rigid-panel arrays. The successful development of these solar array technologies has the potential to enable new types of solar electric propulsion (SEP) vehicles and missions. This paper describes a 30-kW electric propulsion vehicle built into an EELV Secondary Payload Adapter (ESPA) ring. The system uses an ESPA ring as the primary structure and packages two 15-kW Megaflex solar array wings, two 14-kW Hall thrusters, a hydrazine Reaction Control Subsystem (RCS), 220 kg of xenon, 26 kg of hydrazine, and an avionics module that contains all of the rest of the spacecraft bus functions and the instrument suite. Direct-drive is used to maximize the propulsion subsystem efficiency and minimize the resulting waste heat and required radiator area. This is critical for packaging a high-power spacecraft into a very small volume. The fully-margined system dry mass would be approximately 1120 kg. This is not a small dry mass for a Discovery-class spacecraft, for example, the Dawn spacecraft dry mass was only about 750 kg. But the Dawn electric propulsion subsystem could process a maximum input power of 2.5 kW, and this spacecraft would process 28 kW, an increase of more than a factor of ten. With direct-drive the specific impulse would be limited to about 2,000 s assuming a nominal solar array output voltage of 300 V. The resulting spacecraft would have a beginning of life acceleration that is more than an order of magnitude greater than the Dawn spacecraft. Since the spacecraft would be built into an ESPA ring it could be launched as a secondary payload to a geosynchronous transfer orbit significantly reducing the launch costs for a planetary spacecraft. The SEP system would perform the escape from Earth and then the heliocentric transfer to the science target.

The Enabling Use of Ion Propulsion on Dawn

NASA Astrophysics Data System (ADS)

Rayman, M.; Russell, C. T.; Raymond, C. A.; Mase, R. M.

2011-12-01

Dawn's mission to orbit both Vesta and Ceres is enabled by its use of ion propulsion. Even orbiting Vesta alone with conventional propulsion would have been unaffordable within the constraints of the Discovery Program, and orbiting both would have been impossible. In fact, no other spacecraft has been targeted to orbit two solar system destinations, which is only one of the many firsts that Dawn will achieve. The successful testing of ion propulsion on Deep Space 1 paved the way for Dawn not only to use the hardware with confidence but also to learn how to design the flight system and design the mission to take advantage of its capabilities. In addition to allowing Dawn to reach these two important targets, ion propulsion allows the spacecraft to accomplish significant changes in its orbit. Therefore, science observations of Vesta are planned from four different orbits, at varying altitudes and solar geometry. The use of ion propulsion results in a significant mission design effort since the trajectory is constantly being refined. This also creates a flexible mission architecture, which allows for optimization of the mission as conditions change. Solar electric ion propulsion is especially well suited to missions to the Main Asteroid Belt since solar energy is still a viable power source, whereas the size of the solar array needed beyond 3.5 AU is a potential limitation. Dawn has already surpassed the record for greatest propulsive velocity, but its greatest achievements will no doubt be the incredible bounty of science data enabled by this innovative flight system.

KSC-07pd1714

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the first half of the fairing is lifted into the mobile service tower for encapsulation around NASA's Dawn spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1715

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, workers prepare the first half of the fairing for encapsulation around NASA's Dawn spacecraft. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1716

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, a worker oversees the movement of the first half of the fairing toward NASA's Dawn spacecraft for encapsulation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1720

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the second half of the fairing moves toward NASA's Dawn spacecraft to complete encapsulation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1718

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, workers supervise the movement of the first half of the fairing toward NASA's Dawn spacecraft for encapsulation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1713

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- NASA's Dawn spacecraft waits for fairing encapsulation in the mobile service tower of Launch Pad 17-B at Cape Canaveral Air Force Station in Florida. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1717

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, the first half of the fairing moves toward NASA's Dawn spacecraft for encapsulation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

KSC-07pd1719

NASA Image and Video Library

2007-07-01

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station in Florida, workers supervise the movement of the first half of the fairing toward NASA's Dawn spacecraft for encapsulation. The fairing is a molded structure that fits flush with the outside surface of the Delta II upper stage booster and forms an aerodynamically smooth nose cone, protecting the spacecraft during launch and ascent. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is scheduled for July 8. Photo credit: NASA/Amanda Diller

Dawn LAMO Image 134

NASA Image and Video Library

2016-07-22

Liber Crater is featured at lower left in this image from Ceres. Named for the Roman god of agriculture, Liber is 14 miles 23 kilometers. NASA's Dawn spacecraft took this image on June 16, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20834

KSC-07pd1321

NASA Image and Video Library

2007-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the 1st stage of the Delta II rocket awaits solid rocket booster attachment. The rocket is the launch vehicle for the Dawn spacecraft, scheduled to launch June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Jim Grossmann

KSC-07pd1241

NASA Image and Video Library

2007-05-17

KENNEDY SPACE CENTER, FLA. -- In the Astrotech Space Operations facility, Orbital Science technicians verify that a computer chip is securely bonded to a side brace on the Dawn spacecraft. The silicon chip holds the names of more than 360,000 space enthusiasts worldwide who signed up to participate in a virtual voyage to the asteroid belt and is about the size of an American five-cent coin. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/George Shelton

Dawn XMO2 Image 3

NASA Image and Video Library

2016-11-09

Relatively young craters, with sharp crater rims and streaks of bright material, are the focus of this view of Ceres from NASA's Dawn spacecraft. The large, ancient and quite degraded crater Fluusa is seen at top center. The younger craters are Kupalo, at lower right, and Juling, to its left. Dawn took this image on Oct. 17, 2016, from its second extended-mission science orbit (XMO2), at a distance of about 920 miles (1,480 kilometers) above the surface. The image resolution is about 460 feet (140 meters) per pxel. http://photojournal.jpl.nasa.gov/catalog/PIA21223

KSC-07pd1240

NASA Image and Video Library

2007-05-17

KENNEDY SPACE CENTER, FLA. -- In the Astrotech Space Operations facility, a computer chip is bonded to a side brace on the Dawn spacecraft. The silicon chip holds the names of more than 360,000 space enthusiasts worldwide who signed up to participate in a virtual voyage to the asteroid belt and is about the size of an American five-cent coin. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Dawn is scheduled to launch June 30 from Launch Complex 17-B. Photo credit: NASA/Jim Grossmann

Dawn Orbit Determination Team: Trajectory Modeling and Reconstruction Processes at Vesta

NASA Technical Reports Server (NTRS)

Abrahamson, Matthew J.; Ardito, Alessandro; Han, Dongsuk; Haw, Robert; Kennedy, Brian; Mastrodemos, Nick; Nandi, Sumita; Park, Ryan; Rush, Brian; Vaughan, Andrew

2013-01-01

The Dawn spacecraft spent over a year in orbit around Vesta from July 2011 through August 2012. In order to maintain the designated science reference orbits and enable the transfers between those orbits, precise and timely orbit determination was required. Challenges included low-thrust ion propulsion modeling, estimation of relatively unknown Vesta gravity and rotation models, track-ing data limitations, incorporation of real-time telemetry into dynamics model updates, and rapid maneuver design cycles during transfers. This paper discusses the dynamics models, filter configuration, and data processing implemented to deliver a rapid orbit determination capability to the Dawn project.

A hydromagnetic vortex seen by ISEE-1 and 2

NASA Technical Reports Server (NTRS)

Saunders, M. A.; Southwood, D. J.; Hones, E. W., Jr.; Russell, C. T.

1981-01-01

Magnetometer and plasma data from the dual ISEE spacecraft are combined in a study of the initial plasma vortex event reported by Hones et al. (1978) in the dawn plasma sheet. The event is a transient hydromagnetic wave of two cycles duration with a six minute period. Large amplitude compressional and transverse magnetic components were present. Particle and magnetic pressure oscillations were in strict antiphase, but did not balance. When combined with the plasma velocity data these properties show that substantial Earthward field-aligned flows of electromagnetic energy and heat flux occurred during the vortex. The net energy flow perpendicular to B was in the antisolar direction. This event possesses hydromagnetic features unique to a hot plasma environment.

Enhanced Early View of Ceres from Dawn

NASA Image and Video Library

2014-12-05

As the Dawn spacecraft flies through space toward the dwarf planet Ceres, the unexplored world appears to its camera as a bright light in the distance, full of possibility for scientific discovery. This view was acquired as part of a final calibration of the science camera before Dawn's arrival at Ceres. To accomplish this, the camera needed to take pictures of a target that appears just a few pixels across. On Dec. 1, 2014, Ceres was about nine pixels in diameter, nearly perfect for this calibration. The images provide data on very subtle optical properties of the camera that scientists will use when they analyze and interpret the details of some of the pictures returned from orbit. Ceres is the bright spot in the center of the image. Because the dwarf planet is much brighter than the stars in the background, the camera team selected a long exposure time to make the stars visible. The long exposure made Ceres appear overexposed, and exaggerated its size; this was corrected by superimposing a shorter exposure of the dwarf planet in the center of the image. A cropped, magnified view of Ceres appears in the inset image at lower left. The image was taken on Dec. 1, 2014 with the Dawn spacecraft's framing camera, using a clear spectral filter. Dawn was about 740,000 miles (1.2 million kilometers) from Ceres at the time. Ceres is 590 miles (950 kilometers) across and was discovered in 1801. http://photojournal.jpl.nasa.gov/catalog/PIA19050

Comparing Vesta's Surface Roughness to the Moon Using Bistatic Radar Observations by the Dawn Mission

NASA Astrophysics Data System (ADS)

Palmer, E. M.; Heggy, E.; Kofman, W. W.; Moghaddam, M.

2015-12-01

The first orbital bistatic radar (BSR) observations of a small body have been conducted opportunistically by NASA's Dawn spacecraft at Asteroid Vesta using the telecommunications antenna aboard Dawn to transmit and the Deep Space Network 70-meter antennas on Earth to receive. Dawn's high-gain communications antenna continuously transmitted right-hand circularly polarized radio waves (4-cm wavelength), and due to the opportunistic nature of the experiment, remained in a fixed orientation pointed toward Earth throughout each BSR observation. As a consequence, Dawn's transmitted radio waves scattered from Vesta's surface just before and after each occultation of the Dawn spacecraft behind Vesta, resulting in surface echoes at highly oblique incidence angles of greater than 85 degrees, and a small Doppler shift of ~2 Hz between the carrier signal and surface echoes from Vesta. We analyze the power and Doppler spreading of Vesta's surface echoes to assess surface roughness, and find that Vesta's area-normalized radar cross section ranges from -8 to -17 dB, which is notably much stronger than backscatter radar cross section values reported for the Moon's limbs (-20 to -35 dB). However, our measurements correspond to the forward scattering regime--such that at high incidence, radar waves are expected to scatter more weakly from a rough surface in the backscatter direction than that which is scattered forward. Using scattering models of rough surfaces observed at high incidence, we report on the relative roughness of Vesta's surface as compared to the Moon and icy Galilean satellites. Through this, we assess the dominant processes that have influenced Vesta's surface roughness at centimeter and decimeter scales, which are in turn applicable to assisting future landing, sampling and orbital missions of other small bodies.

In-Flight Operation of the Dawn Ion Propulsion System Through Survey Science Orbit at Ceres

NASA Technical Reports Server (NTRS)

Garner, Charles E.; Rayman, Marc D.

2015-01-01

The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration of the two most massive main-belt objects, Vesta and Ceres. The Dawn spacecraft was launched from the Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H- 9.5 (Delta-II Heavy) rocket that placed the 1218-kg spacecraft onto an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) developed at the Jet Propulsion Laboratory which will provide a total delta V of 11 km/s for the heliocentric transfer to Vesta, orbit capture at Vesta, transfer between Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer between Ceres science orbits. Full-power thrusting from December 2007 through October 2008 was used to successfully target a Mars gravity assist flyby in February 2009 that provided an additional delta V of 2.6 km/s. Deterministic thrusting for the heliocentric transfer to Vesta resumed in June 2009 and concluded with orbit capture at Vesta on July 16, 2011. From July 2011 through September 2012 the IPS was used to transfer to all the different science orbits at Vesta and to escape from Vesta orbit. Cruise for a rendezvous with Ceres began in September 2012 and concluded with the start of the approach to Ceres phase on December 26, 2015, leading to orbit capture on March 6, 2015. Deterministic thrusting continued during approach to place the spacecraft in its first science orbit, called RC3, which was achieved on April 23, 2015. Following science operations at RC3 ion thrusting was resumed for twenty-five days leading to arrival to the next science orbit, called survey orbit, on June 3, 2015. The IPS will be used for all subsequent orbit transfers and trajectory correction maneuvers until completion of the primary mission in approximately June 2016. To date the IPS has been operated for over 46,774 hours, consumed approximately 393 kg of xenon, and provided a delta V of over 10.8 km/s to the spacecraft. The IPS performance characteristics are very close to the expected performance based on analysis and testing performed pre-launch. This paper provides an overview of Dawn's mission objectives and the results of Dawn IPS mission operations through arrival at the second science orbit at Ceres.

Dawn LAMO Image 136

NASA Image and Video Library

2016-07-26

Liber Crater is featured at lower left in this image from Ceres. Named for the Roman god of agriculture, Liber is 14 miles (23 kilometers) wide. NASA's Dawn spacecraft took this image on June 16, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20834

FT-IR and µ-IR characterization of HED meteorites in relation to infrared spectra of Vesta-like asteroids

NASA Astrophysics Data System (ADS)

Ferrari, M.; Dirri, F.; Palomba, E.; Stefani, S.; Longobardo, A.; Rotundi, A.

2017-09-01

We present the results of the FT-IR and µ-IR study of three Howardite-Eucrite-Diogenite meteorites (HEDs) compared to the spectroscopic data collected by VIR onboard Dawn spacecraft. The origin of this group of achondrites is thought to be linked to the asteroid 4 Vesta, hypothesis lately reinforced by the data provided by the Dawn mission.

KSC-07pd1308

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- The first stage of a Delta II rocket rolls under the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station. The rocket is the launch vehicle for the Dawn spacecraft, targeted for liftoff on June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Amanda Diller

KSC-07pd1313

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the first stage of a Delta II rocket is placed in the mobile service tower. The rocket is the launch vehicle for the Dawn spacecraft, targeted for liftoff on June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Amanda Diller

KSC-07pd1327

NASA Image and Video Library

2007-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, one of nine solid rocket boosters is lifted into the mobile service tower. It will be attached to the Delta II first stage for the launch of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Jim Grossmann

KSC-07pd1329

NASA Image and Video Library

2007-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, a second solid rocket booster is ready to be lifted into the mobile service tower. It will be attached to the Delta II first stage for the launch of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Jim Grossmann

KSC-07pd1323

NASA Image and Video Library

2007-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, workers prepare the solid rocket booster to be raised off the transporter. The SRB is one of nine to be mated to the Delta II rocket that will launch the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Jim Grossmann

Earth - Moon Conjunction

NASA Technical Reports Server (NTRS)

1992-01-01

On December 16, 1992, 8 days after its encounter with Earth, the Galileo spacecraft looked back from a distance of about 6.2 million kilometers (3.9 million miles) to capture this remarkable view of the Moon in orbit about Earth. The composite photograph was constructed from images taken through visible (violet, red) and near-infrared (1.0-micron) filters. The Moon is in the foreground; its orbital path is from left to right. Brightly colored Earth contrasts strongly with the Moon, which reacts only about one-third as much sunlight as our world. To improve the visibility of both bodies, contrast and color have been computer enhanced. At the bottom of Earth's disk, Antarctica is visible through clouds. The Moon's far side can also be seen. The shadowy indentation in the Moon's dawn terminator--the boundary between its dark and lit sides--is the South Pole-Aitken Basin, one of the largest and oldest lunar impact features. This feature was studied extensively by Galileo during the first Earth flyby in December 1990.

Dawn at Vesta: testing the protoplanetary paradigm

USGS Publications Warehouse

Russell, C.T.; Raymond, C.A.; Coradini, A.; McSween, H.Y.; Zuber, M.T.; Nathues, A.; DeSanctis, Maria-Cristina; Jaumann, R.; Konopliv, A.S.; Preusker, F.; Asmar, S.W.; Park, R.S.; Gaskell, R.; Keller, H.U.; Mottola, S.; Roatsch, T.; Scully, J.E.C.; Smith, D.E.; Tricarico, P.; Toplis, M.J.; Christensen, U.R.; Feldman, W.C.; Lawrence, D.J.; McCoy, T.J.; Prettyman, T.H.; Reedy, R.C.; Sykes, M.E.; Titus, T.N.

2012-01-01

The Dawn spacecraft targeted 4 Vesta, believed to be a remnant intact protoplanet from the earliest epoch of solar system formation, based on analyses of howardite-eucrite-diogenite (HED) meteorites that indicate a differentiated parent body. Dawn observations reveal a giant basin at Vesta's south pole, whose excavation was sufficient to produce Vesta-family asteroids (Vestoids) and HED meteorites. The spatially resolved mineralogy of the surface reflects the composition of the HED meteorites, confirming the formation of Vesta's crust by melting of a chondritic parent body. Vesta's mass, volume, and gravitational field are consistent with a core having an average radius of 107 to 113 kilometers, indicating sufficient internal melting to segregate iron. Dawn's results confirm predictions that Vesta differentiated and support its identification as the parent body of the HEDs.

Using DOUBLE STAR and CLUSTER Synoptic Observations to Test Global MHD Simulations of the Large-scale Topology of the Dayside Merging Region

NASA Astrophysics Data System (ADS)

Berchem, J.; Marchaudon, A.; Bosqued, J.; Escoubet, C. P.; Dunlop, M.; Owen, C. J.; Reme, H.; Balogh, A.; Carr, C.; Fazakerley, A. N.; Cao, J. B.

2005-12-01

Synoptic measurements from the DOUBLE STAR and CLUSTER spacecraft offer a unique opportunity to evaluate global models in simulating the complex topology and dynamics of the dayside merging region. We compare observations from the DOUBLE STAR TC-1 and CLUSTER spacecraft on May 8, 2004 with the predictions from a three-dimensional magnetohydrodynamic (MHD) simulation that uses plasma and magnetic field parameters measured upstream of the bow shock by the WIND spacecraft. Results from the global simulation are consistent with the large-scale features observed by CLUSTER and TC-1. We discuss topological changes and plasma flows at the dayside magnetospheric boundary inferred from the simulation results. The simulation shows that the DOUBLE STAR spacecraft passed through the dawn side merging region as the IMF rotated. In particular, the simulation indicates that at times TC-1 was very close to the merging region. In addition, we found that the bifurcation of the merging region in the simulation results is consistent with predictions by the antiparallel merging model. However, because of the draping of the magnetosheath field lines over the magnetopause, the positions and shape of the merging region differ significantly from those predicted by the model.

