Thermal and Evolved Gas Analyzer: Part of the Mars Volatile and Climate Surveyor integrated payload
- Creators
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Boynton, William V.
- Bailey, Samuel H.
- Hamara, David K.
- Williams, Michael S.
- Bode, Rolfe C.
- Fitzgibbon, Michael R.
- Ko, WenJeng
- Ward, Michael G.
- Sridhar, K. R.
- Blanchard, Jeff A.
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Lorenz, Ralph D.
- May, Randy D.
- Paige, David A.
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Pathare, Asmin V.
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Kring, David A.
- Leshin, Laurie A.
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Ming, Douglas W.
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Zent, Aaron P.
- Golden, D. C.
- Kerry, Kristopher E.
- Lauer, H. Vern, Jr.
- Quinn, Richard C.
Abstract
The Thermal and Evolved Gas Analyzer (TEGA) on the Mars Polar Lander spacecraft is composed of two separate components which are closely coupled: a Differential Scanning Calorimeter (DSC) and an Evolved Gas Analyzer (EGA). TEGA has the capability of performing differential scanning calorimetry on eight small (0.038 mL) soil samples selected in the vicinity of the lander. The samples will be heated in ovens to temperatures up to 950°C, and the volatile compounds water and carbon dioxide, which are released during the heating, will be analyzed in the EGA. The power required by the sample oven is continuously monitored during the heating and compared to that required to heat simultaneously a similar, but empty, oven. The power difference is the output of the DSC. Both endothermic and exothermic phase transitions can be detected, and the data can be used in the identification of the phases present. By correlating the gas release with the calorimetry, the abundance of the volatile compounds associated with the different phases can be determined. The EGA may also be able to detect the release of oxygen associated with any superoxide that may be on the surface of the soil grains. The instrument can detect the melting of ice in the DSC down to abundances on the order of 0.2% of the sample, and it can detect the decomposition of calcite, CaCO₃, down to abundances of 0.5%. Using the EGA, TEGA can detect small amounts of water, down to 8 ppm in the sample, and it can detect the associated release of CO₂ down to the equivalent abundances of 0.03%. The EGA also has the ability to determine the ¹³C/¹²C ratio in the evolved CO₂, but it is not clear if the accuracy of this ratio will be sufficient to address the scientific issues.
Additional Information
The authors wish to thank the contributions of many individuals and organizations who contributed significantly to our ability to design, build, test, and deliver the TEGA instrument within the proposed budget. The instrument could not have been built without the hard labor and dedication of the staff of the LPL machine shop, Ron James and Bill Verts, and our electronics support from Rick Schmidt. The management and engineering team at the Jet Propulsion Laboratory were also especially helpful. This group consisted of Young Park, Barry Goldstein, Raul Romero, Mau Tran, David Nakamoto, and David Swenson. The staff at Jackson and Tull in Greenbelt, MD, Mike Cuviello and Phil Gill, who fabricated the electronics boards, were also very helpful and understanding of our deadlines. Local support from our documentarian, Mark Jackson, business manager, Heather Enos, and administrative associate, Glinda Davidson, was also critical in our getting the job done. David Kingery was a very helpful guru on advanced ceramics, a necessary component of our high-temperature ovens, and Mike Fontanarosa was very helpful in design of the field-programmable gate arrays. The support and dedication of many students who worked long and hard to maintain our computer systems (Chris Lewicki), fabricate our ovens (David Burke), construct the electronics (Richard McCord), develop software (Brennan Cropper, Dimitris Papamichail, Amy Mclaughlin, Zoltan Szilagyi, Vinit Deshpande, and Arivu Mani Ramasamy), and to test, test, and test the instrument (Ken Lempke, Gary Quadlander, and David Florkiewicz) are also especially appreciated. The support of numerous people who assisted in the integration and test activities at Lockheed Martin Astronautics (Jeff Slostad and Steve Bailey) is also greatly appreciated.Attached Files
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Additional details
- Eprint ID
- 119768
- Resolver ID
- CaltechAUTHORS:20230307-650451000.56
- Created
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2023-03-13Created from EPrint's datestamp field
- Updated
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2023-03-13Created from EPrint's last_modified field