The Hardware Challenges for the Mars Exploration Rover Heat Rejection System

Abstract

The primary objective of the Mars Exploration Rover (MER) 2003 Project focused on the search for evidence of water on Mars. The launch of two identical flight systems occurred in June and July of 2003. The roving science vehicles are expected to land on the Martian surface in early and late January of 2004, respectively. The flight system design inherited many successfully features and approaches from the Mars Pathfinder Mission. This included the use of a mechanically-pumped fluid loop, known as the Heat Rejection System (HRS), to transport heat from the Rover to radiators on the Cruise Stage during the quiescent trek to Mars. While the heritage of the HRS was evident, application of this system for MER presented unique and difficult challenges with respect to hardware implementation. We will discuss these hardware challenges in each HRS hardware element: the integrated pump assembly, cruise stage HRS, lander HRS, and Rover HRS. These challenges span the entire development cycle including fabrication, assembly, and test. We will conclude by citing the usefulness of this system during launch operations, where in particular, the flight hardware inside the Rover was thermally conditioned by the HRS since there was no other effective means of maintaining its temperature. MISSION OVERVIEW & SPACECRAFT CONFIGURATIONIn August 2000, with less than three years to launch, NASA formally approved a dual rover mission to Mars. The Project was named the Mars Exploration Rover (MER) Project. The primary mission objectives were to determine the aqueous, climatic, and geologic history of a pair of sites on Mars where the conditions may have been favorable to the preservation of evidence of pre-biotic or biotic processes. The primary missions requirements were to deliver two identical rovers to the surface of Mars in order to conduct geologic and atmospheric investigations for at least FIGURE 1. Flight System Configuration Internally Nests Rover.

CO2 Insulation for Thermal Control of the Mars Science Laboratory

“…This paper will describe in detail this entire process, the results of these assessments and the final design that was implemented. 6,7 ). The external configuration of the MSL spacecraft is similar to that of MPF and MER.…”

Design of Accumulators and Liquid/Gas Charging of Single Phase Mechanically Pumped Fluid Loop Heat Rejection Systems

“…HE MSL mission, currently en route to Mars, follows the general design paradigm of the previous JPL rover missions to Mars (Mars Pathfinder, MPF 1,2,3,4,5 and Mars Exploration Rovers, MER 6,7 ). The external configuration of the MSL spacecraft looks similar to that of MPF and MER.…”

Mars Science Laboratory Launch Pad Thermal Control

“…HE mission follows the general design paradigm of the previous JPL rover missions to Mars (Mars Pathfinder, MPF 1,2,3,4,5 and Mars Exploration Rovers, MER 6,7 ). The external configuration of the MSL spacecraft looks similar to that of MPF and MER.…”