KSC-07pd2592

NASA Image and Video Library

2007-09-27

KENNEDY SPACE CENTER, FLA. -- Nearly enveloped by the smoke after ignition, the Delta II rocket carrying NASA's Dawn spacecraft rises from the smoke and fire on the launch pad to begin its 1.7-billion-mile journey through the inner solar system to study a pair of asteroids. Liftoff was at 7:34 a.m. EDT from Pad 17-B at Cape Canaveral Air Force Station. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Sandra Joseph & Rafael Hernandez

Dawn XMO2 Image 28

NASA Image and Video Library

2017-01-03

Meanderi Crater on Ceres is seen at lower right in this image from NASA's Dawn spacecraft. Meanderi -- named for the Ngaing goddess (New Guinea) of taro, sugar cane and other foods -- hosts several medium-sized craters within its walls. Meanderi measures 64 miles (103 kilometers) in diameter. The crater is centered at 41 degrees south, 194 degrees east. Dawn took this image on Oct. 26, 2016, during its second extended-mission science orbit (XMO2), from a distance of about 920 miles (1,480 kilometers) above the surface of Ceres. The image resolution is about 460 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21248

Revealing Shadows 1

NASA Image and Video Library

2012-07-23

These images from NASA Dawn spacecraft, located in Vesta Caparronia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

Dawn Survey Orbit Image 36

NASA Image and Video Library

2015-07-29

This image, taken by NASA's Dawn spacecraft, shows Dantu crater on dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 24, 2015. Dantu, at bottom center, is about 75 miles (120 kilometers) across and 3 miles (5 kilometers) deep, has small patches of bright material sprinkled around it. http://photojournal.jpl.nasa.gov/catalog/PIA19609

Views of Ceres on Approach

NASA Image and Video Library

2015-02-25

These images of dwarf planet Ceres, processed to enhance clarity, were taken on Feb. 19, 2015, from a distance of about 29,000 miles 46,000 kilometers, by NASA Dawn spacecraft. Dawn observed Ceres completing one full rotation, lasting about nine hours. The images show the full range of different crater shapes that can be found at Ceres' surface: from shallow, flattish craters to those with peaks at their centers. http://photojournal.jpl.nasa.gov/catalog/PIA19183

Dawn HAMO Image 47

NASA Image and Video Library

2015-10-28

This image, taken by NASA's Dawn spacecraft, shows a portion of the northern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on Sept. 22, 2015, and has a resolution of 450 feet (140 meters) per pixel. Jarovit crater, named for the Slavic god of fertility and harvest, is seen at lower left. Its diameter is 41 miles (66 kilometers). http://photojournal.jpl.nasa.gov/catalog/PIA19989

Dawn HAMO Image 50

NASA Image and Video Library

2015-11-02

This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers). The image was taken on Sept. 28, 2015, and has a resolution of 450 feet (140 meters) per pixel. Urvara crater, named for the Indian and Iranian deity of plants and fields, is featured. Its diameter is 101 miles (163 kilometers). http://photojournal.jpl.nasa.gov/catalog/PIA19992

Revealing Shadows 6

NASA Image and Video Library

2012-07-30

These images from NASA Dawn spacecraft, located in asteroid Vesta Caparronia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

Revealing Shadows 3

NASA Image and Video Library

2012-07-25

These images from NASA Dawn spacecraft, located in asteroid Vesta Marcia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

Revealing Shadows 2

NASA Image and Video Library

2012-07-24

These images from NASA Dawn spacecraft, located in asteroid Vesta Oppia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

Revealing Shadows 7

NASA Image and Video Library

2012-07-31

These images from NASA Dawn spacecraft, located in asteroid VestaFloronia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

Revealing Shadows 5

NASA Image and Video Library

2012-07-27

These images from NASA Dawn spacecraft, located in asteroid Vesta Floronia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

Revealing Shadows 4

NASA Image and Video Library

2012-07-26

These images from NASA Dawn spacecraft, located in asteroid Vesta Marcia quadrangle, in Vesta northern hemisphere, demonstrate a special analytical technique, which results in shadowed areas of Vesta surface becoming illuminated.

KSC-07pd2578

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket is revealed as the mobile service tower, or gantry (at right), is retracted on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2582

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- Rollback of the mobile service tower, or gantry, from the Delta II rocket is complete on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2579

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- A worker monitors the progress of the retraction of the mobile service tower, or gantry, from the Delta II rocket on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2581

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket stands ready for launch following rollback of the mobile service tower, or gantry, on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2580

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket stands ready for launch following rollback of the mobile service tower, or gantry, on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd2577

NASA Image and Video Library

2007-09-26

KENNEDY SPACE CENTER, FLA. -- The Delta II rocket is revealed as the mobile service tower, or gantry (at left), is retracted on Launch Pad 17B at Cape Canaveral Air Force Station. Starting with a boost from this higher thrust version of the Delta II rocket, the Dawn spacecraft will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. To carry out its scientific mission during its nearly decade-long mission, Dawn will carry a visible camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron spectrometer, whose data will be used in combination to characterize these bodies. In addition to the three instruments, radiometric and optical navigation data will provide data relating to the gravity field, and thus, bulk properties and internal structure of the two bodies. Data returned from the Dawn spacecraft could provide opportunities for significant breakthroughs in our knowledge of how the solar system formed. Launch is targeted for Sept. 27 during a window that extends from 7:20 to 7:49 a.m. EDT. Photo credit: NASA/Kim Shiflett

KSC-07pd1311

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the first stage of a Delta II rocket is being raised to a vertical position before being lifted into the mobile service tower. The rocket is the launch vehicle for the Dawn spacecraft, targeted for liftoff on June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Amanda Diller

KSC-07pd1315

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- In the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station, the Delta II first stage is ready to receive the upper stages and solid rocket boosters for launch. The rocket is the launch vehicle for the Dawn spacecraft, targeted for liftoff on June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Amanda Diller

Dawn Mission: A Journey in Space and Time

NASA Technical Reports Server (NTRS)

Russell, C. T.; Coradini, A.; DeSanctis, M. C.; Feldman, W. C.; Jaumann, R.; Konopliv, A. S.; McCord, T. B.; McFadden, L. A.; McSween, H. Y.; Mottola, S.

2003-01-01

By successively orbiting both 4 Vesta and 1 Ceres the Dawn mission directly addresses the longstanding goals of NASA and the planetary community to understand the origin and evolution of the solar system by obtaining geophysical and geochemical data on diverse main belt asteroids. Ceres and Vesta are two complementary terrestrial protoplanets (one apparently "wet" and one "dry"), whose accretion was terminated by the formation of Jupiter. Ceres is little changed since it formed in the early solar system, while Vesta has experienced significant heating and differentiation. Both have remained intact over the age of the solar system, thereby retaining a record of events and processes from the time of planet formation. Detailed study of the geophysics and geochemistry of these two bodies provides critical benchmarks for the early solar system conditions and processes that shaped its subsequent evolution. Dawn provides the missing context for both primitive and evolved meteoritic data, thus playing a central role in understanding terrestrial planet formation and the evolution of the asteroid belt. Dawn is to be launched in May 2006 arriving at Vesta in 2010 and Ceres in 2014, stopping at each to make 11 months of orbital measurements. The spacecraft uses solar electric propulsion both in cruise and in orbit to make most efficient use of its xenon propellant. The spacecraft carries a framing camera, visible and infrared mapping spectrometer, gamma ray/neutron spectrometer, a laser altimeter, magnetometer, and radio science.

KSC-07pd2591

NASA Image and Video Library

2007-09-27

KENNEDY SPACE CENTER, FLA. -- Against a backdrop of clouds on the horizon, the Delta II rocket carrying NASA's Dawn spacecraft rises from the smoke and fire on the launch pad to begin its 1.7-billion-mile journey through the inner solar system to study a pair of asteroids. Liftoff was at 7:34 a.m. EDT from Pad 17-B at Cape Canaveral Air Force Station. Dawn is the ninth mission in NASA's Discovery Program. The spacecraft will be the first to orbit two planetary bodies, asteroid Vesta and dwarf planet Ceres, during a single mission. Vesta and Ceres lie in the asteroid belt between Mars and Jupiter. It is also NASA's first purely scientific mission powered by three solar electric ion propulsion engines. Photo credit: NASA/Sandra Joseph & Rafael Hernandez

The Faces of Vesta

NASA Image and Video Library

2010-10-08

NASA Hubble Space Telescope snapped these images of the asteroid Vesta in preparation for the Dawn spacecraft visit in 2011. The images show the difference in brightness and color on the asteroid surface.

Wall of Rheasilvia

NASA Image and Video Library

2012-03-21

This still from an animation made from data obtained by NASA Dawn spacecraft shows the topography of a portion of the wall and interior of the Rheasilvia impact basin in asteroid Vesta south-polar region.

Canuleia Crater

NASA Image and Video Library

2012-04-24

This image from NASA Dawn spacecraft of asteroid Vesta shows Canuleia crater, a large, irregularly shaped crater. Other interesting features of Canuleia include the diffuse bright material that is both inside and outside of its rim.

High-resolution Ceres Low Altitude Mapping Orbit Atlas derived from Dawn Framing Camera images

NASA Astrophysics Data System (ADS)

Roatsch, Th.; Kersten, E.; Matz, K.-D.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

2017-06-01

The Dawn spacecraft Framing Camera (FC) acquired over 31,300 clear filter images of Ceres with a resolution of about 35 m/pxl during the eleven cycles in the Low Altitude Mapping Orbit (LAMO) phase between December 16 2015 and August 8 2016. We ortho-rectified the images from the first four cycles and produced a global, high-resolution, uncontrolled photomosaic of Ceres. This global mosaic is the basis for a high-resolution Ceres atlas that consists of 62 tiles mapped at a scale of 1:250,000. The nomenclature used in this atlas was proposed by the Dawn team and was approved by the International Astronomical Union (IAU). The full atlas is available to the public through the Dawn Geographical Information System (GIS) web page [http://dawngis.dlr.de/atlas] and will become available through the NASA Planetary Data System (PDS) (http://pdssbn.astro.umd.edu/).

Dawn Survey Orbit Image 43

NASA Image and Video Library

2015-08-07

This image, taken by NASA's Dawn spacecraft, shows a portion of the southern hemisphere of dwarf planet Ceres from an altitude of 2,700 miles (4,400 kilometers). The image, with a resolution of 1,400 feet (410 meters) per pixel, was taken on June 25, 2015. The image was obtained on June 25, 2015 from an altitude of 2,700 miles (4,400 kilometers) above Ceres and has a resolution of 1,400 feet (410 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19616

Dawn HAMO Image 53

NASA Image and Video Library

2015-11-05

This image, taken by NASA's Dawn spacecraft, shows the surface of dwarf planet Ceres from an altitude of 915 miles (1,470 kilometers) around mid-latitudes. The image was taken on Sept. 28, 2015, and has a resolution of 450 feet (140 meters) per pixel. The unusual mountain Ahuna Mons is featured in this image, named for the traditional post-harvest festival of the Sumi tribe of Nagaland, India. It is 4 miles (6 kilometers) tall and 12 miles (20 kilometers) in diameter. http://photojournal.jpl.nasa.gov/catalog/PIA19995

KSC-07pd1612

NASA Image and Video Library

2007-06-21

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers check the attachments of the Dawn spacecraft onto the upper stage booster. The two elements are being mated for launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1310

NASA Image and Video Library

2007-05-28

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, the first stage of a Delta II rocket is being raised off its transporter into a vertical position. Once vertical, the rocket will be lifted up into the mobile service tower. The rocket is the launch vehicle for the Dawn spacecraft, targeted for liftoff on June 30. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Amanda Diller

KSC-07pd1610

NASA Image and Video Library

2007-06-21

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers help guide the Dawn spacecraft toward the upper stage booster below. The two elements will be mated for launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1324

NASA Image and Video Library

2007-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, one of nine solid rocket boosters is raised off the transporter. It will be lifted into the mobile service tower for attachment around the Delta II first stage. The SRB is one of nine to be attached for the launch of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Jim Grossmann

KSC-07pd1613

NASA Image and Video Library

2007-06-21

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers secure the attachments of the Dawn spacecraft onto the upper stage booster. The two elements are being mated for launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1332

NASA Image and Video Library

2007-05-29

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-B at Cape Canaveral Air Force Station, a third solid rocket booster is raised to a vertical position. It will be lifted into the mobile service tower for attachment around the Delta II first stage. The SRB is one of nine to be attached for the launch of the Dawn spacecraft. Dawn's mission is to explore two of the asteroid belt's most intriguing and dissimilar occupants: asteroid Vesta and the dwarf planet Ceres. Photo credit: NASA/Jim Grossmann

Evidence for ground-ice occurrence on asteroid Vesta using Dawn bistatic radar observations

NASA Astrophysics Data System (ADS)

Palmer, E. M.; Heggy, E.; Kofman, W. W.

2017-12-01

From 2011 to 2012, the Dawn spacecraft orbited asteroid Vesta, the first of its two targets in the asteroid belt, and conducted the first bistatic radar (BSR) experiment at a small-body, during which Dawn's high-gain communications antenna is used to transmit radar waves that scatter from Vesta's surface toward Earth at high incidence angles just before and after occultation of the spacecraft behind the asteroid. Among the 14 observed mid-latitude forward-scatter reflections, the radar cross section ranges from 84 ± 8 km2 (near Saturnalia Fossae) to 3,588 ± 200 km2 (northwest of Caparronia crater), implying substantial spatial variation in centimeter- to decimeter-scale surface roughness. The compared distributions of surface roughness and subsurface hydrogen concentration [H]—measured using data from Dawn's BSR experiment and Gamma Ray and Neutron Spectrometer (GRaND), respectively—reveal the occurrence of heightened subsurface [H] with smoother terrains that cover tens of square kilometers. Furthermore, unlike on the Moon, we observe no correlation between surface roughness and surface ages on Vesta—whether the latter is derived from lunar or asteroid-flux chronology [Williams et al., 2014]—suggesting that cratering processes alone are insufficient to explain Vesta's surface texture at centimeter-to-decimeter scales. Dawn's BSR observations support the hypothesis of transient melting, runoff and recrystallization of potential ground-ice deposits, which are postulated to flow along fractures after an impact, and provide a mechanism for the smoothing of otherwise rough, fragmented impact ejecta. Potential ground-ice presence within Vesta's subsurface was first proposed by Scully et al. [2014], who identified geomorphological evidence for transient water flow along several of Vesta's crater walls using Dawn Framing Camera images. While airless, differentiated bodies such as Vesta and the Moon are thought to have depleted their initial volatile content during the process of differentiation, evidence to the contrary is continuing to change our understanding of the distribution and preservation of volatiles during planetary formation in the early solar system.

Fresh Dark Ray Crater

NASA Image and Video Library

2011-10-15

The crater on asteroid Vesta shown in this image from NASA Dawn spacecraft was emplaced onto the ejecta blanket of two large twin craters. Commonly, rays from impact craters are brighter than the surrounding surface.

The Dawn of Vesta Science

NASA Technical Reports Server (NTRS)

Garner, Charles E.; Rayman, Marc D.; Brophy, John R.; Mikes, Steven C.

2011-01-01

The Dawn mission is part of NASA's Discovery Program and has as its goal the scientific exploration of the two most massive main-belt asteroids, Vesta and Ceres. The Dawn spacecraft was launched from the Cape Canaveral Air Force Station on September 27, 2007 on a Delta-II 7925H-9.5 (Delta-II Heavy) rocket that placed the 1218-kg spacecraft onto an Earth-escape trajectory. On-board the spacecraft is an ion propulsion system (IPS) developed at the Jet Propulsion Laboratory which will provide a total ?V of 11.3 km/s for the heliocentric transfer to Vesta, orbit capture at Vesta, transfer between Vesta science orbits, departure and escape from Vesta, heliocentric transfer to Ceres, orbit capture at Ceres, and transfer between Ceres science orbits. Fullpower thrusting from December 2007 through October 2008 was used to successfully target a Mars gravity assist flyby in February 2009 that provided an additional ?V of 2.6 km/s. Deterministic thrusting for the heliocentric transfer to Vesta resumed in June 2009 and concluded with orbit capture at Vesta on July 16, 2011. An additional 210 hours of IPS thrusting was used to enter the first Vesta science orbit, called Survey orbit, on August 3, 2011 at an altitude of approximately 2,735 km. To date the IPS has been operated for 23,621 hours, consumed approximately 252 kg of xenon, and provided a delta-V of approximately 6.7 km/s. The IPS performance characteristics are very close to the expected performance based on analysis and testing performed pre-launch. The only significant issue in over the almost four years of IPS operations in flight was the temporary failure of a valve driver board in the Digital Control and Interface Unit-1 (DCIU-1), resulting in a loss of thrust of approximately 29 hours. Thrusting operations resumed after switching to DCIU-2, and power cycling conducted after orbit capture restored DCIU-1 to full functionality. After about three weeks of Survey orbit operations the IPS will be used to transfer the spacecraft to the other planned science orbit altitudes. After approximately one year of science operations the IPS will be used for escape from Vesta and then for thrusting to Ceres with a planned arrival date at Ceres in February 2015. This paper provides an overview of Dawn's mission objectives and the results of Dawn IPS mission operations through the start of science operations at Vesta.

Flight Over Ceres

NASA Image and Video Library

2016-01-28

This animated flight over Ceres explores the most prominent craters, as well as the mountain Ahuna Mons. The movie shows Ceres in enhanced color, using images taken by the NASA's Dawn spacecraft as it orbited the dwarf planet.

Occia Crater

NASA Image and Video Library

2012-05-10

This image from NASA Dawn spacecraft of asteroid Vesta shows Occia crater, located in Vesta Gegania quadrangle, in Vesta southern hemisphere. A distinctive butterfly pattern is seen consisting of two separate lobes of ejecta on the opposite sides.

Occator Topography

NASA Image and Video Library

2015-09-30

This view, made using images taken by NASA Dawn spacecraft, is a color-coded topographic map of Occator crater on Ceres. Blue is the lowest elevation, and brown is the highest. http://photojournal.jpl.nasa.gov/catalog/PIA19975

Observation and theory of Pc 5 waves with harmonically related transverse and compressional components

NASA Astrophysics Data System (ADS)

Takahashi, K.; Cheng, C. Z.; McEntire, R. W.; Kistler, L. M.

1990-02-01

The properties of 23 magnetic pulsation events observed by the AMPTE CCE spacecraft are studied. These events are selected on the basis of the field magnitude which oscillated at the second harmonic of a simultaneously present transverse oscillation. The events have a second harmonic period of 80-600 s (roughly the Pc 5 range), are observed in cluster in the dawn (0300-0800 magnetic local time, MLT) and dusk (1600-2100 MLT) sectors, and are localized near the magnetic equator. Although the azimuthal wave number estimated from an ion finite Larmor radius effect, is generally large (about 50), there is a marked difference between the events observed in the dawn and dusk sectors. In the dawn sector the waves have low frequencies (1-5 mHz), indicate left-hand polarization with respect to the ambient magnetic field, and propagate eastward with respect to the spacecraft. In the dusk sector the waves have high frequencies (5-15 mHz), indicate right-hand polarization, and propagate westward. It is suggested that the waves are all westward propagating in the plasma rest frame and that local-time-dependent Doppler shift is the reason for the local time dependence of the wave properties.

Observation and theory of Pc 5 waves with harmonically related transverse and compressional components

NASA Technical Reports Server (NTRS)

Takahashi, K.; Mcentire, R. W.; Cheng, C. Z.; Kistler, L. M.

1990-01-01

The properties of 23 magnetic pulsation events observed by the AMPTE CCE spacecraft are studied. These events are selected on the basis of the field magnitude which oscillated at the second harmonic of a simultaneously present transverse oscillation. The events have a second harmonic period of 80-600 s (roughly the Pc 5 range), are observed in cluster in the dawn (0300-0800 magnetic local time, MLT) and dusk (1600-2100 MLT) sectors, and are localized near the magnetic equator. Although the azimuthal wave number estimated from an ion finite Larmor radius effect, is generally large (about 50), there is a marked difference between the events observed in the dawn and dusk sectors. In the dawn sector the waves have low frequencies (1-5 mHz), indicate left-hand polarization with respect to the ambient magnetic field, and propagate eastward with respect to the spacecraft. In the dusk sector the waves have high frequencies (5-15 mHz), indicate right-hand polarization, and propagate westward. It is suggested that the waves are all westward propagating in the plasma rest frame and that local-time-dependent Doppler shift is the reason for the local time dependence of the wave properties.

KSC-07pd1591

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians begin placing the sun shade over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1592

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians begin securing the sun shade over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1593

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians are securing the sun shade over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

Clues to Ceres' Internal Structure

NASA Image and Video Library

2017-10-26

This frame from an animation shows Ceres as seen by NASA's Dawn spacecraft from its high-altitude mapping orbit at 913 miles (1,470 kilometers) above the surface. The colorful map overlaid at right shows variations in Ceres' gravity field measured by Dawn, and gives scientists hints about the dwarf planet's internal structure. Red colors indicate more positive values, corresponding to a stronger gravitational pull than expected, compared to scientists' pre-Dawn model of Ceres' internal structure; blue colors indicate more negative values, corresponding to a weaker gravitational pull. The animation was created by projecting a map of Ceres onto a rotating sphere. The image scale is about 450 feet (140 meters) per pixel. The animations are available at https://photojournal.jpl.nasa.gov/catalog/PIA22083

Remote Sensing Measurements of the Corona with the Solar Probe

NASA Technical Reports Server (NTRS)

Habbal, Shadia Rifai; Woo, Richard

1996-01-01

Remote sensing measurements of the solar corona are indespensible for the exploration of the source and acceleration regions of the solar wind which are inaccessible to in situ plasma, paritcles and field experiments.Furthermore, imaging the solar disk and coronal from the unique vantage point of the trajectory and the proximity of the Solar Probe spacecraft, will provide the first ever opportunity to explore the small scale structures within coronal holes and streamers from viewing angles and with spatial resolutions never attained before.

