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Kern, R. G.

Publications and source records attributed to Kern, R. G..

6 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Report of the Organic Contamination Science Steering Group

The exploration of the possible emergence and duration of life on Mars from landed platforms requires attention to the quality of measurements that address these objectives. In particular, the potential impact of terrestrial contamination on the measurement of reduced carbon with sensitive in situ instruments must be addressed in order to reach definitive conclusions regarding the source of organic molecules. Following the recommendation of the Mars Exploration Program Analysis Group (MEPAG) at its September 2003 meeting [MEPAG, 2003], the Mars Program Office at NASA Headquarters chartered the Organic Contamination Science Steering Group (OCSSG) to address this issue. The full report of the six week study of the OCSSG can be found on the MEPAG web site [1]. The study was intended to define the contamination problem and to begin to suggest solutions that could provide direction to the engineering teams that design and produce the Mars landed systems. Requirements set by the Planetary Protection Policy in effect for any specific mission do not directly address this question of the potential interference from terrestrial contaminants during in situ measurements.

Mahaffy, P. R.↗
NASA NTRS2003

Taguchi statistical design and analysis of cleaning methods for spacecraft materials

In this study, we have extensively tested various cleaning protocols. The variant parameters included the type and concentration of solvent, type of wipe, pretreatment conditions, and various rinsing systems. Taguchi statistical method was used to design and evaluate various cleaning conditions on ten common spacecraft materials.

Taguchi cleaning spacecraft materials↗
NASA NTRS2001

A comparison of mutations induced by accelerated iron particles versus those induced by low earth orbit space radiation in the FEM-3 gene of Caenorhabditis elegans

The fem-3 gene of Caenorhabditis elegans was employed to determine the mutation frequency as well as the nature of mutations induced by low earth orbit space radiation ambient to Space Shuttle flight STS-76. Recovered mutations were compared to those induced by accelerated iron ions generated by the AGS synchrotron accelerator at Brookhaven National Laboratory. For logistical reasons, dauer larvae were prepared at TCU, transported to either Kennedy Space Center or Brookhaven National Laboratory, flown in space or irradiated, returned to TCU and screened for mutants. A total of 25 fem-3 mutants were recovered after the shuttle flight and yielded a mutation frequency of 2.1x10(-5), roughly 3.3-fold higher than the spontaneous rate of 6.3x10(-6). Four of the mutations were homozygous inviable, suggesting that they were large deletions encompassing fem-3 as well as neighboring, essential genes. Southern blot analyses revealed that one of the 25 contained a polymorphism in fem-3, further evidence that space radiation can induce deletions. While no polymorphisms were detected among the iron ion-induced mutations, three of the 15 mutants were homozygous inviable, which is in keeping with previous observations that high LET iron particles generate deficiencies. These data provide evidence, albeit indirect, that an important mutagenic component of ambient space radiation is high LET charged particles such as iron ions.

short duration↗