skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: RTGs Using PbTe/TAGSThermoelectric Elements for Mars Environmentatl Survey (MESUR) Mission

Abstract

The paper describes the results of studies on an RTG option for powering the global network of unmanned landers for NASA's Mars Environmental Survey (MESUR) mission. RTGs are essentially unaffected by diurnal and seasonal variations, Martian sandstorms, and landing site latitudes, and their waste heat can stabilize the temperatures of the landers and their payload. The RTG designs described in this paper are based on PbTe/TAGS Thermoelectric elements, in contrast to the SiGe-based RTGs the author described in previous publications. The RTGs described here differ not only in the choice of thermoelectric materials but also in the use of much lower operating temperatures, conductive rather than radiative heat transfer, an inert cover gas instead of vacuum in the RGG's converter, and fibrous instead of multifoil thermal insulation. As in a previous Teledyne design, the Fairchild designs described in this paper employ flight-proven General Purpose Heat Source modules and Close-Pack Arrays of thermoelectric converter modules. Illustrative point designs of RTGs producing 41 and 51 watts(e) at 28 volts are presented. The presented performance parameters were derived by detailed thermal, thermoelectric, and electrical analyses (including radiator geometry optimization) described in the paper. The Fairchild study resulted in modifications of the Teledyne designmore » to permit scale-up to higher power levels, and to ensure adequate fuel clad ductility at launch temperatures and adequate thermal conductance from the thermoelectric cold ends to the RTG housing. There are three duplicate copies. One copy is in the FSC-ESD files.« less

Authors:
Publication Date:
Research Org.:
Fairchild Space
Sponsoring Org.:
NE Office of Space and Defense Power Systems
OSTI Identifier:
1033397
Report Number(s):
FSC-ESD-217-92-509
Orbital ID: 9480; Call Number: 30-02
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
NESDPS Office of Nuclear Energy Space and Defense Power Systems; RTG; Mars; MESUR

Citation Formats

Schock, Alfred. RTGs Using PbTe/TAGSThermoelectric Elements for Mars Environmentatl Survey (MESUR) Mission. United States: N. p., 1992. Web. doi:10.2172/1033397.
Schock, Alfred. RTGs Using PbTe/TAGSThermoelectric Elements for Mars Environmentatl Survey (MESUR) Mission. United States. doi:10.2172/1033397.
Schock, Alfred. Wed . "RTGs Using PbTe/TAGSThermoelectric Elements for Mars Environmentatl Survey (MESUR) Mission". United States. doi:10.2172/1033397. https://www.osti.gov/servlets/purl/1033397.
@article{osti_1033397,
title = {RTGs Using PbTe/TAGSThermoelectric Elements for Mars Environmentatl Survey (MESUR) Mission},
author = {Schock, Alfred},
abstractNote = {The paper describes the results of studies on an RTG option for powering the global network of unmanned landers for NASA's Mars Environmental Survey (MESUR) mission. RTGs are essentially unaffected by diurnal and seasonal variations, Martian sandstorms, and landing site latitudes, and their waste heat can stabilize the temperatures of the landers and their payload. The RTG designs described in this paper are based on PbTe/TAGS Thermoelectric elements, in contrast to the SiGe-based RTGs the author described in previous publications. The RTGs described here differ not only in the choice of thermoelectric materials but also in the use of much lower operating temperatures, conductive rather than radiative heat transfer, an inert cover gas instead of vacuum in the RGG's converter, and fibrous instead of multifoil thermal insulation. As in a previous Teledyne design, the Fairchild designs described in this paper employ flight-proven General Purpose Heat Source modules and Close-Pack Arrays of thermoelectric converter modules. Illustrative point designs of RTGs producing 41 and 51 watts(e) at 28 volts are presented. The presented performance parameters were derived by detailed thermal, thermoelectric, and electrical analyses (including radiator geometry optimization) described in the paper. The Fairchild study resulted in modifications of the Teledyne design to permit scale-up to higher power levels, and to ensure adequate fuel clad ductility at launch temperatures and adequate thermal conductance from the thermoelectric cold ends to the RTG housing. There are three duplicate copies. One copy is in the FSC-ESD files.},
doi = {10.2172/1033397},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jul 01 00:00:00 EDT 1992},
month = {Wed Jul 01 00:00:00 EDT 1992}
}

Technical Report:

Save / Share:
  • This paper presents the results done to perform specialized RTG design studies. The analytical results indicate that a lander by itself experiences much higher g-loads than the lander with an integral penetrator; but that minor modifications of the shape of the lander can very substantially reduce the maximum g-load during landing, thus eliminating the need for retrorockets for RTG survival. Paper presented at the 27th IECEC in San Diego, CA August 3-7, 1992. Also included are four copies (3 bound) from Fairchild presentation.
  • The National Aeronautics and Space Administration (NASA) is studying a seven-year robotic mission (MESUR, Mars Environmental Survey) for the seismic, meteorological, and geochemical exploration of the Martian surface by means of a network of ~16 small, inexpensive landers spread from pole to pole. To permit operation at high Martian latitudes, NASA has tentatively decided to power the landers with small RTGs (Radioisotope Thermoelectric Generators). To support the NASA mission study, the Department of Energy's Office of Special Applications commissioned Fairchild to perform specialized RTG design studies. Those studies indicated that the cost and complexity of the mission could be significantlymore » reduced if the RTGs had sufficient impact resistance to survive ground impact of the landers without retrorockets. Fairchild designs of RTGs configured for high impact resistance were reported previously. Since the, the size, configuration, and impact velocity of the landers and the power level and integration mode of the RTGs have changed substantially, and the previous impact analysis has been changed substantially, and the previous impact analysis has been updated accordingly. The analytical results, reported here, indicate that a lander by itself experiences much higher g-loads than the lander with an integral penetrator; but that minor modifications of the shape of the lander can very substantially reduce the maximum g-load during landing, thus eliminating the need for retrorockets for RTG survival. There are three copies in the file and the Original Artwork is stored in the ESD files.« less
  • The paper describes the results of studies on an RTG option for powering the global network of unmanned landers for NASA's Mars Environmental Survey (MESUR) mission. RTGs are essentially unaffected by diurnal and seasonal variations, Martian sandstorms, and landing site latitudes, and their waste heat can stabilize the temperatures of the landers and their payload. The RTG designs described in this paper are based on PbTe/TAGS thermoelectric elements, in contast to the SiGe-based RTGs the author described in previous publications. The presently described RTGs differ not only in the choice of thermoelectric materials but also in the use of muchmore » lower operating temperatures, conductive rather than radiative heat transfer, an inert cover gas instead of vacuum in the RTG's converter, and fibrous instead of multifoil thermal insulation. As in a previous Teledyne design, the Fairchild designs described in this paper employ flight-proven General Purpose Source modules and Close-Pack Arrays of thermoelectric converter modules. Illustrative point designs of RTGs producing 41 and 51 watts(e) at 28 volts are presented. The presented performance parameters were derived by detailed thermal, thermoelectric, and electrical analyses (including radiator geometry optimization) described in the paper. The Fairchild study showed that, with appropriate modifications, the Teledyne design can be scaled up to higher power levels, and it identified solutions to ensure adequate fuel clad ductility at launch temperatures and adequate thermal conductance from the thermoelectric cold ends to the RTG housing.« less