NASA's Dawn Mission to Asteroid 4 Vesta

NASA Technical Reports Server (NTRS)

McFadden, Lucyann A.

2011-01-01

NASA's Dawn Mission to asteroid 4 Vesta is part of a 13-year robotic space project designed to reveal the nature of two of the largest asteroids in the Main Asteroid Belt of our Solar System. Ceres and Vesta are two complementary terrestrial protoplanets whose accretion was probably terminated by the formation of Jupiter. They provide a bridge in our understanding between the rocky bodies of the inner solar system and the icy bodies of the outer solar system. Ceres appears to be undifferentiated Vesta has experienced significant heating and likely differentiation. Both formed very early in history of the solar system and while suffering many impacts have remained intact, thereby retaining a record of events and processes from the time of planet formation. Detailed study of the geophysics and geochemistry of these two bodies provides critical benchmarks for early solar system conditions and processes that shaped its subsequent evolution. Dawn provides the missing context for both primitive and evolved meteoritic data, thus playing a central role in understanding terrestrial planet formation and the evolution of the asteroid belt. Dawn is to he launched in 2006 arriving at Vesta in 20l0 and Ceres in 2014, stopping at each to make 11 months of orbital measurements. The spacecraft uses solar electric propulsion, both in cruise and in orbit, to make most efficient use of its xenon propellant. The spacecraft carries a framing camera, visible and infrared mapping spectrometer, gamma ray/neutron magnetometer, and radio science.

Dark Hill on Asteroid Vesta Movie

NASA Image and Video Library

2011-12-06

This still from a movie shows an image taken by NASA Dawn spacecraft layered on a digital terrain model of an unusual hill containing a dark-rayed impact crater and nearby dark deposit on asteroid Vesta.

Animation of Ceres

NASA Image and Video Library

2015-01-19

This frame from an animation comes from NASA Dawn spacecraft as it observed Ceres for an hour on Jan. 13, 2015, from a distance of 238,000 miles 383,000 kilometers. http://photojournal.jpl.nasa.gov/catalog/PIA19168

A Valentine from Vesta

NASA Image and Video Library

2012-02-14

This image from NASA Dawn spacecraft, is based on a framing camera image that is overlain by a color-coded height representation of topography. This heart-shaped hollow is roughly 10 kilometers 6 miles across at its widest point.

Shape and Gravity of Vesta South Pole

NASA Image and Video Library

2012-04-25

This set of images from NASA Dawn spacecraft shows topography of the southern hemisphere of the giant asteroid Vesta and a map of Vesta gravity variations that have been adjusted to account for Vesta shape.

Topography of Vesta Surface

NASA Image and Video Library

2011-08-26

This view of the topography of asteroid Vesta surface is composed of several images obtained with the framing camera on NASA Dawn spacecraft on August 6, 2011. The image mosaic is shown superimposed on a digital terrain model.

Dawn Survey Orbit Image 42

NASA Image and Video Library

2015-08-06

This image of Ceres, taken by NASA's Dawn spacecraft, features a large, steep-sided mountain and several intriguing bright spots. The mountain's height is estimated to be about 4 miles (6 kilometers), which is a revision of the previous estimate of 3 miles (5 kilometers). It is the highest point seen on Ceres so far. The image was obtained on June 25, 2015 from an altitude of 2,700 miles (4,400 kilometers) above Ceres and has a resolution of 1,400 feet (410 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19615

KSC-07pd1609

NASA Image and Video Library

2007-06-21

KENNEDY SPACE CENTER, FLA. -- At Astrotech, workers check the movement of the Dawn spacecraft, at left, toward the upper stage booster at right. The two elements will be mated for launch. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1487

NASA Image and Video Library

2007-06-11

KENNEDY SPACE CENTER, FLA. -- Three solid rocket boosters are suspended in the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station for mating to the Delta II first stage for launch of the Dawn spacecraft. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is targeted for July 7. Photo credit: NASA/Jim Grossmann

KSC-07pd1477

NASA Image and Video Library

2007-06-11

KENNEDY SPACE CENTER, FLA. -- This closeup shows four of the nine solid rocket boosters being mated to the Delta II first stage on Launch Pad 17-B at Cape Canaveral Air Force Station for launch of the Dawn spacecraft. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is targeted for July 7. Photo credit: NASA/Jim Grossmann

KSC-07pd1483

NASA Image and Video Library

2007-06-11

KENNEDY SPACE CENTER, FLA. -- A solid rocket booster is lifted into the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station. The booster will be mated to the Delta II first stage for launch of the Dawn spacecraft. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is targeted for July 7. Photo credit: NASA/Jim Grossmann

KSC-07pd1479

NASA Image and Video Library

2007-06-11

KENNEDY SPACE CENTER, FLA. -- Another solid rocket booster arrives on Launch Pad 17-B at Cape Canaveral Air Force Station to be mated to the Delta II first stage. The Delta is the launch vehicle for the Dawn spacecraft. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch 4.5 billion years ago by investigating in detail two of the largest asteroids, Ceres and Vesta. They reside between Mars and Jupiter in the asteroid belt. Launch is targeted for July 7. Photo credit: NASA/Jim Grossmann

Successive Formation of Impact Craters

NASA Image and Video Library

2012-02-16

This image from NASA Dawn spacecraft shows two overlapping impact craters on asteroid Vesta. The rims of the craters are both reasonably fresh but the larger crater must be older because the smaller crater cuts across the larger crater rim.

Aricia Tholus

NASA Image and Video Library

2012-02-22

This image from NASA Dawn spacecraft shows Aricia Tholus, a dark hill located in asteroid Vesta Marcia quadrangle. Tholus is a word used to describe a small dome-like mountain or hill. Aricia was the name of a city in ancient Italy.

Dense Region of Impact Craters

NASA Image and Video Library

2011-09-23

NASA Dawn spacecraft obtained this image of the giant asteroid Vesta with its framing camera on Aug. 14 2011. This image was taken through the camera clear filter. The image has a resolution of about 260 meters per pixel.

Vesta Surface at High Resolution: Dominated by Impact Craters

NASA Image and Video Library

2012-02-13

This image from NASA Dawn spacecraft shows a large number of craters, formed by collisions into the surface of asteroid Vesta. The relatively large circular depressions in this image are older, heavily degraded impact craters.

Small Scale Features at Vesta South Pole

NASA Image and Video Library

2011-10-01

This image from NASA Dawn spacecraft shows a raised mound material overlying the brighter material that makes up the floor of the south polar depression of asteroid Vesta. Many small scale craters are clear in this image.

Topography and Albedo Image of Grooved Terrain on Vesta

NASA Image and Video Library

2011-11-29

These images from NASA Dawn spacecraft show part of the grooved terrain in asteroid Vesta Pinaria quadrangle, which is in the southern hemisphere. Large-scale grooves and depressions can be seen running diagonally across the image.

A New Spin on Vesta

NASA Image and Video Library

2010-10-08

Hubble Wide Field Camera 3 observed the potato-shaped asteroid in preparation for the visit by NASA Dawn spacecraft in 2011. This is one frame from a movie showing the difference in brightness and color on the asteroid surface.

Regolith Depth, Mobility, and Variability on Vesta from Dawn's Low Altitude Mapping Orbit

NASA Technical Reports Server (NTRS)

Denevi, B. W.; Coman, E. I.; Blewett, D. T.; Mittlefehldt, D. W.; Buczkowski, D. L.; Combe, J.-P.; De Sanctis, M. C.; Jaumann, R.; Li, J.-Y.; Marchi, S.;

Dawn Orbit Determination Team: Modeling and Fitting of Optical Data at Vesta

NASA Technical Reports Server (NTRS)

Kennedy, Brian; Abrahamson, Matt; Ardito, Alessandro; Haw, Robert; Mastrodemos, Nicholas; Nandi, Sumita; Park, Ryan; Rush, Brian; Vaughan, Andrew

2013-01-01

The Dawn spacecraft was launched on September 27th, 2007. Its mission is to consecutively rendezvous with and observe the two largest bodies in the main asteroid belt, Vesta and Ceres. It has already completed over a year's worth of direct observations of Vesta (spanning from early 2011 through late 2012) and is currently on a cruise trajectory to Ceres, where it will begin scientific observations in mid-2015. Achieving this data collection required careful planning and execution from all Dawn operations teams. Dawn's Orbit Determination (OD) team was tasked with reconstruction of the as-flown trajectory as well as determination of the Vesta rotational rate, pole orientation and ephemeris, among other Vesta parameters. Improved knowledge of the Vesta pole orientation, specifically, was needed to target the final maneuvers that inserted Dawn into the first science orbit at Vesta. To solve for these parameters, the OD team used radiometric data from the Deep Space Network (DSN) along with optical data reduced from Dawn's Framing Camera (FC) images. This paper will de-scribe the initial determination of the Vesta ephemeris and pole using a combination of radiometric and optical data, and also the progress the OD team has made since then to further refine the knowledge of Vesta's body frame orientation and rate with these data.

Kupalo Crater from LAMO

NASA Image and Video Library

2016-01-12

This image from NASA's Dawn spacecraft shows Kupalo Crater, one of the youngest craters on Ceres. The crater has bright material exposed on its rim and walls, which could be salts. Its flat floor likely formed from impact melt and debris. Kupalo, which measures 16 miles (26 kilometers) across and is located at southern mid-latitudes, is named for the Slavic god of vegetation and harvest. Kupalo was imaged earlier in Dawn's science mission at Ceres -- during Survey orbit (see PIA19624) and from the high altitude mapping orbit, or HAMO (see PIA20124). Dawn took this image on Dec. 21 from its low-altitude mapping orbit (LAMO) at an approximate altitude of 240 miles (385 kilometers) above Ceres. The image resolution is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20192

KSC-07pd1596

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians secure all sides of the sun shade over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1589

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians lift the sun shade to be installed over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1588

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, a technician looks at the sun shade (foreground) to be installed over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1590

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, technicians lift the sun shade toward the Dawn spacecraft to install it on the high gain antenna. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1595

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, a technician secures one side of the sun shade over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1597

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At At Astrotech, the Dawn spacecraft is on display with the recently installed sun shade over the high gain antenna. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

KSC-07pd1594

NASA Image and Video Library

2007-06-19

KENNEDY SPACE CENTER, FLA. -- At Astrotech, a technician secures one side of the sun shade over the high gain antenna on the Dawn spacecraft. Made of germanium kapton, the shade, which is RF transparent, is placed over the sensitive antenna to reflect and emit harmful solar radiation to prevent the antenna from being excessively heated. Dawn is scheduled to launch July 7 from Pad 17-B on Cape Canaveral Air Force Station. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/George Shelton

Dawn Auroral Breakup at Saturn Initiated by Auroral Arcs: UVIS/Cassini Beginning of Grand Finale Phase

NASA Astrophysics Data System (ADS)

Radioti, A.; Grodent, D.; Yao, Z. H.; Gérard, J.-C.; Badman, S. V.; Pryor, W.; Bonfond, B.

2017-12-01

We present Cassini auroral observations obtained on 11 November 2016 with the Ultraviolet Imaging Spectrograph at the beginning of the F-ring orbits and the Grand Finale phase of the mission. The spacecraft made a close approach to Saturn's southern pole and offered a remarkable view of the dayside and nightside aurora. With this sequence we identify, for the first time, the presence of dusk/midnight arcs, which are azimuthally spread from high to low latitudes, suggesting that their source region extends from the outer to middle/inner magnetosphere. The observed arcs could be auroral manifestations of plasma flows propagating toward the planet from the magnetotail, similar to terrestrial "auroral streamers." During the sequence the dawn auroral region brightens and expands poleward. We suggest that the dawn auroral breakup results from a combination of plasma instability and global-scale magnetic field reconfiguration, which is initiated by plasma flows propagating toward the planet. Alternatively, the dawn auroral enhancement could be triggered by tail magnetic reconnection.

Dawn XMO2 Image 32

NASA Image and Video Library

2017-02-10

This image captures the day-night boundary, or terminator, in the north polar region of Ceres. The north pole itself, which lies just slightly left of center in this view, is barely sunlit, even though the local time at its location is 11:06 a.m. The north polar region is densely cratered, and some crater floors remain in permanent shadow. Some of those permanently shadowed craters contain bright deposits, as described in a 2016 Nature Astronomy study by scientists on NASA's Dawn mission. The best example of these bright deposits was found by Dawn in an unnamed and geologically young, 4-mile- (6-kilometer-) wide crater located at 86.2 degrees north latitude, 80.0 degrees east longitude (the small, sharply defined crater just right of center). This picture was obtained by the Dawn spacecraft on October 17, 2016, from an altitude of about 923 miles (1,486 kilometers). The image is located at 89 degrees north latitude, 86 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA21397

A Terminator View from Mercury Flyby 2

NASA Image and Video Library

2009-04-21

This high-resolution NAC image shows a view of Mercury dawn terminator, the division between the sunlit dayside and dark nightside of the planet, as seen as the MESSENGER spacecraft departed the planet during the mission second Mercury flyby.

Dark Areas in Cratered Terrain on Vesta

NASA Image and Video Library

2011-10-14

In this image from NASA Dawn spacecraft, a number of small dark areas, mostly clustered in the center and left of the image, are visible in asteroid Vesta cratered landscape. A lot of these dark patches are small impact craters.

Side by Side Views of a Dark Hill

NASA Image and Video Library

2011-09-02

NASA Dawn spacecraft obtained these side-by-side views of a dark hill of the surface of asteroid Vesta with its framing camera on August 19, 2011. The images have a resolution of about 260 meters per pixel.

Vesta Partly Shadowed Northern Regions

NASA Image and Video Library

2012-06-01

This image from NASA Dawn spacecraft shows a part of asteroid Vesta surface reasonably far north into the northern hemisphere which appears washed out because it has been stretched to make features visible that would otherwise be too dark to see.

False-Color Image of an Impact Crater on Vesta

NASA Image and Video Library

2011-08-24

NASA Dawn spacecraft obtained this false-color image right of an impact crater in asteroid Vesta equatorial region with its framing camera on July 25, 2011. The view on the left is from the camera clear filter.

Fresh Impact Craters on Asteroid Vesta

NASA Image and Video Library

2011-12-06

This image combines two separate views of the giant asteroid Vesta obtained by NASA Dawn spacecraft. The fresh impact craters in this view are located in the south polar region, which has been partly covered by landslides from the adjacent crater.

Vesta Cratered Landscape: Double Crater and Craters with Bright Ejecta

NASA Image and Video Library

2011-11-23

This image from NASA Dawn spacecraft is dominated by a double crater which may have been formed by the simultaneous impact of a binary asteroid. Binary asteroids are asteroids that orbit their mutual center of mass.

Apparent Brightness and Topography Images of Sossia and Canuleia Craters

NASA Image and Video Library

2012-07-03

These images from NASA Dawn spacecraft are located in asteroid Vesta Urbinia quadrangle, in Vesta southern hemisphere. Rays of bright material surround Canuleia crater and rays of dark material extend from the top part of Sossia crater.

Dark Material Associated with and between Craters

NASA Image and Video Library

2011-11-18

This image from NASA Dawn spacecraft shows areas of dark material which are both associated with impact craters and between these craters on asteroid Vesta. Dark material is seen cropping out of the rims and sides of the larger craters.

Apparent Brightness and Topography Images of Vibidia Crater

NASA Image and Video Library

2012-03-09

The left-hand image from NASA Dawn spacecraft shows the apparent brightness of asteroid Vesta surface. The right-hand image is based on this apparent brightness image, with a color-coded height representation of the topography overlain onto it.

Topography of Troughs on Vesta

NASA Image and Video Library

2011-08-23

This view of the topography of asteroid Vesta surface is composed of several images obtained with the clear filter in the framing camera on NASA Dawn spacecraft on August 6, 2011. The image has a resolution of about 260 meters per pixel.

Simplified Ion Thruster Xenon Feed System for NASA Science Missions

NASA Technical Reports Server (NTRS)

Snyder, John Steven; Randolph, Thomas M.; Hofer, Richard R.; Goebel, Dan M.

2009-01-01

The successful implementation of ion thruster technology on the Deep Space 1 technology demonstration mission paved the way for its first use on the Dawn science mission, which launched in September 2007. Both Deep Space 1 and Dawn used a "bang-bang" xenon feed system which has proven to be highly successful. This type of feed system, however, is complex with many parts and requires a significant amount of engineering work for architecture changes. A simplified feed system, with fewer parts and less engineering work for architecture changes, is desirable to reduce the feed system cost to future missions. An attractive new path for ion thruster feed systems is based on new components developed by industry in support of commercial applications of electric propulsion systems. For example, since the launch of Deep Space 1 tens of mechanical xenon pressure regulators have successfully flown on commercial spacecraft using electric propulsion. In addition, active proportional flow controllers have flown on the Hall-thruster-equipped Tacsat-2, are flying on the ion thruster GOCE mission, and will fly next year on the Advanced EHF spacecraft. This present paper briefly reviews the Dawn xenon feed system and those implemented on other xenon electric propulsion flight missions. A simplified feed system architecture is presented that is based on assembling flight-qualified components in a manner that will reduce non-recurring engineering associated with propulsion system architecture changes, and is compared to the NASA Dawn standard. The simplified feed system includes, compared to Dawn, passive high-pressure regulation, a reduced part count, reduced complexity due to cross-strapping, and reduced non-recurring engineering work required for feed system changes. A demonstration feed system was assembled using flight-like components and used to operate a laboratory NSTAR-class ion engine. Feed system components integrated into a single-string architecture successfully operated the engine over the entire NSTAR throttle range over a series of tests. Flow rates were very stable with variations of at most 0.2%, and transition times between throttle levels were typically 90 seconds or less with a maximum of 200 seconds, both significant improvements over the Dawn bang-bang feed system.

Animation of Ceres

NASA Image and Video Library

2015-02-06

This still from an animation showcases a series of images NASA Dawn spacecraft took on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles 145,000 kilometers from the dwarf planet. http://photojournal.jpl.nasa.gov/catalog/PIA19179

Large Subdued and Small Fresh Craters

NASA Image and Video Library

2012-03-27

This image from NASA Dawn spacecraft shows many large subdued craters that have smaller, younger craters on top of them on asteroid Vesta. There are two large subdued craters in the center of the image, which have very degraded and rounded rims.

Sharp Crater Rim with Dark Material and Boulders

NASA Image and Video Library

2012-03-02

This image from NASA Dawn spacecraft shows part of the sharp, fresh rim of a large crater on asteroid Vesta. There is some bright material slumping towards the center of this crater but this is mostly overshadowed by the dark material.

Asymmetric Magnetosphere Deformation Driven by Hot Flow Anomaly(ies)

NASA Technical Reports Server (NTRS)

Safrankova, J.; Goncharov, O.; Nemecek, Z.; Prech, L.; Sibeck, D. G.

2012-01-01

We present a case study of a large deformation of the magnetopause on November 26, 2008. The investigation is based on observations of five THEMIS spacecraft located at the dawn flank in the magnetosphere and magnetosheath, on Cluster measurements at the dusk magnetosheath, and is supported by ACE solar wind monitoring. The main revelation of our study is that the interaction of the IMF discontinuity with the bow shock creates either one very elongated hot flow anomaly (HFA) or a pair of them that is (are) simultaneously observed at both flanks. Whereas the dusk HFA is weak and does not cause observable deformation of the magnetopause, the pressure variations connected with the dawn HFA lead to a magnetopause displacement by approx. = 5 R(sub E) outward from its nominal position. This is followed by a rapid inward motion of the magnetopause approx. = 4 R(sub E) inward with respect to the model location. The surface deformation is so large that the outermost THEMIS spacecraft was in the magnetosphere, whereas the spacecraft located 9 R(sub E) inbound entered into the magnetosheath at the same time. The whole event lasted about 5 minutes.

Ahuna Mons: Side View

NASA Image and Video Library

2016-09-01

Ceres' lonely mountain, Ahuna Mons, is seen in this simulated perspective view. The elevation has been exaggerated by a factor of two. The view was made using enhanced-color images from NASA's Dawn mission. Images taken using blue (440 nanometers), green (750 nanometers) and infrared (960 nanometers) spectral filters were combined to create the view. The spacecraft's framing camera took the images from Dawn's low-altitude mapping orbit, from an altitude of 240 miles (385 kilometers) in August 2016. The resolution of the component images is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20915

Oxo Crater: Side View

NASA Image and Video Library

2016-09-01

Ceres' lonely mountain, Ahuna Mons, is seen in this simulated perspective view. The elevation has been exaggerated by a factor of two. The view was made using enhanced-color images from NASA's Dawn mission. Images taken using blue (440 nanometers), green (750 nanometers) and infrared (960 nanometers) spectral filters were combined to create the view. The spacecraft's framing camera took the images from Dawn's low-altitude mapping orbit, from an altitude of 240 miles (385 kilometers) in August 2016. The resolution of the component images is 120 feet (35 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20915

Using Dawn to Observe SEP Events Past 2 AU

NASA Astrophysics Data System (ADS)

Villarreal, M. N.; Russell, C. T.; Prettyman, T. H.

