Experiences with operations and autonomy of the Mars Pathfinder Microrover

TLDR

The Microrover Flight Experiment (MFEX), a NASA OACT flight experiment integrated with the Mars Pathfinder lander, landed on Mars on July 4, 1997. The study aimed to have the MFEX rover perform terrain navigation and contingency response under supervised autonomous control. MFEX operated under a once‑per‑sol command schedule, with daily goal locations set by Earth operators, and used supervised autonomous control to navigate terrain, deploy its APXS, image features, and autonomously detect and avoid hazards during traverses. In 30 sols, the Sojourner microrover completed all primary and extended objectives, demonstrating a unique capability to autonomously navigate unmodeled environments by selecting actions based on sensor input.

Abstract

The Microrover Flight Experiment (MFEX) is a NASA OACT (Office of Advanced Concepts and Technology) flight experiment which, integrated with the Mars Pathfinder (MPF) lander and spacecraft system, landed on Mars on July 4, 1997. In the succeeding 30 sols (1 sol=1 Martian day), the Sojourner microrover accomplished all of its primary and extended mission objectives. After completion of the originally planned extended mission, MFEX continued to conduct a series of technology experiments, deploy its alpha proton X-ray spectrometer (APXS) on rocks and soil, and image both terrain features and the lander. This mission was conducted under the constraints of a once-per-sol opportunity for command and telemetry transmissions between the lander and Earth operators. As such, the MFEX rover was required to carry out its mission, including terrain navigation and contingency response, under supervised autonomous control. For example, goal locations were specified daily by human operators; the rover then safely traversed to these locations. During traverses, the rover autonomously detected and avoided rock, slope, and drop-off hazards, changing its path as needed before turning back towards its goal. This capability to operate in an unmodeled environment, choosing actions in response to sensor input to accomplish requested objectives, is unique among robotic space missions to date.