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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.
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We have developed methods of inversion that can be used in the determination of the three-dimensional shape or the albedo distribution of the surface of a body from disk-integrated photometry, assuming the shape to be strictly convex. In addition to the theory of inversion methods, we have studied the practical aspects of the inversion problem and applied our methods to lightcurve data of 39 Laetitia and 16 Psyche.
Jet Propulsion Laboratory initiatives in developing and formulating planetary CubeSats are described. Six flight systems already complete or underway now at JPL for missions to interplanetary space, the Moon, a near-Earth asteroid, and Mars are described at the subsystem level. Key differences between interplanetary nanospacecraft and LEO CubeSats are explained, as well as JPL's adaptation of vendor components and development of system solutions to meet planetary-mission needs. Feasible technology-demonstration and science measurement objectives are described for multiple modes of planetary mission implementation. Seven planetary-science demonstration mission concepts, already proposed to NASA by Discovery-2014 PIs partnered with JPL, are described for investigations at Sun-Earth L5, Venus, NEA 1999 FG3, comet Tempel 2, Phobos, main-belt asteroid 24 Themis, and metal asteroid 16 Psyche. The JPL staff and facilities resources available to PIs for analysis, design, and development of planetary nanospacecraft are catalogued.
Recent upgrades to the performance capabilities of the NASA Ames Vertical Gun Range(AVGR) are presented. Upgrades include: the successful implementation of a fast-acting, gun gases suppression valve to minimize target contamination and perturbations to both the target and ejecta; powder gun and light-gas gun operational parameter adjustments to provide clean, low speed test conditions; a liquid nitrogen-based system and methodology for chilling targets and/or other impact chamber situated equipment; and imaging system capabilities enhancements to enable observing 50 micrometer particles traveling at 2 km/s. Many of these performance improvements were motivated by AVGR customer requirements for very clean shot conditions at speeds below 1.9 km/s and to provide testing in support of proposed NASA missions to Enceladus and 16-Psyche.
A compact, low-mass light shield has been designed for the Psyche space mission high-purity germanium gamma-ray spectrometer. The spectrometer will be vented to space, which can allow solar photons to enter the cryostat and cause charge-induced noise. The light shield was designed to block more than 99.9% of solar photons while maintaining high molecular conductance to space vacuum. COMSOL simulations and experiments were performed to characterize light shield photon attenuation and molecular conductance. Finally, the light shield was integrated onto the gamma-ray spectrometer and photon suppression and vacuum performance were demonstrated.