2017-12-01

The launch of the STEREO spacecraft provided much insight into the longitudinal and radial distribution of solar energetic particles (SEPs) relative to their origin site. However, almost all of the observations of SEP events have been made exclusively near 1 AU. The Dawn mission, which orbited around Vesta before arriving at Ceres, provides an opportunity to analyze these events at much further distances. Although Dawn's Gamma Ray and Neutron Detector (GRaND) is not optimized for SEP characterization, it is sensitive to protons greater than 4 MeV, making it capable of detecting a solar energetic particle event in its vicinity. Solar energetic particles in this area of the solar system are important as they are believed to cause sputtering at bodies such as Ceres and comets (Villarreal et al., 2017; Wurz et al., 2015). In this study, we use Dawn's GRaND data from 2011-2015 when Dawn was at distances between 2-3 AU. We compare the SEP events seen by Dawn with particle measurements at 1 AU using STEREO, Wind, and ACE to understand how the SEP events evolved past 1 AU.References: Villarreal, M. N., et al. (2017), The dependence of the Cerean exosphere on solar energetic particle events, Astrophys. J. Lett., 838, L8.Wurz, P. et al. (2015), Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko, A&A, 583, A22.

Earth horizon modeling and application to static Earth sensors on TRMM spacecraft

NASA Technical Reports Server (NTRS)

Keat, J.; Challa, M.; Tracewell, D.; Galal, K.

1995-01-01

Data from Earth sensor assemblies (ESA's) often are used in the attitude determination (AD) for both spinning and Earth-pointing spacecraft. The ESA's on previous such spacecraft for which the ground-based AD operation was performed by the Flight Dynamics Division (FDD) used the Earth scanning method. AD on such spacecraft requires a model of the shape of the Earth disk as seen from the spacecraft. AD accuracy requirements often are too severe to permit Earth oblateness to be ignored when modeling disk shape. Section 2 of this paper reexamines and extends the methods for Earth disk shape modeling employed in AD work at FDD for the past decade. A new formulation, based on a more convenient Earth flatness parameter, is introduced, and the geometric concepts are examined in detail. It is shown that the Earth disk can be approximated as an ellipse in AD computations. Algorithms for introducing Earth oblateness into the AD process for spacecraft carrying scanning ESA's have been developed at FDD and implemented into the support systems. The Tropical Rainfall Measurement Mission (TRMM) will be the first spacecraft with AD operation performed at FDD that uses a different type of ESA - namely, a static one - containing four fixed detectors D(sub i) (i = 1 to 4). Section 3 of this paper considers the effect of Earth oblateness on AD accuracy for TRMM. This effect ideally will not induce AD errors on TRMM when data from all four D(sub i) are present. When data from only two or three D(sub i) are available, however, a spherical Earth approximation can introduce errors of 0.05 to 0.30 deg on TRMM. These oblateness-induced errors are eliminated by a new algorithm that uses the results of Section 2 to model the Earth disk as an ellipse.

Dawn at Vesta: Characterizing a minor planet

NASA Astrophysics Data System (ADS)

Pieters, C.; Russell, C.; Raymond, C.; Dawn Team

2014-07-01

The Dawn spacecraft arrived at Vesta in July 2011, spent more than a year exploring the surface with orbital instruments, and is now on its way to Ceres to do the same [1]. Beginning the investigations at Vesta, we were in the unique position of having what we believed to be samples from the surface (the HED family of meteorites) to guide our planning of scientific exploration. We also had telescopic spectra of Vesta that linked it to the meteorites [2] and had spatially resolved images of Vesta from HST [3] that indicated variations exist across the surface, and that an enormous depression occurs at the south pole. Since the HED meteorites show evidence of early melting and differentiation, we expected an ancient evolved anhydrous surface, perhaps similar to that of the Moon complete with early magma ocean. Although the Moon has often been considered a small body 'end member' that can be used to study early terrestrial planet evolution, with the year-long exploration of Vesta by Dawn, we now have extensive information for an even smaller differentiated planetary body with which to compare and test models and paradigms. We now know that both bodies are heavily cratered and exhibit at least one enormous basin that models predict should have excavated (and possibly exposed) the mantle [4]. Nevertheless, although compositional diversity is found on both, evidence for mantle material has been illusive. These two airless differentiated silicate bodies are ancient and essentially (but not completely) anhydrous. Regionally coherent areas containing H as well as OH are identified across the surface of Vesta [5] but exhibit no apparent relation to OH recently detected on the Moon [6]. Instead, Vesta's hydrated areas are spatially correlated with low-albedo regions, suggesting an exogeneous source (such as delivery by and mixing with carbonaceous chondritic material) [5,7]. Vesta exhibits its own style of space weathering that transforms fresh craters into background soils, one that involves regolith mixing instead of accumulation of nano-phase opaque components on surface grains [8]. The apparent dearth of nano-phase opaque coatings on regolith grains is due to a combination of factors involving Vesta's location and specific surface composition. The result is a mineralogically rich surface exposed to Dawn's sensors [9], although substantially rearranged by impact processes. Major scientific insights will continue to emerge as calibration improves for the Dawn instruments that measure spectral properties of the surface.

Review of Leading Approaches for Mitigating Hypersonic Vehicle Communications Blackout and a Method of Ceramic Particulate Injection Via Cathode Spot Arcs for Blackout Mitigation

NASA Technical Reports Server (NTRS)

Gillman, Eric D.; Foster, John E.; Blankson, Isaiah M.

2010-01-01

Vehicles flying at hypersonic velocities within the atmosphere become enveloped in a "plasma sheath" that prevents radio communication, telemetry, and most importantly, GPS signal reception for navigation. This radio "blackout" period has been a problem since the dawn of the manned space program and was an especially significant hindrance during the days of the Apollo missions. An appropriate mitigation method must allow for spacecraft to ground control and ground control to spacecraft communications through the reentry plasma sheath. Many mitigation techniques have been proposed, including but not limited to, aerodynamic shaping, magnetic windows, and liquid injection. The research performed on these mitigation techniques over the years will be reviewed and summarized, along with the advantages and obstacles that each technique will need to overcome to be practically implemented. A unique approach for mitigating the blackout communications problem is presented herein along with research results associated with this method. The novel method involves the injection of ceramic metal-oxide particulate into a simulated reentry plasma to quench the reentry plasma. Injection of the solid ceramic particulates is achieved by entrainment within induced, energetic cathode spot flows.

Dawn Arrives at Vesta: The Smallest Terrestrial Planet

NASA Astrophysics Data System (ADS)

Russell, C. T.; Raymond, C. A.; Coradini, A.; Nathues, A.; De Sanctis, M. C.; Prettyman, T. H.; Jaumann, R.; McSween, H. Y.; McCord, T. B.; Keller, H. U.; Rayman, M.

2011-12-01

The Dawn Mission is a revolutionary concept in planetary exploration. Within the cost cap of a low-cost Discovery mission, a spacecraft has been flown to the main asteroid belt and been put into orbit around its second most massive body, 4 Vesta. Vesta was clearly beginning its march to planet-hood when its accretion stopped, most probably by the formation of Jupiter. Dawn's exploration is enabled by an ion propulsion system that will not only allow Dawn to descend to 200 km altitude, but to leave Vesta, travel to and orbit 1 Ceres in 2015 and map this largest main belt asteroid, a dwarf planet. The initial images of the surface of Vesta have been astounding. They reveal the diverse geochemical processes driven by the internal heat of this 530 km diameter body and titanic forces that have battered Vesta for over 4.65 billion years. A large southern impact structure, troughs ringing the equator, striped craters, dark albedo features contrasting with very high albedo features and a richly colored surface distinguish this most unusual small world.

Animation of Ceres on Approach

NASA Image and Video Library

2015-02-04

This is a frame from an animation showcasing a series of images NASA Dawn spacecraft took on approach to Ceres on Feb. 4, 2015 at a distance of about 90,000 miles 145,000 kilometers from the dwarf planet. http://photojournal.jpl.nasa.gov/catalog/PIA19182

Fly Over Dwarf Planet Ceres

NASA Image and Video Library

2015-06-05

Images from NASA's Dawn spacecraft's first mapping orbit, at an altitude of 8,400 miles (13,600 kilometers), as well as navigational images taken from 3,200 miles (5,100 kilometers) away. The vertical field has been exaggerated by a factor of 2. Star field added in background.

Dark and Bright Material in a Crater Wall

NASA Image and Video Library

2012-03-28

This image from NASA Dawn spacecraft shows part of a large crater that has an irregularly shaped, fresh rim and is distinctive because it has many outcrops of dark and bright material originating from its rim and from the interior slope of the crater.

Axomama Crater on Ceres

NASA Image and Video Library

2017-10-06

This image from NASA's Dawn spacecraft highlights Axomama Crater, the small crater shown to the right of center. It is 3 miles (5 kilometers) in diameter and located just inside the western rim of Dantu Crater. Axomama is one of the newly named craters on Ceres. Its sharp edges indicate recent emplacement by a small impact. This picture also shows details on the floor of Dantu, which comprises most of the image. The many fractures and the central pit (see also PIA20303) are reminiscent of Occator Crater and could point to a similar formation history, involving activity driven by the presence of liquid water in the subsurface. Axomama is named after the Incan goddess of potato, or "Potato-mother." NASA's Dawn spacecraft acquired this picture during its extended mission on July 24, 2016, from its low altitude mapping orbit at about 240 miles (385 kilometers) above the surface. The center coordinates of this image are 24 degrees north latitude, 131 degrees east longitude. https://photojournal.jpl.nasa.gov/catalog/PIA21908

Dawn HAMO Image 63

NASA Image and Video Library

2015-11-19

This image of Ceres from NASA's Dawn spacecraft shows hummocky terrain -- a surface covered in low, rounded hills -- with numerous impact craters of varying sizes. The two biggest craters display central peaks and many places where masses of material have collapsed and slid downward along their walls and floors -- a phenomenon geologists call "mass wasting". The sharp crater at upper right is surrounded by smooth ejecta with a streaky texture to the south. A graben -- what geologists call a linear feature where terrain has dropped -- measuring 2 to 5 miles (3 to 8 kilometers) in width, and two prominent scarps, or linear, cliff-like slopes, are located in the southeastern (lower right) part of the image. Dawn took this image on Oct. 5, 2015, from an altitude of 915 miles (1,470 kilometers). It has a resolution of 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA20125

Dawn XMO2 Image 24

NASA Image and Video Library

2016-12-13

This view from NASA's Dawn spacecraft shows part of the southwestern rim of Yalode Crater on Ceres. Yalode is one of the largest impact basins on Ceres, with a diameter of 160 miles (260 kilometers). The scene shows hummocky terrain where an impact formed a 14-mile (22-kilometer) wide crater with a central peak, seen at left. A great deal of material has slumped down the walls of the crater -- a phenomenon called mass wasting. The crater's impact ejecta forms a smooth blanket around its rim, which takes on a streaky texture leading away from the crater toward lower right. Dawn took this image on Oct. 22, 2016, from its second extended-mission science orbit (XMO2), at a distance of about 920 miles (1,480 kilometers) above the surface. The image resolution is about 460 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA21244

Topographic View of Ceres Mountain

NASA Image and Video Library

2015-09-30

This view, made using images taken by NASA's Dawn spacecraft, features a tall conical mountain on Ceres. Elevations span a range of about 5 miles (8 kilometers) from the lowest places in this region to the highest terrains. Blue represents the lowest elevation, and brown is the highest. The white streaks seen running down the side of the mountain are especially bright parts of the surface. The image was generated using two components: images of the surface taken during Dawn's High Altitude Mapping Orbit (HAMO) phase, where it viewed the surface at a resolution of about 450 feet (140 meters) per pixel, and a shape model generated using images taken at varying sun and viewing angles during Dawn's lower-resolution Survey phase. The image of the region is color-coded according to elevation, and then draped over the shape model to give this view. http://photojournal.jpl.nasa.gov/catalog/PIA19976

Mapping Vesta: First Results from Dawn's Survey Orbit

NASA Technical Reports Server (NTRS)

Jaumann, R.; Yingst, A. R.; Pieters, C. M.; Russell, C. T.; Raymond, C. A.; Neukum, G.; Mottola, S.; Keller, H. U.; Nathues, A.; Sierks, H.;

Soyuz TMA-03M Spacecraft prepares to dock with the MRM-1

NASA Image and Video Library

2011-12-23

ISS030-E-015605 (23 Dec. 2011) --- With the three Expedition 30/31 crew members aboard, the Soyuz TMA-03M spacecraft (left) eases toward its docking with the Russian-built Mini-Research Module 1 (MRM-1), also known as Rassvet, Russian for "dawn." The docking, which once more enables six astronauts and cosmonauts to work together aboard the Earth-orbiting International Space Station, took place at 9:19 a.m. (CST) on Dec. 23, 2011.

Soyuz TMA-03M Spacecraft prepares to dock with the MRM-1

NASA Image and Video Library

2011-12-23

ISS030-E-015603 (23 Dec. 2011) --- With the three Expedition 30/31 crew members aboard, the Soyuz TMA-03M spacecraft (left) eases toward its docking with the Russian-built Mini-Research Module 1 (MRM-1), also known as Rassvet, Russian for "dawn." The docking, which once more enables six astronauts and cosmonauts to work together aboard the Earth-orbiting International Space Station, took place at 9:19 a.m. (CST) on Dec. 23, 2011.

Soyuz TMA-03M Spacecraft prepares to dock with the MRM-1

NASA Image and Video Library

2011-12-23

ISS030-E-015599 (23 Dec. 2011) --- With the three Expedition 30/31 crew members aboard, the Soyuz TMA-03M spacecraft (left) eases toward its docking with the Russian-built Mini-Research Module 1 (MRM-1), also known as Rassvet, Russian for "dawn." The docking, which once more enables six astronauts and cosmonauts to work together aboard the Earth-orbiting International Space Station, took place at 9:19 a.m. (CST) on Dec. 23, 2011.

Saturnian Dawn

NASA Image and Video Library

2017-06-26

NASA's Cassini spacecraft peers toward a sliver of Saturn's sunlit atmosphere while the icy rings stretch across the foreground as a dark band. This view looks toward the unilluminated side of the rings from about 7 degrees below the ring plane. The image was taken in green light with the Cassini spacecraft wide-angle camera on March 31, 2017. The view was obtained at a distance of approximately 620,000 miles (1 million kilometers) from Saturn. Image scale is 38 miles (61 kilometers) per pixel. https://photojournal.jpl.nasa.gov/catalog/PIA21334

Hanami Planum on Ceres

NASA Image and Video Library

2018-03-22

This image from NASA's Dawn spacecraft showing the northern part of Hanami Planum on Ceres honors the Japanese cherry blossom festival, or "Hanami," which is a long-standing Japanese tradition of welcoming spring. Hanami Planum is the third largest geological feature on Ceres, after Vendimia Planitia and the Samhain Catenae. It extends over 345 miles (555 kilometers). This image shows familiar features, such as Occator Crater, characterized both by bright material inside the crater and dark ejecta material outside. Several parallel linear features, called Junina Catenae, can be seen departing from Occator and extending toward the top of the image. These catenae are chains of small craters formed by the impact and scouring of material ejected when large craters are formed. Scientists were able to relate these crater chains to Urvara and Yalode. Even though these are located in the southern hemisphere, some of their ejecta could reach the northern hemisphere, thanks to Ceres' fast rotation and small size. This image was obtained by Dawn on June 15, 2015. The spacecraft was then in its survey orbit (2,700 miles, or 4,400 kilometers high), when the footprint of Dawns framing camera on Ceres surface was about 260 miles (420 kilometers). The resolution is 1,400 feet (410 meters) per pixel. The central coordinates of the picture are 14 degrees north latitude, 213 degrees east in longitude. https://photojournal.jpl.nasa.gov/catalog/PIA21921

First observation of lion roar-like emissions in Saturn's magnetosheath

NASA Astrophysics Data System (ADS)

Pisa, David; Sulaiman, Ali H.; Santolik, Ondrej; Hospodarsky, George B.; Kurth, William S.; Gurnett, Donald A.

2017-04-01

Electromagnetic whistler mode waves known as "lion roars" have been reported by many missions inside the terrestrial magnetosheath. We show the observation of similar intense emissions in Saturn's magnetosheath as detected by the Cassini spacecraft. The emissions were observed inside the dawn sector (MLT˜0730) of the magnetosheath over a time period of nine hours before the satellite crossed the bow shock and entered the solar wind. The emissions were narrow-banded with a typical frequency of about 15 Hz well below the local electron cyclotron frequency (fce ˜100 Hz). Using the minimum variance analysis method, we show that the waves are right hand circularly polarized and propagate at small wave normal angles with respect to the ambient magnetic field. Here, for the first time, we report the evidence of lion roar-like emissions in Saturn's magnetosheath which represents a new and unique parameter regime.

Juling Crater

NASA Image and Video Library

2018-06-05

This image of Juling and Kupalo Craters was obtained by NASA's Dawn spacecraft on May 25, 2018 from an altitude of about 855 miles (1380 kilometers). The center coordinates of this image are about 38 degrees south in latitude and 173 degrees east in longitude. https://photojournal.jpl.nasa.gov/catalog/PIA22470

Ceres Sharper Than Ever Animation

NASA Image and Video Library

2015-01-27

This frame from an animation of the dwarf planet Ceres was made by combining images taken by the Dawn spacecraft on January 25, 2015. These images of Ceres, and they represent the highest-resolution views to date of the dwarf planet. http://photojournal.jpl.nasa.gov/catalog/PIA19171

Ceres RC3 Animation

NASA Image and Video Library

2015-05-11

In this closest-yet view of Ceres, the brightest spots within a crater in the northern hemisphere are revealed to be composed of many smaller spots. This frame is from an animation of sequences taken by NASA Dawn spacecraft on May 4, 2015. http://photojournal.jpl.nasa.gov/catalog/PIA19547

Anaglyph Image of the Mountain-Central Complex in Vesta South Polar Region

NASA Image and Video Library

2011-10-11

The broad morphology of asteroid Vesta mountain/central complex is clear in this image from NASA Dawn spacecraft; it is a roughly circular topographic mound, which is approximately 200km in diameter and has approximately 20km of relief from its base.

Vesta Surface in 3-D: A Big Mountain at the Asteroid South Pole

NASA Image and Video Library

2011-09-16

When NASA Dawn spacecraft sent the first images of the giant asteroid Vesta to the ground, scientists were fascinated by an enormous mound inside a big circular depression at the south pole. You need 3D glasses to view this image.

Dawn HAMO Image 60

NASA Image and Video Library

2015-11-16

Dantu crater on Ceres, seen here at left, reveals structures hinting at tectonic processes that formed the dwarf planet's surface. Linear structures are spread over the crater floor. Outside the crater's rim, the occurrence of linear structures continues the in form of scarps (linear, cliff-like slopes) and ridges. Dantu's diameter is 78 miles (125 kilometers). The image was taken by NASA's Dawn spacecraft on Oct. 3, 2015, from an altitude of 915 miles (1,470 kilometers). It has a resolution of 450 feet (140 meters) per pixel. The image is located at 31 degrees north latitude, 149 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA20122

Ernutet Crater - Enhanced Color

NASA Image and Video Library

2017-02-16

This enhanced color composite image, made with data from the framing camera aboard NASA's Dawn spacecraft, shows the area around Ernutet crater. The bright red portions appear redder with respect to the rest of Ceres. In a 2017 study in the journal Science, researchers from the Dawn science team found that these red areas around Ernutet are associated with evidence of organic material. Images taken using blue (440 nanometers), green (750 nanometers) and infrared (960 nanometers) spectral filters were combined to create the view. Ernutet Crater measures about 32 miles (52 kilometers) in diameter and is located in the northern hemisphere. http://photojournal.jpl.nasa.gov/catalog/PIA21419

Ceres Persistent Shadow

NASA Image and Video Library

2016-12-15

This frame from an animation made of images from NASA's Dawn spacecraft shows a crater in the northern polar region of Ceres that is partly in shadow year-round. In several craters like this one, bright water ice deposits have been observed by Dawn's framing camera. This finding suggests that water ice can be stored for significant amounts of time in cold, dark craters on Ceres. Such reservoirs are called "cold traps." At less than minus 260 degrees Fahrenheit (110 Kelvin), they are so chilly that very little of the ice turns into vapor in the course of a billion years. A movie is available at http://photojournal.jpl.nasa.gov/catalog/PIA21082

Zero to Integration in Eight Months, the Dawn Ground Data System Engineering Challenge

NASA Technical Reports Server (NTRS)

Dubon, Lydia P.

