NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Biological Sterilization of Returned Mars SamplesMartian rock and soil, collected by robotic spacecraft, will be returned to terrestrial laboratories early in the next century. Current plans call for the samples to be immediately placed into biological containment and tested for signs of present or past life and biological hazards. It is recommended that "Controlled distribution of unsterilized materials from Mars should occur only if rigorous analyses determine that the materials do not constitute a biological hazard. If any portion of the sample is removed from containment prior to completion of these analyses it should first be sterilized." While sterilization of Mars samples may not be required, an acceptable method must be available before the samples are returned to Earth. The sterilization method should be capable of destroying a wide range of organisms with minimal effects on the geologic samples. A variety of biological sterilization techniques and materials are currently in use, including dry heat, high pressure steam, gases, plasmas and ionizing radiation. Gamma radiation is routinely used to inactivate viruses and destroy bacteria in medical research. Many commercial sterilizers use Co-60 , which emits gamma photons of 1.17 and 1.33 MeV. Absorbed doses of approximately 1 Mrad (10(exp 8) ergs/g) destroy most bacteria. This study investigates the effects of lethal doses of Co-60 gamma radiation on materials similar to those anticipated to be returned from Mars. The goals are to determine the gamma dose required to kill microorganisms in rock and soil samples and to determine the effects of gamma sterilization on the samples' isotopic, chemical and physical properties. Additional information is contained in the original extended abstract.
Document ID
20000110272
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Allen, C. C.
(Lockheed Martin Space Operations Houston, TX United States)
Albert, F. G.
(Montana Biotech Corp. Belgrade, MT United States)
Combie, J.
(Montana Biotech Corp. Belgrade, MT United States)
Bodnar, R. J.
(Virginia Tech. Blacksburg, VA United States)
Hamilton, V. E.
(Arizona State Univ. Tempe, AZ United States)
Jolliff, B. L.
(Washington Univ. Saint Louis, MO United States)
Kuebler, K.
(Washington Univ. Saint Louis, MO United States)
Wang, A.
(Washington Univ. Saint Louis, MO United States)
Lindstrom, D. J.
(NASA Johnson Space Center Houston, TX United States)
Morris, P. A.
(Houston Univ. TX United States)
Date Acquired
August 19, 2013
Publication Date
July 1, 1999
Publication Information
Publication: The Fifth International Conference on Mars
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available