Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-06T07:17:43.991Z Has data issue: false hasContentIssue false

The effect of spacecraft descent engine plumes on spore transfer to planetary surfaces: Phoenix as a test case

Published online by Cambridge University Press:  03 June 2011

J.R. Marshall
Affiliation:
SETI Institute, 189 North Bernardo Avenue, Mountain View, CA 94043, USA

Abstract

Laboratory experiments were conducted to determine the effect of descent-engine plumes on the scouring of surface (microbial) contaminants from a spacecraft. A simulated touchdown of a half-scale lander engine and deck configuration was conducted at Mars atmospheric pressure in the NASA Ames Planetary Aeolian Laboratory. Low-density particles were used for the soil simulant to emulate the lower Martian gravity. The underside of the model had small witness plates with controlled microbial surface populations and particle impact detectors. For both steady-state engine thrust (Viking) and pulsed engine thrust (Phoenix), the exhaust plumes from the engines violently excavated the soil and produced particle-laden eddies beneath the lander that sandblasted the lander underside. The result was nearly complete erosion of microbial contaminants from the spacecraft model with their subsequent deposition in the surrounding area. It is concluded that different planetary protection cleanliness levels for different parts of a spacecraft do not necessarily prevent soil contamination because these cleaning strategies evolved without consideration of the effects of the descent engine plumes.

Type
Research Article
Copyright
Copyright © Cambridge University Press 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Mehta, M., Renno, N.O., Marshall, J., Grover, M.R., Sengupta, A., Rusche, N.A., Kok, J.F., Arvidson, R.E., Markiewicz, W.J., Lemmon, M.T. & Smith, P.H. (2010). Explosive erosion during the Phoenix landing exposes subsurface water on Mars, Icarus 211 (Issue 1), doi:10.1016/j.icarus.2010.10.003, 172194.CrossRefGoogle Scholar
Metzger, P.T., Immer, C.T., Donahue, C.M., Vue, B.T., Latta, R.C. & Deyo-Svendsen, M. (2009). Jet-induced cratering of a granular surface with applications to lunar spaceports. J. Aerosp. Eng. 22, 1.CrossRefGoogle Scholar
NASA (1999). Biological Contamination Control for Outbound and Inbound Planetary Spacecraft. NASA Policy Document (NPD) 8020.7F, NASA, Washington, DC. Available at http://planetaryprotection.nasa.gov.Google Scholar
NRC (1992). Biological Contamination of Mars: Issues and Recommendations. National Academy Press, Washington, DC.Google Scholar
Rummel, J. & Billings, L. (2004). Issues in planetary protection: Policy, protocol and implementation. Space Policy 20, 4954.CrossRefGoogle Scholar
Scott, R.F. & Ko, H.-Y. (1968). Transient rocket-engine gas flow in soil. AIAA J., 6.2, 258264.CrossRefGoogle Scholar
Sizemore, H.G., Mellon, M.T., Searls, M.L., Lemmon, M.T., Zent, A.P., Heet, T.L., Arvidson, R.E., Blaney, D.L. & Keller, H.U. (2010). In situ analysis of ice table depth variation in the vicinity of similar rocks at the Phoenix landing site. J. Geophys. Res. 115, E00E09, doi:10.1029/2009JE003414.Google Scholar
Smith, et al. (2009). Water at the Phoenix landing site. Science 325, 5861.CrossRefGoogle Scholar