2006-01-01

The Dawn Project has presented the Ground Data System (GDS) with technical challenges driven by cost and schedule constraints commonly associated with National Aeronautics and Space Administration (NASA) Discovery Projects. The Dawn mission consists of a new and exciting Deep Space partnership among: the Jet Propulsion Laboratory (JPL), manages the project and is responsible for flight operation; Orbital Sciences Corporation (OSC), is the spacecraft builder and is responsible for flight system test and integration; and the University of California, at Los Angeles (UCLA), is responsible for science planning and operations. As a cost-capped mission, one of Dawn's implementation strategies is to leverage from both flight and ground heritage. OSC's ground data system is used for flight system test and integration as part of the flight heritage strategy. Mission operations, however, are to be conducted with JPL's ground system. The system engineering challenge of dealing with two heterogeneous ground systems emerged immediately. During the first technical interchange meeting between the JPL's GDS Team and OSC's Flight Software Team, August 2003, the need to integrate the ground system with the flight software was brought to the table. This need was driven by the project's commitment to enable instrument engineering model integration in a spacecraft simulator environment, for both demonstration and risk mitigation purposes, by April 2004. This paper will describe the system engineering approach that was undertaken by JPL's GDS Team in order to meet the technical challenge within a non-negotiable eight-month schedule. Key to the success was adherence to fundamental systems engineering practices: decomposition of the project request into manageable requirements; integration of multiple ground disciplines and experts into a focused team effort; definition of a structured yet flexible development process; definition of an in-process risk reduction plan; and aggregation of the intermediate products to an integrated final product. In addition, this paper will highlight the role of lessons learned from the integration experience. The lessons learned from an early GDS deployment have served as the foundation for the design and implementation of the Dawn Ground Data System.

Zero to Integration in Eight Months, the Dawn Ground Data System Engineering Challange

NASA Technical Reports Server (NTRS)

Dubon, Lydia P.

2006-01-01

The Dawn Project has presented the Ground Data System (GDS) with technical challenges driven by cost and schedule constraints commonly associated with National Aeronautics and Space Administration (NASA) Discovery Projects. The Dawn mission consists of a new and exciting Deep Space partnership among: the Jet Propulsion Laboratory (JPL), responsible for project management and flight operations; Orbital Sciences Corporation (OSC), spacecraft builder and responsible for flight system test and integration; and the University of California, at Los Angeles (UCLA), responsible for science planning and operations. As a cost-capped mission, one of Dawn s implementation strategies is to leverage from both flight and ground heritage. OSC's ground data system is used for flight system test and integration as part of the flight heritage strategy. Mission operations, however, are to be conducted with JPL s ground system. The system engineering challenge of dealing with two heterogeneous ground systems emerged immediately. During the first technical interchange meeting between the JPL s GDS Team and OSC's Flight Software Team, August 2003, the need to integrate the ground system with the flight software was brought to the table. This need was driven by the project s commitment to enable instrument engineering model integration in a spacecraft simulator environment, for both demonstration and risk mitigation purposes, by April 2004. This paper will describe the system engineering approach that was undertaken by JPL's GDS Team in order to meet the technical challenge within a non-negotiable eight-month schedule. Key to the success was adherence to an overall systems engineering process and fundamental systems engineering practices: decomposition of the project request into manageable requirements; definition of a structured yet flexible development process; integration of multiple ground disciplines and experts into a focused team effort; in-process risk management; and aggregation of the intermediate products to an integrated final product. In addition, this paper will highlight the role of lessons learned from the integration experience. The lessons learned from an early GDS deployment have served as the foundation for the design and implementation of the Dawn Ground Data System.

Vesta and the HED Meteorites: Comparison of Spectral Properties

NASA Technical Reports Server (NTRS)

Ammannito, E.; De Sanctis, M. C.; Fonte, S.; Magni, G.; Capaccioni, F.; Tosi, F.; Capria, M. T.; Blewett, D.; Combe, J. P.; Farina, M.;

A fully coupled flow simulation around spacecraft in low earth orbit

NASA Technical Reports Server (NTRS)

Justiz, C. R.; Sega, R. M.

1991-01-01

The primary objective of this investigation is to provide a full flow simulation of a spacecraft in low earth orbit (LEO). Due to the nature of the environment, the simulation includes the highly coupled effects of neutral particle flow, free stream plasma flow, nonequilibrium gas dynamics effects, spacecraft charging and electromagnetic field effects. Emphasis is placed on the near wake phenomenon and will be verified in space by the Wake Shield Facility (WSF) and developed for application to Space Station conditions as well as for other spacecraft. The WSF is a metallic disk-type structure that will provide a controlled space platform for highly accurate measurements. Preliminary results are presented for a full flow around a metallic disk.

Using Dawn to Observe SEP Events Past 2 AU

NASA Astrophysics Data System (ADS)

Villarreal, Michaela; Russell, Christopher T.; Prettyman, Thomas H.

2017-10-01

The launch of the STEREO spacecraft provided much insight into the longitudinal and radial distribution of solar energetic particles (SEPs) relative to their origin site. However, almost all of the observations of SEP events have been made exclusively near 1 AU. The Dawn mission, which orbited around Vesta before arriving at Ceres, provides an opportunity to analyze these events at much further distances. Although Dawn's Gamma Ray and Neutron Detector (GRaND) is not optimized for SEP characterization, it is sensitive to protons greater than 4 MeV, making it capable of detecting a solar energetic particle event in its vicinity. Solar energetic particles in this area of the solar system are important as they are believed to cause sputtering at bodies such as Ceres and comets (Villarreal et al., 2017; Wurz et al., 2015). In this study, we use Dawn’s GRaND data from 2011-2015 when Dawn was at distances between 2-3 AU. We compare the SEP events seen by Dawn with particle measurements at 1 AU using STEREO, Wind, and ACE to understand how the SEP events evolved past 1 AU.References: Villarreal, M. N., et al. (2017), The dependence of the Cerean exosphere on solar energetic particle events, Astrophys. J. Lett., 838, L8.Wurz, P. et al. (2015), Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko, A&A, 583, A22.

4 Vesta in Color: High Resolution Mapping from Dawn Framing Camera Images

NASA Technical Reports Server (NTRS)

Reddy, V.; LeCorre, L.; Nathues, A.; Sierks, H.; Christensen, U.; Hoffmann, M.; Schroeder, S. E.; Vincent, J. B.; McSween, H. Y.; Denevi, B. W.;

Dawn-dusk asymmetries in rotating magnetospheres: Lessons from modeling Saturn

NASA Astrophysics Data System (ADS)

Jia, Xianzhe; Kivelson, Margaret G.

2016-02-01

Spacecraft measurements reveal perplexing dawn-dusk asymmetries of field and plasma properties in the magnetospheres of Saturn and Jupiter. Here we describe a previously unrecognized source of dawn-dusk asymmetry in a rapidly rotating magnetosphere. We analyze two magnetohydrodynamic simulations, focusing on how flows along and across the field vary with local time in Saturn's dayside magnetosphere. As plasma rotates from dawn to noon on a dipolarizing flux tube, it flows away from the equator along the flux tube at roughly half of the sound speed (Cs), the maximum speed at which a bulk plasma can flow along a flux tube into a lower pressure region. As plasma rotates from noon to dusk on a stretching flux tube, the field-aligned component of its centripetal acceleration decreases and it flows back toward the equator at speeds typically smaller than 1/2 Cs. Correspondingly, the plasma sheet remains far thicker and the field less stretched in the afternoon than in the morning. Different radial force balance in the morning and afternoon sectors produce asymmetry in the plasma sheet thickness and a net dusk-to-dawn flow inside of L = 15 or equivalently, a large-scale electric field (E) oriented from postnoon to premidnight, as reported from observations. Morning-afternoon asymmetry analogous to that found at Saturn has been observed at Jupiter, and a noon-midnight component of E cannot be ruled out.

Statistical results from 10 years of Cassini Langmuir probe plasma measurements

NASA Astrophysics Data System (ADS)

Holmberg, M.; Shebanits, O.; Wahlund, J. E.; Morooka, M.; Andre, N.

2016-12-01

We use a new analysis method to obtain 10 years of Cassini RPWS Langmuir probe (LP) measurements to study the structure and dynamics of the inner plasma disk of Saturn. The LP plasma density measurements show good agreement with electron densities derived from the RPWS electric field power spectra and confirms and/or improves a number of previous findings about the structure of the plasma disk. E.g., the Enceladus plume is detected as a localised density maximum at the orbit of Enceladus, but the peak density of the inner plasma disk, excluding Enceladus plume passages, is located closer to 4.7 Rs. No density peaks are recorded at the orbits of the moons Mimas, Tethys, Dione, and Rhea. We confirm the previously detected plasma density dayside/nightside asymmetry, which is likely due to a particle drift in the dusk to dawn direction. Presented is also the LP result on the seasonal dependence of the plasma disk within Enceladus' orbit.

Reconciling the Dawn-Dusk Asymmetry in Mercury’s Exosphere with the Micrometeoroid Impact Directionality

NASA Astrophysics Data System (ADS)

Pokorný, Petr; Sarantos, Menelaos; Janches, Diego

2017-06-01

Combining dynamical models of dust from Jupiter-family comets and Halley-type comets, we demonstrate that the seasonal variation of the dust/meteoroid environment at Mercury is responsible for producing the dawn-dusk asymmetry in Mercury’s exosphere observed by the MESSENGER spacecraft. Our latest models, calibrated recently from ground-based and space-borne measurements, provide unprecedented statistics that enable us to study the longitudinal and latitudinal distribution of meteoroids impacting Mercury’s surface. We predict that the micrometeoroid impact vaporization source is expected to undergo significant motion on Mercury’s surface toward the nightside during Mercury’s approach to aphelion and toward the dayside when the planet is approaching the Sun.

Ionosphere of Venus - First observations of the dayside ion composition near dawn and dusk

NASA Technical Reports Server (NTRS)

Taylor, H. A., Jr.; Brinton, H. C.; Bauer, S. J.; Hartle, R. E.; Donahue, T. M.; Cloutier, P. A.; Michel, F. C.; Daniell, R. E., Jr.; Blackwell, B. H.

1979-01-01

Independent Bennett radio-frequency ion mass spectrometers on the Pioneer Venus bus and orbiter spacecraft obtained in situ measurements of the composition of the ionosphere of Venus. The spectrometer on the bus explored the dawn region while the spectrometer on the orbiter explored the duskside region. Information on the ion composition in the topside, the lower ionosphere, and the upper ionosphere is presented. Below the O(+) peak near 200 km, the ions are found to exhibit scale heights consistent with a neutral gas temperature of about 180 K near the terminator. In the upper ionosphere, scale heights of all species reflect the effects of plasma transport.

Reconciling the Dawn-Dusk Asymmetry in Mercury's Exosphere with the Micrometeoroid Impact Directionality

NASA Technical Reports Server (NTRS)

Pokorny, Petr; Sarantos, Menelaos; Janches, Diego

2017-01-01

Combining dynamical models of dust from Jupiter-family comets and Halley-type comets, we demonstrate that the seasonal variation of the dust/meteoroid environment at Mercury is responsible for producing the dawn-dusk asymmetry in Mercury's exosphere observed by the MESSENGER spacecraft. Our latest models, calibrated recently from ground-based and space-borne measurements, provide unprecedented statistics that enable us to study the longitudinal and latitudinal distribution of meteoroids impacting Mercury's surface. We predict that the micrometeoroid impact vaporization source is expected to undergo significant motion on Mercury's surface toward the nightside during Mercury's approach to aphelion and toward the dayside when the planet is approaching the Sun.

The Value of SysML Modeling During System Operations: A Case Study

NASA Technical Reports Server (NTRS)

Dutenhoffer, Chelsea; Tirona, Joseph

2013-01-01

System models are often touted as engineering tools that promote better understanding of systems, but these models are typically created during system design. The Ground Data System (GDS) team for the Dawn spacecraft took on a case study to see if benefits could be achieved by starting a model of a system already in operations. This paper focuses on the four steps the team undertook in modeling the Dawn GDS: defining a model structure, populating model elements, verifying that the model represented reality, and using the model to answer system-level questions and simplify day-to-day tasks. Throughout this paper the team outlines our thought processes and the system insights the model provided.

The value of SysML modeling during system operations: A case study

NASA Astrophysics Data System (ADS)

Dutenhoffer, C.; Tirona, J.

System models are often touted as engineering tools that promote better understanding of systems, but these models are typically created during system design. The Ground Data System (GDS) team for the Dawn spacecraft took on a case study to see if benefits could be achieved by starting a model of a system already in operations. This paper focuses on the four steps the team undertook in modeling the Dawn GDS: defining a model structure, populating model elements, verifying that the model represented reality, and using the model to answer system-level questions and simplify day-to-day tasks. Throughout this paper the team outlines our thought processes and the system insights the model provided.

Evidence for day-to-night ion transport at low solar activity in the Venus pre-dawn ionosphere

NASA Technical Reports Server (NTRS)

Brannon, J. F.; Fox, J. L.; Porter, H. S.

1993-01-01

Periapsis of the Pioneer Venus (PV) spacecraft dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would be necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

Evidence for Day-to-Night Ion Transport at Low Solar Activity in the Venus Pre-Dawn Ionosphere

NASA Technical Reports Server (NTRS)

Brannon, J. F.; Fox, J. L.; Porter, H. S.

1993-01-01

Periapsis of the Pioneer Venus spacecraft dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would be necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

Evidence for Day-to-Night Ion Transport at Low Solar Activity in the Venus Pre-Dawn Ionosphere

NASA Technical Reports Server (NTRS)

Brannon, J. F.; Fox, J. L.; Porter, H. S.

1993-01-01

Periapsis of the Pioneer Venus spacecraft 2 dropped below 180 km on August 28, 1992 near midnight, and 42 orbits of low altitude data at moderately low solar activity in the pre-dawn sector were obtained before contact was lost to the spacecraft in October, 1992. Through a combination of analysis of data from the PV orbiter ion mass spectrometer (OIMS) and modeling, we consider here what can be learned about the relative importance of plasma transport from the dayside and electron precipitation in maintaining the nightside ionosphere during the re-entry period. In particular, we examine here the atomic ion density profiles. We compute the average peak density of O(+) as a function of solar zenith angle and determine what fluxes of atomic ions or precipitating electrons would he necessary to produce those values. We then compare model calculations of the ion densities to those observed during the re-entry period. We find that the low solar activity nightside ionosphere shows evidence of significant day-to-night plasma transport.

Preliminary Assessment of New Orbital Debris Shielding for Unmanned Satellites

NASA Astrophysics Data System (ADS)

Wilkinson, J.; Stokes, H.; Walker, R.

The numerous rocket launches and spacecraft deployments carried out since the dawn of the space age have generated a large orbiting population of man-made debris. Without the adoption of mitigation measures, it is likely that this population will continue to increase in the future. The ever-growing collision threat posed to operating spacecraft from these debris objects is therefore fast becoming a driver in the design of new spacecraft missions. DERA, under contract from the European Space Agency (ESA), is developing new techniques to provide mass- and cost-effective solutions to this spacecraft protection problem. Direct shielding methods such as enhancing a spacecraft's thermal blankets with strong materials and adapting the honeycomb panel structure are being investigated, as are indirect shielding methods such as reconfiguration of critical or susceptible units. This paper reports the latest results of the direct shielding research.

Pre-Dawn Martian Sky

NASA Technical Reports Server (NTRS)

1997-01-01

On Sol 39 there were wispy blue clouds in the pre-dawn sky of Mars, as seen by the Imager for Mars Pathfinder (IMP). The color image was made by taking blue, green, and red images and then combining them into a single color image. The clouds appear to have a bluish side and a greenish side because they moved (in the wind from the northeast) between images. This picture was made an hour and twenty minutes before sunrise -- the sun is not shining directly on the water ice clouds, but they are illuminated by the dawn twilight.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Urvara and Yalode: Giant Craters on Ceres

NASA Image and Video Library

2018-02-22

This image from NASA's Dawn spacecraft shows the large craters Urvara (top) and Yalode (bottom) on dwarf planet Ceres. These features are so big that they must be observed from high altitudes in order to fit in the frame of a single image. Urvara is (101 miles (163 kilometers) in diameter, while Yalode is 162 miles (260 kilometers) in diameter. The two giant craters were formed at different times. Yalode is almost 1 billion years older than Urvara, which is about 120 million to 140 million years old. Yalode's relatively smooth floor indicates Ceres' crust material became close to -- or even reached -- the melting temperature of ice as a consequence of the heat generated by the impact. On the other hand, the smaller Urvara has rougher terrain. This suggests Urvara had either a lower temperature increase from the impact, or a colder crust temperature at the time of the crater's formation, or a combination of the two. Indeed, Ceres' interior was warmer in the past, and has been slowly cooling as its supply of radioactive isotopes, whose decay represents Ceres' main heat source, has been decreasing over time. This picture also reveals geological details such, as the feature Nar Sulcus inside Yalode and a central peak in Urvara. Urvara is named after the Indian and Iranian deity of plants and fields. Yalode is named for the Dahomey goddess, worshipped by women at the harvest rites. This image was obtained by NASA's Dawn spacecraft on June 9, 2015. The spacecraft was then in its survey orbit (2,700 miles, 4,400 kilometers above the surface), when the footprint of Dawn's framing camera on Ceres' surface was about 260 miles (420 kilometers) across on Ceres' surface. The resolution is 1,400 feet (410 meters) per pixel. The central coordinates of the picture are 43 degrees south latitude, 278 degrees east in longitude. https://photojournal.jpl.nasa.gov/catalog/PIA21917

Magnetotail Structure and its Internal Particle Dynamics During Northward IMF

NASA Technical Reports Server (NTRS)

Ashour-Abdalla, M.; Raeder, J.; El-Alaoui, M.; Peroomian, V.

1998-01-01

This study uses Global magnetohydrodynamic (MHD) simulations driven by solar wind data along with Geotail observations of the magnetotail to investigate the magnetotail's response to changes in the interplanetary magnetic field (IMF); observed events used in the study occurred on March 29, 1993 and February 9, 1995. For events from February 9, 1995, we also use the time-dependent MHD magnetic and electric fields and the large-scale kinetic (LSK) technique to examine changes in the Geotail ion velocity distributions. Our MHD simulation shows that on March 29, 1993, during a long period of steady northward IMF, the tail was strongly squeezed and twisted around the Sun-Earth axis in response to variations in the IMF B(sub y) component. The mixed (magnetotail and magnetosheath) plasma observed by Geotail results from the spacecraft's close proximity to the magnetopause and its frequent crossings of this boundary. In our second example (February 9, 1995) the IMF was also steady and northward, and in addition had a significant B(sub y) component. Again the magnetotail was twisted, but not as strongly as on March 29, 1993. The Geotail spacecraft, located approximately 30 R(sub E) downtail, observed highly structured ion distribution functions. Using the time-dependent LSK technique, we investigate the ion sources and acceleration mechanisms affecting the Geotail distribution functions during this interval. At 1325 UT most ions are found to enter the magnetosphere on the dusk side earthward of Geotail with a secondary source on the dawn side in the low latitude boundary layer (LLBL). A small percentage come from the ionosphere. By 1347 UT the majority of the ions come from the dawn side LLBL. The distribution functions measured during the later time interval are much warmer, mainly because particles reaching the spacecraft from the dawn side are affected by nonadiabatic scattering and acceleration in the neutral sheet.

