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Hicks, M. D.

Publications and source records attributed to Hicks, M. D..

17 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

A Wavelength-Dependent Visible and Infrared Spectrophotometric Function for the Moon based on ROLO Data

The USGS's Robotic Lunar Observatory (ROLO) dedicated ground-based lunar calibration project obtained photometric observations of the Moon over the spectral range attainable from Earth (0.347-2.39 microns) and over solar phase angles of 1.55 deg -97 deg . From these observations, we derived empirical lunar surface solar phase functions for both the highlands and maria that can be used for a wide range of applications. The functions can be used to correct for the effects of viewing geometry to produce lunar mosaics, spectra, and quick-look products for future lunar missions and ground-based observations. Our methodology can be used for a wide range of objects for which multiply scattered radiation is not significant, including all but the very brightest asteroids and moons.

Planetary Sciences↗
NASA NTRS2003

Recent discoveries and advances for the Near-Earth Asteroid Tracking program with MSSS 1.2-meter telescope

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.

NEO near earth objects NEAT Near-Earth Asteroid Tr↗
NASA NTRS2002

An update of the Near-Earth Asteroid Tracking/Maui Space Surveillance System (NEAT/MSSS) collaboration

Jet Propulsion Laboratory's (JPL) 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.

NEAT MSSS↗
NASA NTRS2002

Hyperion's Dark Material: Rotational Variation

We present two new dark material spectra of Hyperion compared with previously published dark material spectra of Hyperion and Iapetus. A 0.67-micron absorption feature is seen in one of the two new spectra. This suggests possible mineralogical differences across the surface of this Saturnian satellite. Additional information is contained in the original extended abstract.

Jarvis, K. S.↗
NASA NTRS2002

The Geology of Comet 19/P Borrelly

The Deep Space One spacecraft flew by Comet 19P/Borrelly on September 22, 2001 and returned a rich array of imagery with resolutions of up to 48 m/pixel. These images provide a window into the surface structure, processes, and geological history of a comet. Additional information is contained in the original extended abstract.

Britt, D. T.↗
NASA NTRS2002

Photometric Modeling of a Cometary Nucleus: Taking Hapke Modeling to the Limit

In the past two decades, photometric models developed by Bruce Hapke have been fit to a wide range of bodies in the Solar System: The Moon, Mercury, several asteroids, and many icy and rocky satellites. These models have enabled comparative descriptions of the physical attributes of planetary surfaces, including macroscopic roughness, particle size and size-distribution, the single scattering albedo, and the compaction state of the optically active portion of the regolith. One challenging type of body to observe and model, a cometary nucleus, awaited the first space based mission to obtain images unobscured by coma. The NASA-JPL Deep Space 1 Mission (DS1) encountered the short-period Jupiter-family comet 19/P Borrelly on September 22, 2001, about 8 days after perihelion. Prior to its closest approach of 2171 km, the remote-sensing package on the spacecraft obtained 25 CCD images of the comet, representing the first closeup, unobscured view of a comet's nucleus. At closest approach, corresponding to a resolution of 47 meters per pixel, the intensity of the coma was less than 1% of that of the nucleus. An unprecedented range of high solar phase angles (52-89 degrees), viewing geometries that are in general attainable only when a comet is active, enabled the first quantitative and disk-resolved modeling of surface photometric physical parameters.

Buratti, B. J.↗
NASA NTRS2002

Deep Space 1 photometry of the nucleus of Comet P/19 Borrelly

The NASA-JPL Deep Space 1 Mission (DS1) encountered the short-period Jupiter-family comet 19/P Borrelly on September 22, 2001, about 8 days after perihelion. DS1's payload contained a remote-sensing package that included a 1024 square CCD and a near IR spectrometer with ~12nm resolution. Prior to its closest approach, the remote-sensing package on the spacecraft obtained 25 CCD images of the comet and 45 near-IR spectra.

Deep Space 1 comets photometry↗
NASA NTRS2000

Slowly rotating asteroid 1999 GU/sub 3

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.

asteroids rotation photometry radar↗
NASA NTRS1998

Triton Blushes: A Clue to Global Warming?

The large Neptunian satellite Triton is a geologically active body that apparently undergoes complex seasonal changes in its 165 year journey around the sun. Because it is the vehicle for the seasonal transport of volatiles, Triton's atmosphere is expected to undergo large changes in temperature and pressure on a time scale of decades.

Triton Neptune Global Warming↗
NASA NTRS1990

Quantitative computer representation of propellant processing

With the technology currently available for the manufacture of propellants, it is possible to control the variance of the total specific impulse obtained from the rocket boosters to within approximately five percent. Though at first inspection this may appear to be a reasonable amount of control, when it is considered that any uncertainty in the total kinetic energy delivered to the spacecraft translates into a design with less total usable payload, even this degree of uncertainty becomes unacceptable. There is strong motivation to control the variance in the specific impulse of the shuttle's solid boosters. Any small gains in the predictability and reliability of the booster would lead to a very substantial payoff in earth-to-orbit payload. The purpose of this study is to examine one aspect of the manufacture of solid propellants, namely, the mixing process. The traditional approach of computational fluid mechanics is notoriously complex and time consuming. Certain simplifications are made, yet certain fundamental aspects of the mixing process are investigated as a whole. It is possible to consider a mixing process in a mathematical sense as an operator, F, which maps a domain back upon itself. An operator which demonstrates good mixing should be able to spread any subset of the domain completely and evenly throughout the whole domain by successive applications of the mixing operator, F. Two and three dimensional models are developed and graphical visualization two and three dimensional mixing processes are presented.

Hicks, M. D.↗