A5000656680- Astro and Planetary Science
- Planetary Science and Exploration
- Spacecraft and Cryogenic Technologies
- Stellar, planetary, and galactic studies
- Spacecraft Design and Technology
- Space Science and Extraterrestrial Life
- Isotope Analysis in Ecology
- Astronomy and Astrophysical Research
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Space Exploration and Technology
- Atomic and Molecular Physics
- Geological and Geochemical Analysis
- Laser Design and Applications
- Space Satellite Systems and Control
- Historical Astronomy and Related Studies
- Gamma-ray bursts and supernovae
- Semiconductor Lasers and Optical Devices
- Nuclear Physics and Applications
- Space exploration and regulation
- Inertial Sensor and Navigation
- Solid State Laser Technologies
- Advanced Fiber Laser Technologies
- Marine and environmental studies
- Astronomical Observations and Instrumentation
Jet Propulsion Laboratory
2011-2025
California Institute of Technology
1988-2014
Joint Institute for Laboratory Astrophysics
1985-1989
National Institute of Standards and Technology
1984-1989
On 6 March 2015, Dawn arrived at Ceres to find a dark, desiccated surface punctuated by small, bright areas. Parts of Ceres’ are heavily cratered, but the largest expected craters absent. appears gravitationally relaxed only longest wavelengths, implying mechanically strong lithosphere with weaker deep interior. dry exterior displays hydroxylated silicates, including ammoniated clays endogenous origin. The possibility abundant volatiles depth is supported geomorphologic features such as flat...
The surface elemental composition of dwarf planet Ceres constrains its regolith ice content, aqueous alteration processes, and interior evolution. Using nuclear spectroscopy data acquired by NASA's Dawn mission, we determined the concentrations hydrogen, iron, potassium on Ceres. show that materials were processed action water within interior. non-icy portion Ceres' carbon-bearing contains similar amounts hydrogen to those present in aqueously altered carbonaceous chondrites; however,...
INTRODUCTION The surface of the dwarf planet Ceres is known to host phyllosilicate minerals, but their distribution and origin have not previously been determined. Phyllosilicates are hydrated silicates, presence on intriguing given that structure evolves through an aqueous alteration process. In addition, some phyllosilicates bear NH 4 , which places a constraint pH redox conditions during evolution Ceres. We studied across planet’s better understand evolutionary pathway RATIONALE Using...
The nucleus of the Jupiter-family comet 19P/Borrelly was closely observed by Miniature Integrated Camera and Spectrometer aboard Deep Space 1 spacecraft on 22 September 2001. 8-kilometer-long body is highly variegated a scale 200 meters, exhibiting large albedo variations (0.01 to 0.03) complex geologic relationships. Short-wavelength infrared spectra (1.3 2.6 micrometers) show slope toward red hot, dry surface (</=345 kelvin, with no trace water ice or hydrated minerals), consistent...
Covers advancements in spacecraft and tactical strategic missile systems, including subsystem design application, mission analysis, materials structures, developments space sciences, processing manufacturing, operations, applications of technologies to other fields.
Local detection of increasing amount water ice on Ceres’ surface indicates an active body and a possible seasonal cycle.
The Dawn mission, part of NASA's Discovery Program, has as its goal the scientific exploration two most massive main-belt asteroids, 4 Vesta, and dwarf planet 1 Ceres. spacecraft was launched from Cape Canaveral Air Force Station on September 27, 2007 a Delta-II 7925H-9.5 rocket that placed 1218-kg into an Earth-escape trajectory. On-board is ion propulsion system (IPS) developed at Jet Propulsion Laboratory which will provide additional delta- V approximately 11 km/s for heliocentric...
The Dawn mission has successfully completed operations at its first target, the main belt asteroid Vesta. quantity and quality of returned science data exceeded expectations, thus validating methodologies developed by project. Preparations are now underway for Dawn’s second orbital mission, this one with dwarf planet Ceres. Ceres will benefit from lessons learned Vesta operations, although planning execution be complicated absence two spacecraft reaction wheels, which was lost near end...
The Dawn mission orbited and explored Ceres Vesta, the two largest objects in main asteroid belt. One of key enabling technologies was solar electric propulsion. After more than 11 years flight, completed operations October 2018. I describe some lessons from perspective chief engineer manager/mission director.