Colors and Photometry of Bright Materials on Vesta as Seen by the Dawn Framing Camera

NASA Technical Reports Server (NTRS)

Schroeder, S. E.; Li, J.-Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.;

Dawn: Cooperation, not Control

NASA Technical Reports Server (NTRS)

May, Todd

2008-01-01

On September 27, 2007, a Delta II rocket carrying the Dawn spacecraft lifted off from Kennedy Space Center. Part of NASAs Discovery program, the $370 million Dawn mission began its three-billion-mile voyage to the asteroid belt to study the asteroid Vesta and Ceres, a dwarf planet. The spacecraft is scheduled to reach Vesta in 2011. After spending nine months measuring the composition, shape, and topography of that body, it will travel a billion miles to carry out a similar analysis of Ceres in 2015. The Important Lessons: The demands of Dawn and other challenging missions have taught some important lessons for successful program and project management. These are the main ones: a) Program management, particularly of uncoupled and loosely coupled projects, should be more about enabling than controlling. You're working with motivated, high-performing teams and institutions with a track record of quality and success. Emphasize commander's intent over rudder control; let them know where you want to go and when you want to be there, then let them figure out how to get there. b) Open and honest discussion of issues is essential. People fill the void of the unknown with their worst fears. Get folks around the table and have open, honest, and frank dialogue. I've seldom seen this fail to get to the root of issues. c) You have to earn your seat at the table, proving that you are competent, trustworthy, and dedicated to the success of the mission. d) Know when to fold 'em. Your pride can get rolled up in making a milestone or launch date, but you have to make a judgment based on the realities of the situation and not wear down the team trying to meet an increasingly impossible deadline. e) The NASA governance model that gives a voice to the concerns of engineers and safety experts works-trust it and use it.

Surface Mineralogy Mapping of Ceres from the Dawn Mission

NASA Astrophysics Data System (ADS)

McCord, T. B.; Zambon, F.

2017-12-01

Ceres' surface composition is of special interest because it is a window into the interior state and the past evolution of this dwarf planet. Disk-integrated telescopic spectral observations indicated that Ceres' surface is hydroxylated, similar to but not exactly the same as some of the carbonaceous chondrite classes of meteorites. Furthermore, Ceres' bulk density is low, indicating significant water content. The Dawn mission in orbit around Ceres, provided a new and larger set of observations on the mineralogy, molecular and elemental composition, and their distributions in association with surface features and geology. A set of articles was prepared, from which this presentation is derived, that is the first treatment of the entire surface composition of Ceres using the complete High Altitude Mapping Orbit (HAMO) Dawn Ceres data set and the calibrations from all the Dawn instruments. This report provides a current and comprehensive view of Ceres' surface composition and integrates them into general conclusions. Ceres' surface composition shows a fairly uniform distribution of NH4- and Mg-phyllosilicates, carbonates, mixed with a dark component. The widespread presence of phyllosilicates, and salts on Ceres' surface is indicative of the presence of aqueous alteration processes, which involved the whole dwarf planet. There is also likely some contamination by low velocity infall, as seen on Vesta, but it is more difficult to distinguish this infall from native Ceres material, unlike for the Vesta case.

Application of blind source separation to gamma ray spectra acquired by GRaND around Vesta

NASA Astrophysics Data System (ADS)

Mizzon, H.; Toplis, M. J.; Forni, O.; Prettyman, T. H.; Raymond, C. A.; Russell, C. T.

2012-12-01

The bismuth germinate (BGO) scintillator is one of the sensors of the gamma ray and neutron detector (GRaND)1 on board the Dawn spacecraft, that has spent just over one year in orbit around the asteroid 4-Vesta. The BGO detector is excited by energetic gamma-rays produced by galactic cosmic rays (GCR) or energetic solar particles interacting either with Vesta and/or the Dawn spacecraft. In detail, during periods of quiet solar activity, gamma ray spectra produced by the scintillator can be considered as consisting of three signals: i) a contribution of gamma-rays from Vesta produced by GCR interactions at the asteroid's surface, ii) a contribution from the spacecraft excited by neutrons coming from Vesta, and iii) a contribution of the spacecraft excited by local interaction with galactic cosmic rays. While the first two contributions should be positive functions of the solid angle of Vesta in the field of view during acquisition, the last one should have a negative dependence because Vesta partly shields the spacecraft from GCR. This theoretical mix can be written formally as: S=aΩSV+bΩSSCNV+c(4π-Ω)SSCGCR (1) where S is the series of recorded spectra, Ω is the solid angle, SV is the contribution of gamma rays coming from Vesta, SSCNV is the contribution of gamma rays coming from the spacecraft excited by the neutron coming from Vesta and SSCGCR is the contribution of gamma rays coming from the spacecraft excited by GCR. A blind source separation method called independent component analysis enables separating additive subcomponents supposing the mutual statistical independence of the non-Gaussian source signals2. Applying this method to BGO spectra acquired during the first three months of the low-altitude measurement orbit (LAMO) reveals two main independent components. The first one is dominated by the positron electron annihilation peak and is positively correlated to the solid angle. The second is negatively correlated to the solid angle and displays peaks of elements present in the spacecraft, of energy in the range 1 to 3.5 MeV. At energy >3.5 MeV, the dominant independent component highlighted by this method has no significant peaks, suggesting that it is not influenced by Vesta itself which is known to have a strong signal associated with iron at 7.6 MeV. Our method therefore represents a first step in retrieving the contribution of the spacecraft that could be used in conjunction with the mixing equation (1) to determine the contribution from the planet itself. 1 : Prettyman, T. H., Mcsween, Jr., H. Y., Feldman, W. C., JUN 2010. Dawn's GRaND to map the chemical composition of asteroids Vesta and Ceres. Geochimica and Cosmochimica Acta 74 (12, 1), A832, Con- ference on Goldschmidt 2010 - Earth, Energy, and the Environment, Knoxville, TN, JUN 13-18, 2010. 2 : Hyvarinen, A., Oja, E., May-Jun 2000. Independent component analysis: algorithms and applications. Neural Networks 13 (4-5), 411-430.

Ceres Evolution: From Thermodynamic Modeling and Now Dawn Observation

NASA Astrophysics Data System (ADS)

McCord, T. B.; Combe, J. P.; Castillo, J. C.; Raymond, C. A.; De Sanctis, M. C.; Jaumann, R.; Ammannito, E.; Russell, C. T.

2015-12-01

Thermodynamic modeling indicated that Ceres has experienced planetary processes, including extensive melting of its ~25% water and differentiation, (McCord and Sotin, JGR, 2005; Castillo and McCord, Icarus, 2009). Early telescopic studies showed Ceres' surface to be spectrally similar to carboneous-chondrite-like material, i.e., aqueously altered silicates darkened by carbon, with a water-OH-related absorption near 3.06 µm. Later observations improved the spectra and suggested more specific interpretations: Structural water in clay minerals, phyllosilicates, perhaps ammoniated, iron-rich clays, carbonates, brucite, all implying extensive aqueous alteration, perhaps in the presence of CO2. Telescopic observations and thermodynamic models predicted Dawn would find a very different body compared to Vesta (e.g. McCord et al., SSR, 2011), as current Dawn observations are confirming. Ceres' original water ice should have melted early in its evolution, with the resulting differentiation and mineralization strongly affecting Ceres' composition, size and shape over time. The ocean should have become very salty and perhaps may still be liquid in places. The surface composition from telescopes seems to reflect this complex history. The mineralization with repeated mixing of the crust with the early liquid interior and with in-fall from space would create a complex surface that will present an interpretation challenge for Dawn. The Dawn spacecraft is currently collecting observations of Ceres' landforms, elemental and mineralogical/molecular composition and gravity field from orbit. Early results suggest a heavily cratered but distorted and lumpy body with features and composition consistent with internal activity, perhaps recent or current, associated with water and perhaps other volatiles. We will present and interpret the latest Dawn Ceres findings and how they affect our earlier understanding of Ceres evolution from modeling and telescope observations.

KSC-07pd1598

NASA Image and Video Library

2007-06-20

KENNEDY SPACE CENTER, FLA. -- At Astrotech, the Dawn spacecraft is on display for a media showing. On each side are the folded solar array panels. The "box" in the upper center is the visual and infrared mapping spectrometer, which is designed to measure how much radiation of different "colors" is reflected or emitted by an object. At the bottom, under cover, is one of the ion propulsion thrusters. Dawn's goal is to characterize the conditions and processes of the solar system's earliest epoch by investigating in detail the largest protoplanets that have remained intact since their formations: asteroid Vesta and the dwarf planet Ceres. They reside in the extensive zone between Mars and Jupiter together with many other smaller bodies, called the asteroid belt. Photo credit: NASA/Kim Shiflett

Constraints on Vesta's elemental composition: Fast neutron measurements by Dawn's gamma ray and neutron detector

PubMed Central

Lawrence, David J; Peplowski, Patrick N; Prettyman, Thomas H; Feldman, William C; Bazell, David; Mittlefehldt, David W; Reedy, Robert C; Yamashita, Naoyuki

2013-01-01

Surface composition information from Vesta is reported using fast neutron data collected by the gamma ray and neutron detector on the Dawn spacecraft. After correcting for variations due to hydrogen, fast neutrons show a compositional dynamic range and spatial variability that is consistent with variations in average atomic mass from howardite, eucrite, and diogenite (HED) meteorites. These data provide additional compositional evidence that Vesta is the parent body to HED meteorites. A subset of fast neutron data having lower statistical precision show spatial variations that are consistent with a 400 ppm variability in hydrogen concentrations across Vesta and supports the idea that Vesta's hydrogen is due to long-term delivery of carbonaceous chondrite material. PMID:26074718

Spacecraft optical disk recorder memory buffer control

NASA Technical Reports Server (NTRS)

Hodson, Robert F.

1992-01-01

The goal of this project is to develop an Application Specific Integrated Circuit (ASIC) for use in the control electronics of the Spacecraft Optical Disk Recorder (SODR). Specifically, this project is to design an extendable memory buffer controller ASIC for rate matching between a system Input/Output port and the SODR's device interface. The aforementioned goal can be partitioned into the following sub-goals: (1) completion of ASIC design and simulation (on-going via ASEE fellowship); (2) ASIC Fabrication (at ASIC manufacturer); and (3) ASIC Testing (NASA/LaRC, Christopher Newport University).

First Complete Look at Ceres Poles

NASA Image and Video Library

2015-11-20

Researchers from NASA's Dawn mission have composed the first comprehensive views of the north (left) and south pole regions (right) of dwarf planet Ceres, using images obtained by the Dawn spacecraft. The images were taken between Aug. 17 and Oct. 23, 2015, from an altitude of 915 miles (1,470 kilometers). The region around the south pole appears black in this view because this area has been in shade ever since Dawn's arrival on March 6, 2015, and is therefore not visible. At the north polar region, craters Jarovit, Ghanan and Asari are visible, as well as the mountain Ysolo Mons. Near the south pole, craters Attis and Zadeni can be seen. Detailed maps of the polar regions allow researchers to study the craters in this area and compare them to those covering other parts of Ceres. Variations in shape and complexity can point to different surface compositions. In addition, the bottoms of some craters located close to the poles receive no sunlight throughout Ceres' orbit around the sun. Scientists want to investigate whether surface ice can be found there. http://photojournal.jpl.nasa.gov/catalog/PIA20126

Ceres' Global Cryosphere

NASA Astrophysics Data System (ADS)

Sizemore, H. G.; Prettyman, T. H.; De Sanctis, M. C.; Schmidt, B. E.; Hughson, K.; Chilton, H.; Castillo, J. C.; Platz, T.; Schorghofer, N.; Bland, M. T.; Sori, M.; Buczkowski, D.; Byrne, S.; Landis, M. E.; Fu, R.; Ermakov, A.; Raymond, C. A.; Schwartz, S. J.

2017-12-01

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to have a deep global cryosphere protected by a thin silicate lag. Gravity science along with data collected by Dawn's Framing Camera (FC), Gamma Ray and Neutron Detector (GRaND), and Visible and Infrared Mapping Spectrometer (VIR-MS) during the primary mission at Ceres have confirmed the existence of a global, silicate-rich cryosphere, and suggest the existence of deeper ice, brine, or mud layers. As such, Ceres' surface morphology has characteristics in common with both Mars and the small icy bodies of the outer solar system. We will summarize the evidence for the existence and global extent of the Cerean cryosphere. We will also discuss the range of morphological features that have been linked to subsurface ice, and highlight outstanding science questions.

Variations in the amount of water ice on Ceres' surface suggest a seasonal water cycle.

PubMed

Raponi, Andrea; De Sanctis, Maria Cristina; Frigeri, Alessandro; Ammannito, Eleonora; Ciarniello, Mauro; Formisano, Michelangelo; Combe, Jean-Philippe; Magni, Gianfranco; Tosi, Federico; Carrozzo, Filippo Giacomo; Fonte, Sergio; Giardino, Marco; Joy, Steven P; Polanskey, Carol A; Rayman, Marc D; Capaccioni, Fabrizio; Capria, Maria Teresa; Longobardo, Andrea; Palomba, Ernesto; Zambon, Francesca; Raymond, Carol A; Russell, Christopher T

2018-03-01

The dwarf planet Ceres is known to host a considerable amount of water in its interior, and areas of water ice were detected by the Dawn spacecraft on its surface. Moreover, sporadic water and hydroxyl emissions have been observed from space telescopes. We report the detection of water ice in a mid-latitude crater and its unexpected variation with time. The Dawn spectrometer data show a change of water ice signatures over a period of 6 months, which is well modeled as ~2-km 2 increase of water ice. The observed increase, coupled with Ceres' orbital parameters, points to an ongoing process that seems correlated with solar flux. The reported variation on Ceres' surface indicates that this body is chemically and physically active at the present time.

KSC-97PC1277

NASA Image and Video Library

1997-08-22

In the Payload Hazardous Servicing Facility (PHSF), Dan Maynard, a Jet Propulsion Laboratory technician, inserts the Digital Video Disk (DVD) into a shallow cavity between two pieces of aluminum that will protect it from micrometeoroid impacts. The package will be mounted to the side of the two-story-tall spacecraft beneath a pallet carrying cameras and other space instruments that will be used to study the Saturnian system. A specially designed, multicolored patch of thermal blanket material will be installed over the disk package. Along with the spacecraft, the disk will reside in Saturn's orbit centuries after the primary mission is completed in July 2008. The Cassini mission is managed for NASA's Office of Space Science, Washington, D.C., by the Jet Propulsion Laboratory, a division of the California Institute of Technology

Imaging Asteroid 4 Vesta Using the Framing Camera

NASA Technical Reports Server (NTRS)

Keller, H. Uwe; Nathues, Andreas; Coradini, Angioletta; Jaumann, Ralf; Jorda, Laurent; Li, Jian-Yang; Mittlefehldt, David W.; Mottola, Stefano; Raymond, C. A.; Schroeder, Stefan E.

2011-01-01

The Framing Camera (FC) onboard the Dawn spacecraft serves a dual purpose. Next to its central role as a prime science instrument it is also used for the complex navigation of the ion drive spacecraft. The CCD detector with 1024 by 1024 pixels provides the stability for a multiyear mission and its high requirements of photometric accuracy over the wavelength band from 400 to 1000 nm covered by 7 band-pass filters. Vesta will be observed from 3 orbit stages with image scales of 227, 63, and 17 m/px, respectively. The mapping of Vesta s surface with medium resolution will be only completed during the exit phase when the north pole will be illuminated. A detailed pointing strategy will cover the surface at least twice at similar phase angles to provide stereo views for reconstruction of the topography. During approach the phase function of Vesta was determined over a range of angles not accessible from earth. This is the first step in deriving the photometric function of the surface. Combining the topography based on stereo tie points with the photometry in an iterative procedure will disclose details of the surface morphology at considerably smaller scales than the pixel scale. The 7 color filters are well positioned to provide information on the spectral slope in the visible, the depth of the strong pyroxene absorption band, and their variability over the surface. Cross calibration with the VIR spectrometer that extends into the near IR will provide detailed maps of Vesta s surface mineralogy and physical properties. Georeferencing all these observation will result in a coherent and unique data set. During Dawn s approach and capture FC has already demonstrated its performance. The strong variation observed by the Hubble Space Telescope can now be correlated with surface units and features. We will report on results obtained from images taken during survey mode covering the whole illuminated surface. Vesta is a planet-like differentiated body, but its surface gravity and escape velocity are comparable to those of other asteroids and hence much smaller than those of the inner planets or

Photometric correction of VIR high space resolution data of Ceres

NASA Astrophysics Data System (ADS)

Longobardo, Andrea; Palomba, Ernesto; De Sanctis, Maria Cristina; Ciarniello, Mauro; Tosi, Federico; Giacomo Carrozzo, Filippo; Capria, Maria Teresa; Zambon, Francesca; Raponi, Andrea; Ammannito, Eleonora; Zinzi, Angelo; Raymond, Carol; Russell, Christopher T.; VIR-Dawn Team

2016-10-01

NASA's Dawn spacecraft [1] has been orbiting Ceres since early 2015. The mission is divided into five stages, characterized by different spacecraft altitudes corresponding to different space resolutions, i.e. Approach (CSA), Rotational Characterization (CSR), Survey (CSS), High Altitude Mapping Orbit (HAMO), and Low Altitude Mapping Orbit (LAMO).Ceres is a dark body (i.e. average albedo at 1.2 um is 0.08 [2]), hence photometric correction is much more important than for brighter asteroids (e.g. S-type and achondritric). Indeed, the negligible role of multiple scattering increases the reflectance dependence on phase angle.A photometric correction of VIR data at low spatial resolution (i.e. CSA, CSR, CSS) has already been applied with different methodologies (e.g. [2], [3]), These techniques highlight a reflectance and band depths dependency on the phase angle which is homogeneous on the entire surface in agreement with C-type taxonomy.However, with increasing spatial resolution (i.e. HAMO and LAMO data), the retrieval of a unique set of parameters for the photometric correction is no longer sufficient to obtain reliable albedo/band depth maps. In this work, a new photometric correction is obtained and applied to all the high resolution VIR data of Ceres, taking into account the reflectance variations observed at small scales. The developed algorithm will be implemented on the MATISSE tool [4] in order to be visualized on the Ceres shape model.Finally, an interpretation of the obtained phase functions is given in terms of optical and physical properties of the Ceres regolith.AcknowledgementsVIR was funded and coordinated by the Italian Space Agency, and built by SELEX ES, with the scientific leadership of IAPS-INAF, Rome, Italy, and is operated by IAPS-INAF, Rome, Italy. Support of the Dawn Science, Instrument, and Operation Teams is gratefully acknowledged.References[1] Russell, C. T. et al., 2012, Science 336, 686[2] Longobardo A., et al., 2016, LPSC, 2239[3] Ciarniello, M. et al., 2016, submitted to A&A[4] Zinzi, A. et al., 2016, A&C, 15, 16-28

KSC-05pd2539

NASA Image and Video Library

2005-12-01

KENNEDY SPACE CENTER, FLA. - Before dawn, the third stage, or upper stage for the New Horizons spacecraft, arrives at NASA Kennedy Space Center’s Payload Hazardous Servicing Facility. The third stage is a Boeing STAR 48 solid-propellant kick motor. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11 and fly through the Pluto system as early as summer 2015. New Horizons will be powered by a single radioisotope thermoelectric generator (RTG), provided by the Department of Energy, which will be installed shortly before launch.

Constraints on Ceres' Internal Structure and Evolution From Its Shape and Gravity Measured by the Dawn Spacecraft

NASA Astrophysics Data System (ADS)

Ermakov, A. I.; Fu, R. R.; Castillo-Rogez, J. C.; Raymond, C. A.; Park, R. S.; Preusker, F.; Russell, C. T.; Smith, D. E.; Zuber, M. T.

2017-11-01

Ceres is the largest body in the asteroid belt with a radius of approximately 470 km. In part due to its large mass, Ceres more closely approaches hydrostatic equilibrium than major asteroids. Pre-Dawn mission shape observations of Ceres revealed a shape consistent with a hydrostatic ellipsoid of revolution. The Dawn spacecraft Framing Camera has been imaging Ceres since March 2015, which has led to high-resolution shape models of the dwarf planet, while the gravity field has been globally determined to a spherical harmonic degree 14 (equivalent to a spatial wavelength of 211 km) and locally to 18 (a wavelength of 164 km). We use these shape and gravity models to constrain Ceres' internal structure. We find a negative correlation and admittance between topography and gravity at degree 2 and order 2. Low admittances between spherical harmonic degrees 3 and 16 are well explained by Airy isostatic compensation mechanism. Different models of isostasy give crustal densities between 1,200 and 1,400 kg/m3 with our preferred model giving a crustal density of 1,287+70-87 kg/m3. The mantle density is constrained to be 2,434+5-8 kg/m3. We compute isostatic gravity anomaly and find evidence for mascon-like structures in the two biggest basins. The topographic power spectrum of Ceres and its latitude dependence suggest that viscous relaxation occurred at the long wavelengths (>246 km). Our density constraints combined with finite element modeling of viscous relaxation suggests that the rheology and density of the shallow surface are most consistent with a rock, ice, salt and clathrate mixture.

