Thermal Design, Analysis, and Sensitivity of a Sample Tube on the Martian Surface

Date

2017-07-16

Journal Title

Journal ISSN

Volume Title

Publisher

47th International Conference on Environmental Systems

Abstract

NASA will launch a rover to Mars in 2020 to collect and cache samples of Martian rocks and regolith for potential return to Earth on a future mission. The collected samples will be placed in tubes, hermetically sealed, and deposited on the surface of Mars for a period of up to 10 years. Preventing the deposited samples from overheating is an important consideration in order to ensure their scientific integrity. The samples are required to remain below 60 °C, however there is a goal to keep them below 40 °C. This temperature requirement is challenging, considering that the maximum surface temperature of Mars is 38 °C and the tube must be thermally controlled through only passive means. As a result, a significant effort has been made to design a tube to contain the samples and investigate innovative tube surface treatments that maintain proper sample temperatures without significant adverse effects of sample contamination. The tube uses a specialized aluminum oxide coating to prevent overheating on the Martian surface. The maximum predicted tube temperature is relatively insensitive to local thermal inertia, ground contact, and ground slope, but is very sensitive to landing site latitude. The maximum predicted sample temperature in the +/- 30° landing latitude range with worst case assumptions is 54 °C, but many of the potential landing sites have significantly cooler maximum predicted sample temperatures. This paper describes the thermal design, analysis, and sensitivity studies performed on the sample tubes and also discusses operational considerations.

Description

Matthew Redmond, NASA Jet Propulsion Laboratory (JPL), USA
Sarah Sherman, Jet Propulsion Laboratory, USA
Pradeep Bhandari, Jet Propulsion Laboratory, USA
Keith Novak, Jet Propulsion Laboratory, USA
ICES102: Thermal Control for Planetary and Small Body Surface Missions
The 47th International Conference on Environmental Systems was held in South Carolina, USA on 16 July 2017 through 20 July 2017

Keywords

passive thermal control, design, analysis, sensitivity

Citation