SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The NASA Discovery STARDUST spacecraft is set to flyby the vicinity of the main belt asteroid Annefrank in November of this year on its way to encounter the comet P/Wild 2 in January 2004.
The NASA Discovery STARDUST spacecraft is set to flyby the vicinity of the main belt asteroid Annefrank in November of this year on its way to encounter the comet P/Wild 2 in January 2004.
Optical and radar observations reveal that 1999 GU3 is subkilometer-sized object with a synodic period of 9.0 days, low visual and radar albedos, and colors more consistent with the ordinarychondrites than the vast majority of main-belt asteroids.
In recent years, astronomers have focused their attention upon the near-Earth asteroids (NEAs), which are small (less than 10km), generally rocky solar-system bodies with orbits approaching Earth.
New observations show that reflectance colors of Earth-approaching asteroids depend on their sizes and orbits.
We describe Doppler-only radar observations of near-Earth asteroids 2062 Aten, 2101 Adonis, 3103 Eger, 4544 Xanthus, and 1992 QN that were obtained at Arecibo and Goldstone between 1984 and 1996. Estimates of the echo spectral bandwidths, radar cross sections, and circular polarization ratios of these objects constrain their pole-on breadths, radar albedos, surface roughnesses, taxonomic classes, rotation periods, and spin vectors.
The Terminal navigation of the NEAR spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts first to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde.
none given - From Synopsis & Objectives: JPL has analyzed and developed for SDIO a preliminary mission design for a deep space mission to flyby two near Earth asteroids, Eros and Toutatis.
This paper describes two aspects to the comet and asteroid hazard problem.
This paper describes several concepts for Near-Earth Asteroid sample return missions.
This paper will address the trajectory correction maneuvers (TCMs) which enabled the successful completion of the circuitous VEEGA trajectory while providing for the first ever encounters with main-belt asteroids.
The NASA Discovery Stardust spacecraft flew by the main belt asteroid 5535 Annefrank at a distance of 3100 km and a speed of 7.4 km/s in November 2002 to test the encounter sequence developed for its primary science target, the comet 81P/Wild2. During this testing, over 70 images of Annefrank were obtained, taken over a phase angle range from 40 to 140 degrees.
Jet Propulsion Laboratory's Near-Earth Asteroid Tracking (NEAT) program has two simultaneously-operating, autonomous search systems on two geographically-separated 1.2-m telescopes; one at the Maui Space Surveillance System (NEAT/MSSS) and the other on the Palomar Observatory's Oschin telescope (NEAT/Palomar). This paper will focus exclusively on the NEAT/MSSS system.
We develop a physical model of asteroid 1620 Geographos using Goldstone delay-Doppler radar images obtained Aug. 1994 (Ostro et al. 1996, Icarus 121, 46-66) with resolution as fine as 75 m, and optical lighcurves obtained in 1969, 1983, and 1993-94 (Magnusson et al. 1996, Icarus 123, 227-244).
We use a radar-derived physical model of 4179 Toutatis to investigate close-orbit dynamics around that irregularly shaped, non-principal-axis rotator. The orbital dynamics about this body are markedly different than the dynamics about uniformly rotating asteroids. The results of this paper have a wider application to orbit dynamics about bodies in a non-principal-axis rotation state.
NASA and Japan's Institute of Space and Astronautical Science (ISAS) have agreed to cooperate on the first mission to collect samples from the surface of an asteroid and return them to Earth for in-depth study.
We report initial results of daily delay/Doppler observations of Toutatis with the Goldstone 8510-MHz (3.5-cm) radar during November 25 - December 3, 1996. Using the physical model of Toutatis derived form 1992 radar observations (Hudson and Ostro 1995, Science 270, 84-86) to analyze the new data, we obtain refined estimates of the asteroid's orbit, spin state, and surface properties.
We have installed a large-format CCD camera on the 0.6 meter telescope at JPL's Table Mountain Observatory and used it to obtain high-accuracy astrometric obserations of asteroids and other solar system targets of interest.