Preliminary Geological Map of the Ac-H-8 Nawish Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

NASA Astrophysics Data System (ADS)

Frigeri, A.; De Sanctis, M. C.; Carrorro, F. G.; Ammannito, E.; Williams, D. A.; Mest, S. C.; Buczkowski, D.; Preusker, F.; Jaumann, R.; Roatsch, T.; Scully, J. E. C.; Raymond, C. A.; Russell, C. T.

2015-12-01

Herein we present the geologic mapping of the Ac-H-8 Nawish Quadrangle of dwarf planet Ceres, produced on the basis of the Dawn spacecraft data. The Ac-H-08 Nawish quadrangle is located between -22°S and 22°N and between 144°E and 216°E. At the north-east border, a polygonal, 75km-wide crater named Nawish gives the name to the whole quadrangle. An unamed, partially degraded, 100km-diameter crater is evident in the lower central sector of the quadrangle. Bright materials have been mapped and are associated with craters. For example, bright materials occur in the central peak region of Nawish crater and in the ejecta of an unnamed crater, which is located in the nearby quadrangle Ac-H-09. The topography of the area obtained from stereo-processing of imagery shows an highland in the middle of the quadrangle. Topography is lower in the northern and southern borders, with a altitude span of about 9500 meters. At the time of this writing geologic mapping was performed on Framing Camera (FC) mosaics from the Approach (1.3 km/px) and Survey (415 m/px) orbits, including grayscale and color images and digital terrain models derived from stereo images. In Fall 2015 images from the High Altitude Mapping Orbit (140 m/px) will be used to refine the mapping, followed by Low Altitude Mapping Orbit (35 m/px) images in January 2016. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA, and from the German and Italian Space Agencies.

Samhain Catenae on Ceres

NASA Image and Video Library

2017-11-09

This image made with data from NASA's Dawn spacecraft shows pit chains on dwarf planet Ceres called Samhain Catenae. Scientists created this image by draping the grayscale mosaic of Ceres' surface onto the shape model of the dwarf planet. The arrows in the image point to a few of the pit chains investigated in a 2017 study in the journal Geophysical Research Letters. https://photojournal.jpl.nasa.gov/catalog/PIA22086

Mineralogy of Inverted Pigeonite and Plagioclase in Cumulate Eucrites Y-980433 and Y-980318 with Reference to Early Crust Formation of the Vesta-Like Body

NASA Technical Reports Server (NTRS)

Takeda, H.; Ohtake, M.; Hiroi, T.; Nyquist, L. E.; Shih, C.-Y.; Yamaguchi, A.; Nagaoka, H.

2011-01-01

On July 16, the Dawn spacecraft became the first probe to enter orbit around asteroid 4 Vesta and will study the asteroid for a year before departing for Ceres. The Vesta-HED link is directly tied to the observed and inferred mineralogy of the asteroid and the mineralogy of the meteorites [1]. Pieters et al. [2] reported reflectance spectra of the Yamato- (Y-)980318 cumulate eucrite as a part of their study on the Asteroid-Meteorite Links in connection with the Dawn Mission. Pyroxenes and calcic plagioclase are the dominant minerals present in HED meteorites and provide multiple clues about how the parent body evolved [1]. The differentiation trends of HED meteorites are much simpler than those of the lunar crust

Kokopelli Crater on Ceres

NASA Image and Video Library

2017-12-14

This image obtained by NASA's Dawn spacecraft shows a field of small craters next to Kokopelli Crater, seen at bottom right in this image, on dwarf planet Ceres. The small craters overlay a smooth, wavy material that represents ejecta from nearby Dantu Crater. The small craters were formed by blocks ejected in the Dantu impact event, and likely from the Kokopelli impact as well. Kokopelli is named after the fertility deity who presides over agriculture in the tradition of the Pueblo people from the southwestern United States. The crater measures 21 miles (34 kilometers) in diameter. Dawn took this image during its first extended mission on August 11, 2016, from its low-altitude mapping orbit, at about 240 miles (385 kilometers) above the surface. The center coordinates of this image are 20 degrees north latitude, 123 degrees east longitude. https://photojournal.jpl.nasa.gov/catalog/PIA21915

'Rubber Duck' on Ceres

NASA Image and Video Library

2017-10-12

This image from NASA's Dawn spacecraft shows a group of craters, left of center, that resembles a rubber duck. Halki Crater, the "head," is 12 miles (20 kilometers) in diameter, while Telepinu Crater, the "body," is 19 miles (31 kilometers) across. They can be found in the global map of Ceres' names. The "beak" crater is unnamed. Halki and Telepinu have both been recently added to the list of official names for Ceres' geological features. They are both named after Hittite (Asia Minor) deities: the goddess of grain and the god of fertility and vegetation, respectively. Dawn acquired this picture on August 20, 2015, from its high-altitude mapping orbit at about 915 miles (1,470 kilometers) above the surface. The center coordinates of this image are 26 degrees north latitude, 339 degrees east longitude. https://photojournal.jpl.nasa.gov/catalog/PIA21909

New Views of Diverse Worlds

NASA Astrophysics Data System (ADS)

Blewett, D.

2012-08-01

Spacecraft exploration is in the process of revolutionizing our knowledge of the airless rocky bodies in the inner Solar System. Mercury has long been viewed as a planetary "end-member", but NASA's MESSENGER spacecraft, which flew past the innermost planet three times in 2008-09 and entered orbit in March of 2011, is finding that Mercury is even stranger than we thought. Mercury is weird in essentially all its characteristics: interior structure, surface composition, geology, topography, magnetic field, exosphere, and interaction with the space environment. Closer to home, a flotilla of international probes have targeted the Moon in the past few years. Giving lie to the "been there, done that" attitude held by many toward the Moon, the new missions are making many new discoveries and reminding us that there is much we don't know about our nearest planetary neighbor, and that rich opportunities for exploration are waiting nearby. Finally, I'll present findings from NASA's Dawn spacecraft, which will begin its orbital mission around the asteroid Vesta in mid-July 2011. Vesta is sometimes called "the smallest terrestrial planet" because it has separated into a crust, mantle, and core, and experienced a protracted geological evolution. Vesta is probably the source of a common class of meteorites, so we have abundant samples that help to inform our interpretation of the data to be obtained by Dawn. Mercury, the Moon, and Vesta are worlds who share some characteristics, but have taken radically different evolutionary paths. They provide insight into the most fundamental geological processes that likely affect all rocky planets - around our Sun or beyond.

Shadowed Craters on Ceres

NASA Image and Video Library

2016-07-08

At the poles of Ceres, scientists have found craters that are permanently in shadow (indicated by blue markings). Such craters are called "cold traps" if they remain below about minus 240 degrees Fahrenheit (minus 151 degrees Celsius). These shadowed craters may have been collecting ice for billions of years because they are so cold. This image was created using data from NASA's Dawn spacecraft. http://photojournal.jpl.nasa.gov/catalog/PIA20696

An Ion-Propelled Cubesat for Planetary Defense and Planetary Science

NASA Astrophysics Data System (ADS)

Russell, Christopher T.; Wirz, Richard; Lai, Hairong; Li, Jian-Yang; Connors, Martin

2017-04-01

Small satellites can reduce the cost of launch by riding along with other payloads on a large rocket or being launched on a small rocket, but are perceived as having limited capabilities. This perception can be at least partially overcome by innovative design, including ample in-flight propulsion. This allows achieving multiple targets and adaptive exploration. Ion propulsion has been pioneered on Deep Space 1 and honed on the long-duration, multiple-planetary body mission Dawn. Most importantly, the operation of such a mission is now well- understood, including navigation, communication, and science operations for remote sensing. We examined different mission concepts that can be used for both planetary defense and planetary science near 1 AU. Such a spacecraft would travel in the region between Venus and Mars, allowing a complete inventory of material above, including objects down to about 10m diameter to be inventoried. The ion engines could be used to approach these bodies slowly and carefully and allow the spacecraft to map debris and follow its collisional evolution throughout its orbit around the Sun, if so desired. The heritage of Dawn operations experience enables the mission to be operated inexpensively, and the engineering heritage will allow it to be operated for many trips around the Sun.

Dawnside Variability of Magnetic Field in High Latitude Regions of Saturn's Magnetosphere

NASA Astrophysics Data System (ADS)

Davies, E. H.; Masters, A.; Dougherty, M. K.; Sergis, N.

2017-12-01

Magnetic field lines at high latitudes in Saturn's post dawn sector tend to exhibit a swept-back configuration with respect to the direction of planetary rotation. This is a result of equatorial mass loading (mostly from the moon Enceladus) and the inability of planet to accelerate this plasma to co-rotation velocities, owing to plasma sinks in the system and the finite conductivity of the ionosphere. Results of a survey of high latitude magnetic field measurements within the dawn-noon sector from the Magnetometer Instrument (MAG) on the Cassini Spacecraft are presented. Data from 2004 to 2016 are used, representing almost the entire duration of the mission. 39 examples of field lines deviating in the direction of planetary rotation from their default configuration of sweep-back are found. These deviations represent the field sweeping forward towards a co-rotating (or occasionally super co-rotating) configuration, and occur transiently, on a timescale of hours. An analysis of these events, using data from the Magnetospheric Imaging Instrument (MIMI) is carried out. Several of the perturbed field events are found to correspond with the detection of high energy (on the order of 100 keV) electrons local to the spacecraft. It is suggested that these events are examples of return flow from magnetotail reconnection.

Dawn Color Topography of Ahuna Mons on Ceres

NASA Image and Video Library

2016-03-11

These color topographic views show variations in surface height around Ahuna Mons, a mysterious mountain on Ceres. The views are colorized versions of PIA20348 and PIA20349. They represent an update to the view in PIA19976, which showed the mountain using data from an earlier, higher orbit. Both views were made using images taken by NASA's Dawn spacecraft during its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) from the surface. The resolution of the component images is about 120 feet (35 meters) per pixel. Elevations span a range of about 5.5 miles (9 kilometers) from the lowest places in the region to the highest terrains. Blue represents the lowest elevation, and brown is the highest. The streaks running down the side of the mountain, which appear white in the grayscale view, are especially bright parts of the surface (the brightness does not relate to elevation). The elevations are from a shape model generated using images taken at varying sun and viewing angles during Dawn's lower-resolution, high-altitude mapping orbit (HAMO) phase. The side perspective view was generated by draping the image mosaics over the shape model. http://photojournal.jpl.nasa.gov/catalog/PIA20399

K/TH in Achondrites and Interpretation of Grand Data for the Dawn Mission

NASA Technical Reports Server (NTRS)

Usui, T.; McSween, H. Y., Jr.; Mittlefehldt, D. W.; Prettyman, T. H.

2008-01-01

The Dawn mission will explore 4 Vesta [1], a highly differentiated asteroid believed to be the parent body of the howardite, eucrite and diogenite (HED) meteorite suite [e.g. 2]. The Dawn spacecraft is equipped with a gamma-ray and neutron detector (GRaND), which will enable measurement and mapping of elemental abundances on Vesta s surface [3]. Drawing on HED geochemistry, Usui and McSween [4] proposed a linear mixing model for interpretation of GRaND data. However, the HED suite is not the only achondrite suite representing asteroidal basaltic crusts; others include the mesosiderites, angrites, NWA 011, and possibly Ibitira, each of which is thought to have a distinct parental asteroid [5]. Here we critically examine the variability of GRaND-analyzed elements, K and Th, in HED meteorites, and propose a method based on the K-Th systematics to distinguish between HED and the other differentiated achondrites. Maps of these elements might also recognize incompatible element enriched areas such as mapped locally on the Moon (KREEP) [6], and variations in K/Th ratios might indicate impact volatilization of K. We also propose a new mixing model using elements that will be most reliably measured by GRaND, including K.

Nature of the "Orange" Material on Vesta From Dawn

NASA Technical Reports Server (NTRS)

LeCorre, L.; Reddy, V.; Schmedemann, N.; Becker, K. J.; OBrien, D. P.; Yamashita, N.; Peplowski, P. N.; Prettyman, T. H.; Li, J.-Y.; Coultis, E. A.;

Colorimetric Solid Phase Extraction for the Measurement of Total I (Iodine, Iodide, and Triiodide) in Spacecraft Drinking Water

NASA Technical Reports Server (NTRS)

Lipert, Robert J.; Porter, Marc D.; Siperko, Lorraine M.; Gazda, Daniel B.; Rutz, Jeff A.; Schultz, John R.; Carrizales, Stephanie M.; McCoy, J. Torin

2009-01-01

An experimental drinking water monitoring kit for the measurement of iodine and silver(I) was recently delivered to the International Space Station (ISS). The kit is based on Colorimetric Solid Phase Extraction (CSPE) technology, which measures the change in diffuse reflectance of indicator disks following exposure to a water sample. To satisfy additional spacecraft water monitoring requirements, CSPE has now been extended to encompass the measurement of total I (iodine, iodide, and triiodide) through the introduction of an oxidizing agent, which converts iodide and triiodide to iodine, for measurement using the same indicator disks currently being tested on ISS. These disks detect iodine, but are insensitive to iodide and triiodide. We report here the operational considerations, design, and ground-based performance of the CSPE method for total I. The results demonstrate that CSPE technology is poised to meet NASA's total I monitoring requirements.

Ceres composition as inferred by the VIR-Dawn imaging spectrometer

NASA Astrophysics Data System (ADS)

Longobardo, Andrea

2016-07-01

The NASA's Dawn spacecraft [1] is orbiting around Ceres since early 2015. The Dawn mission to Ceres is divided in five stages, characterized by different altitudes above the Ceres mean surface. These five stages correspond with the different phases of the mission,, i.e. Approach, Rotational Characterization, Survey, High Altitude Mapping Orbit (HAMO) and Low Altitude Mapping Orbit (LAMO). Each phase is characterized by an increasing spatial resolution linked with the spacecraft altitude. The VIR imaging spectrometer [2] on board the Dawn spacecraft is providing a huge amount of data and giving an essential contribution to understand the Ceres composition and to give constraint about its evolution. VIR observations revealed that Ceres is a dark body, with an average albedo of 0.08 measured at 1.2 mm [3]. However, specific features seen at the local scale may show substantially higher albedo (i.e. greater than 0.2), especially in Occator, Haulani and Oxo craters [4]. VIR data reveal that the Ceres visible and near-infrared spectra (wavelength range from 0.25 to 5 mm) are mainly characterized by the following absorptions: - 2.7 mm band, ascribed to OH-bearing materials [5] and distributed across the Ceres surface; - 3.05 mm band, ascribed to NH4-bearing materials [5] and also ubiquitous on the Ceres surface; - 3.3-3.5 mm complex and 3.9 mm band, ascribed to carbonates [4] and observed only at some locations [6]. The presence of these features, in particular the 3.05 mm band, indicate widespread occurrence of ammoniated phyllosilicates [5], which could be mixed with carbonates in specific regions. The phyllosilicates composition is basically homogeneous across the Ceres surface, as suggested by the low variation of 2.7 mm and 3.05 mm band centers [7]. The presence of ammonia suggests the presence of outer Solar System materials, which could have been brought in the Main Asteroid Belt and accreted during the Ceres formation [8]. Alternatively, Ceres itself could have been formed in the outer Solar System before to migrate in its actual location [9]. References [1] Russell, C.T. et al., Science, 336, 684, 2012 [2] De Sanctis M.C. et al., Space Sci. Rev., 163, 329-336, 2011 [3] Longobardo, A. et al., LPSC abstract, #2239, 2016 [4] De Sanctis, M.C. et al., LPSC abstract, #1832, 2016 [5] De Sanctis, M.C. et al., Nature, 528, 241-244, 2015 [6] Palomba, E. et al., LPSC abstract, #2166, 2016 [7] Ammannito, E. et al., LPSC abstract, #3020, 2016 [8] Johansen, A. et al., Sci. Adv. 1, 1500109, 2015 [9] McKinnon, W.B. et al., Proc. Conf. Asteroids, Comets, Meteors, # 6475, 2012

Simulation and 'TWINS Observations of the 22 July 2009 Storm

NASA Technical Reports Server (NTRS)

Fok, Mei-Ching; Buzulukova, Natalia Y.; Chen, Sheng-Hsien; Valek, Phil; Goldstein, Jerry; McComas, David

2010-01-01

TWINS is the first mission to perform stereo imaging of the Earth's ring current. The magnetic storm on 22 July 2009 is the largest storm observed since TWINS began routine stereo imaging in June 2008. On 22 July 2009, the Dst dropped to nearly -80nT at 7:00 and 10:00 UT. During the main phase and at the peak of the storm, TWINS 1 and 2 were near apogee and moving from pre-dawn to post-dawn local time. The energetic neutral atom (ENA) imagers on the 2 spacecraft captured the storm intensification and the formation of the partial ring current. The peak of the ENA emissions was seen in the midnight-to-dawn local-time sector. The development of this storm has been simulated using the Comprehensive Ring Current Model (CRCM) to understand and interpret the observed signatures. We perform CRCM runs with constant and time-varying magnetic field. The model calculations are validated by comparing the simulated ENA and ion flux intensities with TWINS ENA images and in-situ ion data from THEMIS satellites. Simulation with static magnetic field produces a strong shielding electric field that skews the ion drift trajectories toward dawn. The model's corresponding peak ENA emissions are always eastward than those in the observed TWINS images. On the other hand, simulation with a dynamic magnetic field gives better spatial agreements with both ENA and insitu particle data, suggesting that temporal variations of the geomagnetic field exert a significant influence upon global ring current ion dynamics.

2001 Mars Odyssey THEMIS: Thermophysics at a New Local Time

NASA Astrophysics Data System (ADS)

Hamilton, V. E.; Christensen, P. R.

2017-12-01

During its sixth extended mission, the 2001 Mars Odyssey transitioned to a new, rarely-seen, post-sunset (morning daylight) local time designed to reduce stress on the spacecraft. Since then, Thermal Emission Imaging System (THEMIS) observations have provided an unprecedented opportunity to investigate dynamic phenomena in the atmosphere and on the surface. In this new local time ( 6:45 am/pm) orbit, Odyssey's camera is acquiring expanded diurnal thermal imaging coverage, providing insight into surface texture, layering, and ice content, as well as dynamic, temperature-dependent surface, atmospheric, and polar processes. New THEMIS observations at dawn and dusk local times are filling major gaps in current knowledge about the diurnal variation of clouds, hazes and surface frost. In this presentation, we will highlight some of these data and discuss the unique scientific results that can be obtained from Mars Odyssey THEMIS observations, including: insights into potential past and present habitability of Mars, the processes and history of climate, the nature and evolution of geologic processes, and aspects of the environment relevant to future human exploration.

Surface mapping via unsupervised classification of remote sensing: application to MESSENGER/MASCS and DAWN/VIRS data.

NASA Astrophysics Data System (ADS)

D'Amore, M.; Le Scaon, R.; Helbert, J.; Maturilli, A.

2017-12-01

Machine-learning achieved unprecedented results in high-dimensional data processing tasks with wide applications in various fields. Due to the growing number of complex nonlinear systems that have to be investigated in science and the bare raw size of data nowadays available, ML offers the unique ability to extract knowledge, regardless the specific application field. Examples are image segmentation, supervised/unsupervised/ semi-supervised classification, feature extraction, data dimensionality analysis/reduction.The MASCS instrument has mapped Mercury surface in the 400-1145 nm wavelength range during orbital observations by the MESSENGER spacecraft. We have conducted k-means unsupervised hierarchical clustering to identify and characterize spectral units from MASCS observations. The results display a dichotomy: a polar and equatorial units, possibly linked to compositional differences or weathering due to irradiation. To explore possible relations between composition and spectral behavior, we have compared the spectral provinces with elemental abundance maps derived from MESSENGER's X-Ray Spectrometer (XRS).For the Vesta application on DAWN Visible and infrared spectrometer (VIR) data, we explored several Machine Learning techniques: image segmentation method, stream algorithm and hierarchical clustering.The algorithm successfully separates the Olivine outcrops around two craters on Vesta's surface [1]. New maps summarizing the spectral and chemical signature of the surface could be automatically produced.We conclude that instead of hand digging in data, scientist could choose a subset of algorithms with well known feature (i.e. efficacy on the particular problem, speed, accuracy) and focus their effort in understanding what important characteristic of the groups found in the data mean. [1] E Ammannito et al. "Olivine in an unexpected location on Vesta's surface". In: Nature 504.7478 (2013), pp. 122-125.

