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Heat Flow

NSSDCA ID: 1972-031C-04

Mission Name: Apollo 16 Lunar Module /ALSEP
Principal Investigator:Dr. Marcus G. Langseth


The purpose of ALSEP experiment S-037 (heat-flow experiment -- HFE) was to determine the rate of heat loss from the lunar interior. To accomplish this, instrument probes were placed into two holes, about 3 m deep, drilled by an astronaut. The probes were to detect temperatures in the following ranges with corresponding accuracies noted in paranthesis -- (1) high sensitivity plus or minus 2 deg c (0.003 deg c) temperature difference, (2) low sensitivity plus or minus 20 deg c (0.03 deg c) temperature difference, (3) probe ambient temperatures in the range from 200 to 250 deg k (0.1 deg k), (4) thermocouple reference temperatures from -20 to 60 deg c (0.1 deg c), and (5) probe cable ambient temperatures from 90 to 250 deg k (0.3 deg k). Each of the two 1.2-m probes were to be inserted into the bore stem of a driller, which would remain in the drilled hole and act as a casing for the probe to prevent wall collapse during insertion. An electronics package was cable-connected to the probes and the central station. After drilling the first hole and emplacing the probes to this experiment, the cable connecting the heat-flow electronics package to the central station was inadvertently pulled loose from the connector on the central station, which rendered the experiment unusable.

Alternate Names

  • Apollo16ALSEP/HeatFlow
  • S037

Facts in Brief

Mass: 5.5 kg
Power (avg): 3.9 W

Funding Agency

  • NASA-Office of Applications (United States)


    Additional Information

    Questions and comments about this experiment can be directed to: Dr. David R. Williams



    NameRoleOriginal AffiliationE-mail
    Dr. Marcus G. LangsethPrincipal InvestigatorLamont-Doherty Geological Observatory
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