NASA Scientific and Technical Aerospace Reports

iefly discussed with respect to impacts on makeup water storage (shipped tanks versus storage in prepackaged food). The
Dual Lander Transit Mission was selected for study because it has been considered by the Johnson Space Center Exploration
Office in enough detail to define a reasonable set of scenario options for nominal system operation and contingencies. This
study also illustrates the concept that there are multiple, reasonable life support system scenarios for any one particular
mission. Thus, the need for a particular commodity can depend upon many variables in the system. In this study, we examine
the need for makeup water as it depends upon the configuration of the rest of the life support system.
Author
Mars Landing Sites; Mars Missions; Food; Moisture Content; Life Support Systems
20040045264 NASA Ames Research Center, Moffett Field, CA, USA
Arc Jet Testing of Carbon Phenolic for Mars Sample Return and Future NASA Missions
Laub, Bernard; Chen, Yih-Kanq; Skokova, Kristina; Delano, Chad; January 2004; 22 pp.; In English; 55th Pacific Coast
Regional and Basic Science Division Fall Meeting, 19-22 Oct. 2003, Oakland, CA, USA; No Copyright; Avail: CASI; A03,
Hardcopy
The objective of the Mars Sample Return (MSR) Mission is to return a sample of MArtian soil to Earth. The Earth Entry
Vehicle (EEV) brings te samples through the atmosphere to the ground.The program aims to: Model aerothermal environment
during EEV flight; On the basis of results, select potential TPS materials for EEV forebody; Fabricate TPS materials; Test the
materials in the arc jet environment representative of predicted flight environment;Evaluate material performance; Compare
results of modeling predictions with test results.
Derived from text
Mars Sample Return Missions; Flight Characteristics; Spacecraft Reentry
20040045269 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
Space Weathering: An Ultraviolet Indicator
Hendrix, A. R.; Vilas, F.; [2004]; 2 pp.; In English
Contract(s)/Grant(s): NAG9-1209; No Copyright; Avail: CASI; A01, Hardcopy
We present evidence suggesting that the spectral slope of airless bodies in the UV-visible wavelength range can be used
as an indicator of exposure to space weathering. While space weathering generally produces a reddening of spectra in the
visible-NIR spectral regions, it tends to result in a bluing of the UV-visible portion of the spectrum, and may in some cases
produce a spectral reversal. The bluing effect may be detectable with smaller amounts of weathering than are necessary to
detect the longer-wavelength weathering effects.
Author
Space Weathering; Ultraviolet Radiation; Light (Visible Radiation); Lunar Exploration
20040045270 Jet Propulsion Lab., California Inst. of Tech., Pasadena, CA, USA
Vesta’s UV Lightcurve: Hemispheric Variation in Brightness and Spectral Reversal
Hendrix, Amanda R.; Vilas, Faith; Festou, Michael; Icarus; 2003; ISSN 0019-1035; Volume 162, pp. 1-9; In English
Contract(s)/Grant(s): NAG9-1209; Copyright; Avail: Other Sources
Spectra of asteroid 4 Vesta obtained in October 1990 with the International Ultraviolet Explorer are reanalyzed and
reinterpreted. A large portion of the eastern hemisphere (based on the prime meridian definition of Thomas et al., 1997a) is
darker at UV Wavelengths than much of the western hemisphere. The UV lightcurve is in contrast with the visible lightcurve,
which shows that the eastern hemisphere is brighter than the western. These IUE spectra of Vesta thus may be evidence for
the ’spectral reversal.‘ first seen on the Moon by Apollo 17. where the visibly brighter lunar highlands are darker than the maria
at far-UV wavelengths. This effect was linked to space weathering when it was noted (Wagner et al., 1987) that the spectral
reversal appears in the laboratory spectra of lunar soils but not powdered lunar rocks. We investigate Vesta’s UV lightcurve
and spectral reversal, and its possible connection with space weathering. The addition to grain coatings of small amounts of
submicroscopic iron (SMFe) through vapor deposition causes drastic spectral changes at UV-visible wavelengths (Hapke,
2001). while the longer wavelength spectrum remains largely unaffected. Other laboratory results (e.g., Hiroi and Pieters,
1998) indicate that the UV-visible wavelength range is affected by simulated weathering processes in a manner similar to what
is seen on Vesta. It is likely that Vesta has experienced relatively minor amounts of space weathering, as indicated by the
spectral reversal, along with the subtle visible-near infrared weathering effects (e.g., Binzel et al., 1997).
Author
Brightness; Eastern Hemisphere; Light Curve; Ultraviolet Spectra; Vesta Asteroid
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