KSC-06pd2268

NASA Image and Video Library

2006-10-11

KENNEDY SPACE CENTER, FLA. - Against a pre-dawn sky on Launch Pad 17-B at Cape Canaveral Air Force Station, the STEREO spacecraft is lifted up toward the platform on the mobile service tower. In the tower, STEREO will be mated with its launch vehicle, a Boeing Delta II rocket. STEREO stands for Solar Terrestrial Relations Observatory and comprises two spacecraft. The STEREO mission is the first to take measurements of the sun and solar wind in 3-dimension. This new view will improve our understanding of space weather and its impact on the Earth. The STEREO mission is managed by Goddard Space Flight Center. The Applied Physics Laboratory designed and built the spacecraft. The laboratory will maintain command and control of the observatories throughout the mission, while NASA tracks and receives the data, determines the orbit of the satellites, and coordinates the science results. STEREO is expected to lift off Oct. 25. Photo credit: NASA/George Shelton

KSC-06pd2267

NASA Image and Video Library

2006-10-11

KENNEDY SPACE CENTER, FLA. - Against a pre-dawn sky on Launch Pad 17-B at Cape Canaveral Air Force Station, the STEREO spacecraft is lifted alongside the mobile service tower. In the tower, STEREO will be mated with its launch vehicle, a Boeing Delta II rocket. STEREO stands for Solar Terrestrial Relations Observatory and comprises two spacecraft. The STEREO mission is the first to take measurements of the sun and solar wind in 3-dimension. This new view will improve our understanding of space weather and its impact on the Earth. The STEREO mission is managed by Goddard Space Flight Center. The Applied Physics Laboratory designed and built the spacecraft. The laboratory will maintain command and control of the observatories throughout the mission, while NASA tracks and receives the data, determines the orbit of the satellites, and coordinates the science results. STEREO is expected to lift off Oct. 25. Photo credit: NASA/George Shelton

Song trait similarity in great tits varies with social structure.

PubMed

Snijders, Lysanne; van der Eijk, Jerine; van Rooij, Erica P; de Goede, Piet; van Oers, Kees; Naguib, Marc

2015-01-01

For many animals, long-range signalling is essential to maintain contact with conspecifics. In territorial species, individuals often have to balance signalling towards unfamiliar potential competitors (to solely broadcast territory ownership) with signalling towards familiar immediate neighbours (to also maintain so-called "dear enemy" relations). Hence, to understand how signals evolve due to these multilevel relationships, it is important to understand how general signal traits vary in relation to the overall social environment. For many territorial songbirds dawn is a key signalling period, with several neighbouring individuals singing simultaneously without immediate conflict. In this study we tested whether sharing a territory boundary, rather than spatial proximity, is related to similarity in dawn song traits between territorial great tits (Parus major) in a wild personality-typed population. We collected a large dataset of automatized dawn song recordings from 72 unique male great tits, during the fertile period of their mate, and compared specific song traits between neighbours and non-neighbours. We show here that both song rate and start time of dawn song were repeatable song traits. Moreover, neighbours were significantly more dissimilar in song rate compared to non-neighbours, while there was no effect of proximity on song rate similarity. Additionally, similarity in start time of dawn song was unrelated to sharing a territory boundary, but birds were significantly more similar in start time of dawn song when they were breeding in close proximity of each other. We suggest that the dissimilarity in dawn song rate between neighbours is either the result of neighbouring great tits actively avoiding similar song rates to possibly prevent interference, or a passive consequence of territory settlement preferences relative to the types of neighbours. Neighbourhood structuring is therefore likely to be a relevant selection pressure shaping variation in territorial birdsong.

Development of a Star Tracker-Based Reference System for Accurate Attitude Determination of a Simulated Spacecraft

DTIC Science & Technology

2012-03-01

the mathematical pretext for quaternions, which summarizes as: In three- dimensional space , any displacement of a rigid body such that a ...for the patch board was selected, with a uniform 8 mm spacing between LED centers. Figure 33 is schematic of the patch board layout, and Fig. 34 shows...attitude determination since the dawn of the space age. Without accurate attitude determination, a “Lost- in-

Urvara Peaks

NASA Image and Video Library

2015-08-25

NASA's Dawn spacecraft took this image that shows a mountain ridge, near lower left, that lies in the center of Urvara crater on Ceres. Urvara is an Indian and Iranian deity of plants and fields. The crater's diameter is 101 miles (163 kilometers). This view was acquired on August 19, 2015, from a distance of 915 miles (1,470 kilometers). The resolution of the image is 450 feet (140 meters) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA19632

Emesh Crater on Ceres

NASA Image and Video Library

2017-11-02

This image taken by NASA's Dawn spacecraft shows Emesh, a crater on Ceres. Emesh, named after the Sumerian god of vegetation and agriculture, is 12 miles (20 kilometers) wide. Located at the edge of the Vendimia Planitia, the floor of this crater is asymmetrical with terraces distributed along the eastern rim. Additionally, this image shows many subtle linear features that are likely the surface expressions of faults. These faults play a big role in shaping Ceres' craters, leading to non-circular craters such as Emesh. To the left of Emesh in this view, a much older crater of similar size has mostly been erased by impacts and their ejecta. Dawn took this image on May 11, 2016, from its low-altitude mapping orbit, at a distance of about 240 miles (385 kilometers) above the surface. The center coordinates of this image are 11 degrees north latitude, 158 degrees east longitude. https://photojournal.jpl.nasa.gov/catalog/PIA21911

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

PubMed Central

Platz, T.; Schorghofer, N.; Prettyman, T. H.; De Sanctis, M. C.; Crown, D. A.; Schmedemann, N.; Neesemann, A.; Kneissl, T.; Marchi, S.; Schenk, P. M.; Bland, M. T.; Schmidt, B. E.; Hughson, K. H. G.; Tosi, F.; Zambon, F.; Mest, S. C.; Yingst, R. A.; Williams, D. A.; Russell, C. T.; Raymond, C. A.

2017-01-01

Abstract Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice‐rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization. PMID:28989206

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution.

PubMed

Sizemore, H G; Platz, T; Schorghofer, N; Prettyman, T H; De Sanctis, M C; Crown, D A; Schmedemann, N; Neesemann, A; Kneissl, T; Marchi, S; Schenk, P M; Bland, M T; Schmidt, B E; Hughson, K H G; Tosi, F; Zambon, F; Mest, S C; Yingst, R A; Williams, D A; Russell, C T; Raymond, C A

2017-07-16

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution

USGS Publications Warehouse

Sizemore, H.G.; Platz, Thomas; Schorghofer, Norbert; Prettyman, Thomas; De Sanctis, Maria Christina; Crown, David A.; Schmedemann, Nico; Nessemann, Andeas; Kneissl, Thomas; Simone Marchi,; Schenk, Paul M.; Bland, Michael T.; Schmidt, B.E.; Hughson, Kynan H.G.; Tosi, F.; Zambon, F; Mest, S.C.; Yingst, R.A.; Williams, D.A.; Russell, C.T.; Raymond, C.A.

2017-01-01

Prior to the arrival of the Dawn spacecraft at Ceres, the dwarf planet was anticipated to be ice-rich. Searches for morphological features related to ice have been ongoing during Dawn's mission at Ceres. Here we report the identification of pitted terrains associated with fresh Cerean impact craters. The Cerean pitted terrains exhibit strong morphological similarities to pitted materials previously identified on Mars (where ice is implicated in pit development) and Vesta (where the presence of ice is debated). We employ numerical models to investigate the formation of pitted materials on Ceres and discuss the relative importance of water ice and other volatiles in pit development there. We conclude that water ice likely plays an important role in pit development on Ceres. Similar pitted terrains may be common in the asteroid belt and may be of interest to future missions motivated by both astrobiology and in situ resource utilization.

Starting small: Revisiting young children's perceptions of social withdrawal in China.

PubMed

Ding, Xuechen; Coplan, Robert J; Sang, Biao; Liu, Junsheng; Pan, Tingting; Cheng, Chen

2015-06-01

In this reply to the commentaries by Xinyin Chen, Charissa Cheah, Yiyuan Xu, and Dawn Watling, we further discuss the conceptual and methodological challenges that arise when attempting to study beliefs about social withdrawal (1) in the unique cultural context of China and (2) in the unique developmental age period of early childhood. © 2015 The British Psychological Society.

A 29-year-old Harken disk mitral valve: long-term follow-up by echocardiographic and cineradiographic imaging.

PubMed

Hsi, David H; Ryan, Gerald F; Taft, Janice; Arnone, Thomas J

2003-01-01

An 81-year-old woman was evaluated for prosthetic mitral valve function. She had received a Harken disk mitral valve 29 years earlier due to severe mitral valve disease. This particular valve prosthesis is known for premature disk edge wear and erosion. The patients 2-dimensional Doppler echocardiogram showed the distinctive appearance of a disk mitral valve prosthesis. Color Doppler in diastole showed a unique crown appearance, with initial flow acceleration around the disk followed by convergence to laminar flow in the left ventricle. Cineradiographic imaging revealed normal valve function and minimal disk erosion. We believe this to be the longest reported follow-up of a surviving patient with a rare Harken disk valve. We present images with unique echocardiographic and cineangiographic features.

A 29-Year-Old Harken Disk Mitral Valve

PubMed Central

Hsi, David H.; Ryan, Gerald F.; Taft, Janice; Arnone, Thomas J.

2003-01-01

An 81-year-old woman was evaluated for prosthetic mitral valve function. She had received a Harken disk mitral valve 29 years earlier due to severe mitral valve disease. This particular valve prosthesis is known for premature disk edge wear and erosion. The patient's 2-dimensional Doppler echocardiogram showed the distinctive appearance of a disk mitral valve prosthesis. Color Doppler in diastole showed a unique crown appearance, with initial flow acceleration around the disk followed by convergence to laminar flow in the left ventricle. Cineradiographic imaging revealed normal valve function and minimal disk erosion. We believe this to be the longest reported follow-up of a surviving patient with a rare Harken disk valve. We present images with unique echocardiographic and cineangiographic features. (Tex Heart Inst J 2003;30:319–21) PMID:14677746

Earth - Full Disk View of Africa

NASA Image and Video Library

1996-01-29

This color image of the Earth was obtained by NASA Galileo spacecraft in Dec. 1990, when the spacecraft was about 1.5 million miles from the Earth. Africa stretches from the center to the top of the picture with the Arabian Peninsula off to its right. http://photojournal.jpl.nasa.gov/catalog/PIA00076

Moonshine: Diurnally varying hydration through natural distillation on the Moon, detected by the Lunar Exploration Neutron Detector (LEND).

PubMed

Livengood, T A; Chin, G; Sagdeev, R Z; Mitrofanov, I G; Boynton, W V; Evans, L G; Litvak, M L; McClanahan, T P; Sanin, A B; Starr, R D; Su, J J

2015-07-15

The Lunar Exploration Neutron Detector (LEND), on the polar-orbiting Lunar Reconnaissance Orbiter (LRO) spacecraft, has detected suppression in the Moon's naturally-occurring epithermal neutron leakage flux that is consistent with the presence of diurnally varying quantities of hydrogen in the regolith near the equator. Peak hydrogen concentration (neutron flux suppression) is on the dayside of the dawn terminator and diminishes through the dawn-to-noon sector. The minimum concentration of hydrogen is in the late afternoon and dusk sector. The chemical form of hydrogen is not determinable from these measurements, but other remote sensing methods and anticipated elemental availability suggest water molecules or hydroxyl ions. Signal-to-noise ratio at maximum contrast is 5.6 σ in each of two detector systems. Volatiles are deduced to collect in or on the cold nightside surface and distill out of the regolith after dawn as rotation exposes the surface to sunlight. Liberated volatiles migrate away from the warm subsolar region toward the nearby cold nightside surface beyond the terminator, resulting in maximum concentration at the dawn terminator. The peak concentration within the upper ~1 m of regolith is estimated to be 0.0125 ± 0.0022 weight-percent water-equivalent hydrogen (wt% WEH) at dawn, yielding an accumulation of 190 ± 30 ml recoverable water per square meter of regolith at each dawn. Volatile transport over the lunar surface in opposition to the Moon's rotation exposes molecules to solar ultraviolet radiation. The short lifetime against photolysis and permanent loss of hydrogen from the Moon requires a resupply rate that greatly exceeds anticipated delivery of hydrogen by solar wind implantation or by meteoroid impacts, suggesting that the surface inventory must be continually resupplied by release from a deep volatile inventory in the Moon. The natural distillation of water from the regolith by sunlight and its capture on the cold night surface may provide energy-efficient access to volatiles for in situ resource utilization (ISRU) by direct capture before volatiles can enter the surface, eliminating the need to actively mine regolith for volatile resource recovery.

Moonshine: Diurnally varying hydration through natural distillation on the Moon, detected by the Lunar Exploration Neutron Detector (LEND)

NASA Astrophysics Data System (ADS)

Livengood, T. A.; Chin, G.; Sagdeev, R. Z.; Mitrofanov, I. G.; Boynton, W. V.; Evans, L. G.; Litvak, M. L.; McClanahan, T. P.; Sanin, A. B.; Starr, R. D.; Su, J. J.

2015-07-01

The Lunar Exploration Neutron Detector (LEND), on the polar-orbiting Lunar Reconnaissance Orbiter (LRO) spacecraft, has detected suppression in the Moon's naturally-occurring epithermal neutron leakage flux that is consistent with the presence of diurnally varying quantities of hydrogen in the regolith near the equator. Peak hydrogen concentration (neutron flux suppression) is on the dayside of the dawn terminator and diminishes through the dawn-to-noon sector. The minimum concentration of hydrogen is in the late afternoon and dusk sector. The chemical form of hydrogen is not determinable from these measurements, but other remote sensing methods and anticipated elemental availability suggest water molecules or hydroxyl ions. Signal-to-noise ratio at maximum contrast is 5.6σ in each of two detector systems. Volatiles are deduced to collect in or on the cold nightside surface and distill out of the regolith after dawn as rotation exposes the surface to sunlight. Liberated volatiles migrate away from the warm subsolar region toward the nearby cold nightside surface beyond the terminator, resulting in maximum concentration at the dawn terminator. The peak concentration within the upper ∼1 m of regolith is estimated to be 0.0125 ± 0.0022 weight-percent water-equivalent hydrogen (wt% WEH) at dawn, yielding an accumulation of 190 ± 30 ml recoverable water per square meter of regolith at each dawn. Volatile transport over the lunar surface in opposition to the Moon's rotation exposes molecules to solar ultraviolet radiation. The short lifetime against photolysis and permanent loss of hydrogen from the Moon requires a resupply rate that greatly exceeds anticipated delivery of hydrogen by solar wind implantation or by meteoroid impacts, suggesting that the surface inventory must be continually resupplied by release from a deep volatile inventory in the Moon. The natural distillation of water from the regolith by sunlight and its capture on the cold night surface may provide energy-efficient access to volatiles for in situ resource utilization (ISRU) by direct capture before volatiles can enter the surface, eliminating the need to actively mine regolith for volatile resource recovery.

Moonshine: Diurnally varying hydration through natural distillation on the Moon, detected by the Lunar Exploration Neutron Detector (LEND)

PubMed Central

Livengood, T.A.; Chin, G.; Sagdeev, R.Z.; Mitrofanov, I.G.; Boynton, W.V.; Evans, L.G.; Litvak, M.L.; McClanahan, T.P.; Sanin, A.B.; Starr, R.D.; Su, J.J.

2016-01-01

The Lunar Exploration Neutron Detector (LEND), on the polar-orbiting Lunar Reconnaissance Orbiter (LRO) spacecraft, has detected suppression in the Moon’s naturally-occurring epithermal neutron leakage flux that is consistent with the presence of diurnally varying quantities of hydrogen in the regolith near the equator. Peak hydrogen concentration (neutron flux suppression) is on the dayside of the dawn terminator and diminishes through the dawn-to-noon sector. The minimum concentration of hydrogen is in the late afternoon and dusk sector. The chemical form of hydrogen is not determinable from these measurements, but other remote sensing methods and anticipated elemental availability suggest water molecules or hydroxyl ions. Signal-to-noise ratio at maximum contrast is 5.6σ in each of two detector systems. Volatiles are deduced to collect in or on the cold nightside surface and distill out of the regolith after dawn as rotation exposes the surface to sunlight. Liberated volatiles migrate away from the warm subsolar region toward the nearby cold nightside surface beyond the terminator, resulting in maximum concentration at the dawn terminator. The peak concentration within the upper ~1 m of regolith is estimated to be 0.0125 ± 0.0022 weight-percent water-equivalent hydrogen (wt% WEH) at dawn, yielding an accumulation of 190 ± 30 ml recoverable water per square meter of regolith at each dawn. Volatile transport over the lunar surface in opposition to the Moon’s rotation exposes molecules to solar ultraviolet radiation. The short lifetime against photolysis and permanent loss of hydrogen from the Moon requires a resupply rate that greatly exceeds anticipated delivery of hydrogen by solar wind implantation or by meteoroid impacts, suggesting that the surface inventory must be continually resupplied by release from a deep volatile inventory in the Moon. The natural distillation of water from the regolith by sunlight and its capture on the cold night surface may provide energy-efficient access to volatiles for in situ resource utilization (ISRU) by direct capture before volatiles can enter the surface, eliminating the need to actively mine regolith for volatile resource recovery. PMID:28798496

High-resolution Ceres HAMO Atlas derived from Dawn FC Images

NASA Astrophysics Data System (ADS)

Roatsch, T.; Kersten, E.; Matz, K. D.; Preusker, F.; Scholten, F.; Jaumann, R.; Raymond, C. A.; Russell, C. T.

2015-12-01

Introduction: NASA's Dawn spacecraft will orbit the dwarf planet Ceres in August and September 2015 in HAMO (High Altitude Mapping Orbit) with an altitude of about 1,500 km to characterize for instance the geology, topography, and shape of Ceres before it will be transferred to the lowest orbit. One of the major goals of this mission phase is the global mapping of Ceres. Data: The Dawn mission is equipped with a fram-ing camera (FC). The framing camera will take about 2600 clear filter images with a resolution of about 120 m/pixel and different viewing angles and different illumination conditions. Data Processing: The first step of the processing chain towards the cartographic products is to ortho-rectify the images to the proper scale and map projec-tion type. This process requires detailed information of the Dawn orbit and attitude data and of the topography of the target. Both, improved orientation and high-resolution shape models, are provided by stereo processing of the HAMO dataset. Ceres' HAMO shape model is used for the calculation of the ray intersection points while the map projection itself will be done onto a reference sphere for Ceres. The final step is the controlled mosaicking of all nadir images to a global mosaic of Ceres, the so called basemap. Ceres map tiles: The Ceres atlas will be produced in a scale of 1:750,000 and will consist of 15 tiles that conform to the quadrangle schema for small planets and medium size Icy satellites. A map scale of 1:750,000 guarantees a mapping at the highest availa-ble Dawn resolution in HAMO. Nomenclature: The Dawn team proposed to the International Astronomical Union (IAU) to use the names of gods and goddesses of agriculture and vege-tation from world mythology as names for the craters. This proposal was accepted by the IAU and the team proposed names for geological features to the IAU based on the HAMO mosaic. These feature names will be applied to the map tiles.

Automated Simulation For Analysis And Design

NASA Technical Reports Server (NTRS)

Cantwell, E.; Shenk, Tim; Robinson, Peter; Upadhye, R.

1992-01-01

Design Assistant Workstation (DAWN) software being developed to facilitate simulation of qualitative and quantitative aspects of behavior of life-support system in spacecraft, chemical-processing plant, heating and cooling system of large building, or any of variety of systems including interacting process streams and processes. Used to analyze alternative design scenarios or specific designs of such systems. Expert system will automate part of design analysis: reason independently by simulating design scenarios and return to designer with overall evaluations and recommendations.