elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Contact | Deutsch
Fontsize: [-] Text [+]

The Apollo Lunar heat flow experiment revisited: A critical reassessment of the in-situ thermal conductivity determination

Grott, M. and Knollenberg, J. and Krause, C. (2010) The Apollo Lunar heat flow experiment revisited: A critical reassessment of the in-situ thermal conductivity determination. Journal of Geophysical Research, 115 (E11005), pp. 1-11. DOI: doi:10.1029/2010JE003612.

Full text not available from this repository.

Official URL: http://www.agu.org/pubs/crossref/2010/2010JE003612.shtml

Abstract

Lunar heat flow was determined in situ during the Apollo 15 and 17 missions, but some uncertainty is connected to the value of the regolith's thermal conductivity, which enters as a linear factor into the heat flow calculation. Different approaches to determine the conductivity yielded discordant results, which led to a downward correction of the obtained heat flow values by 30%–50% subsequent to the publication of the first results. We have reinvestigated likely causes for the observed discrepancies and find that neither poor coupling between the probe and regolith nor axial heat loss can explain the obtained results. Rather, regolith compaction and compression likely caused a local increase of the regolith's thermal conductivity by a factor of 2–3 in a region which extends at least 2–5 cm from the borehole wall. We conclude that the corrected lunar heat flow values, which are based on thermal diffusivity estimates sampling a large portion of undisturbed regolith, represent robust results. Future in situ measurements of regolith thermal conductivity using active heating methods should take care to both minimize regolith disturbance during probe emplacement and maximize heating time to obtain reliable results. We find that for the Apollo measurements, heating times should have exceeded at least 100 h, and ideally 200 h.

Document Type:Article
Title:The Apollo Lunar heat flow experiment revisited: A critical reassessment of the in-situ thermal conductivity determination
Authors:
AuthorsInstitution or Email of Authors
Grott, M.matthias.grott@dlr.de
Knollenberg, J.joerg.knollenberg@dlr.de
Krause, C.christian.krause@dlr.de
Date:2010
Journal or Publication Title:Journal of Geophysical Research
Refereed publication:Yes
In Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:115
DOI:doi:10.1029/2010JE003612
Page Range:pp. 1-11
Status:Published
Keywords:Moon, Apollo, heat flux, thermal conductivity, regolith
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W EW - Erforschung des Weltraums
DLR - Research area:Space
DLR - Program:W EW - Erforschung des Weltraums
DLR - Research theme (Project):W - Vorhaben Vergleichende Planetologie (old)
Location: Köln-Porz , Berlin-Adlershof
Institutes and Institutions:Institute of Space Systems
Institute of Planetary Research > Planetary Physics
Institute of Planetary Research > Asteroids and Comets
Institute of Planetary Research
Deposited By: Lena Noack
Deposited On:13 Dec 2010 12:22
Last Modified:23 Jan 2014 11:36

Repository Staff Only: item control page

Browse
Search
Help & Contact
Informationen
electronic library is running on EPrints 3.3.12
Copyright © 2008-2012 German Aerospace Center (DLR). All rights reserved.