Andrew Mishkin

Experiences with operations and autonomy of the Mars Pathfinder Microrover

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.

Robotic vehicles for planetary exploration

Future missions to the moon, Mars, or other planetary surfaces will use planetary rovers for exploration or other tasks. Operation of these rovers as unmanned robotic vehicles with some form of remote or semi-autonomous control is desirable to reduce the cost and increase the capability and safety of many types of missions. However, the long time delays and relatively low bandwidths associated with radio communications between planets precludes a total “telepresence” approach to controlling the vehicle. A program to develop planetary rover technology has been initiated at the Jet Propulsion Laboratory (JPL) under sponsorship of the National Aeronautics and Space Administration (NASA). Developmental systems with the necessary sensing, computing, power, and mobility resources to demonstrate realistic forms of control for various missions have been developed and initial testing has been completed. These testbed systems, the associated navigation techniques currently used and planned for implementation, and long-term mission strategies employing them are described.

Working the Martian night shift - the MER surface operations process

The Mars exploration rover mission has conducted continuous Mars surface operations for over 24 months to date. The operations processes and tools put in place before landing have continued to develop throughout the surface mission, evolving from a capability intended to operate for less than four months to one capable of continuing indefinitely. The MER operations design has been accepted as baseline for the Mars Science Laboratory mission, scheduled for launch in 2009. Our experiences during MERs exciting and unexpectedly extensive surface exploration phase may provide useful insights for other future long duration surface missions

A Vision System For A Mars Rover

A Mars rover must be able to sense its local environment with sufficient resolution and accuracy to avoid local obstacles and hazards while moving a significant distance each day. Power efficiency and reliability are extremely important considerations, making stereo correlation an attractive method of range sensing compared to laser scanning, if the computational load and correspondence errors can be handled. Techniques for treatment of these problems, including the use of more than two cameras to reduce correspondence errors and possibly to limit the computational burden of stereo processing, have been tested at JPL. Once a reliable range map is obtained, it must be transformed to a plan view and compared to a stored terrain database, in order to refine the estimated position of the rover and to improve the database. The slope and roughness of each terrain region are computed, which form the basis for a traversability map allowing local path planning. Ongoing research and field testing of such a system is described.

Human-Robotic Missions to the Moon and Mars: Operations Design Implications

For most of the history of space exploration, human and robotic programs have been independent, and have responded to distinct requirements. The NASA Vision for Space Exploration calls for the return of humans to the Moon, and the eventual human exploration of Mars; the complexity of this range of missions will require an unprecedented use of automation and robotics in support of human crews. The challenges of human Mars missions, including roundtrip communications time delays of 6 to 40 minutes, interplanetary transit times of many months, and the need to manage lifecycle costs, will require the evolution of a new mission operations paradigm far less dependent on real-time monitoring and response by an Earthbound operations team. Robotic systems and automation will augment human capability, increase human safety by providing means to perform many tasks without requiring immediate human presence, and enable the transfer of traditional mission control tasks from the ground to crews. Developing and validating the new paradigm and its associated infrastructure may place requirements on operations design for nearer-term lunar missions. The authors, representing both the human and robotic mission operations communities, assess human lunar and Mars mission challenges, and consider how human-robot operations may be integrated to enable efficient joint operations, with the eventual emergence of a unified exploration operations culture.

Autonomous Navigation and Control of a Mars Rover

Abstract A Mars Rover will nerd to be able to navigate autonomously kilometers at a time. This paper outlines the sensing, perception, planning, and execution monitoring systems that are currently being designed for the rover. The sensing system is based around sicreo vision. The interpretation of the images use a registration of the depth map with a global height map provided by an orbiting spacecraft. Safe, low energy paths are then planned through the map, and expectations of what the rovers articulation sensors should sense arc generated. These expectations are then used to ensure that the planned path is correctly being executed.

Mars rover local navigation and hazard avoidance

A Mars rover sample return mission has been proposed for the late 1990s. Due to the long speed-of-light delays between Earth and Mars, some autonomy on the rover is highly desirable. JPL has been conducting research in two possible modes of rover operation, Computer-Aided Remote Driving and Semiautonomous Navigation. A recently-completed research program used a half-scale testbed vehicle to explore several of the concepts in semiautonomous navigation. A new, full-scale vehicle with all computational and power resources on-board will be used in the coming year to demonstrate relatively fast semiautonomous navigation. The computational and power requirements for Mars rover local navigation and hazard avoidance are discussed.

Autonomously generating operations sequences for a Mars rover using AI-based planning

This paper discusses a proof-of-concept prototype for ground-based automatic generation of validated rover command sequences. This prototype is based on ASPEN (Automated Scheduling and Planning Environment). This Artificial Intelligence (AI) based planning and scheduling system will automatically generate a command sequence that will execute: within resource constraints and satisfy flight rules. An automated planning and scheduling system encodes rover design knowledge and uses the search and reasoning techniques to automatically generate low-level command sequences while respecting the rover operability constraints. This prototype planning system has been field-tested using the Rocky-7 rover at JPL, and will be field-tested on more complex rovers to prove its effectiveness before transferring the technology to flight operations for an upcoming NASA mission. The goal-driven commanding of planetary rovers greatly reduces the requirements for highly skilled rover engineering personnel. This in turn greatly reduces mission operations costs and permits a faster response to changes in rover states.

Automated Scheduling of Personnel to Staff Operations for the Mars Science Laboratory

Leveraging previous work on scheduling personnel for space mission operations, we have adapted ASPEN (Activity Scheduling and Planning Environment) [1] to the domain of scheduling personnel for operations of the Mars Sci ence Laboratory. Automated scheduling of personnel is not new. We compare our representations to a sampling of employee scheduling systems available with respect to desire d features. We described the constraints required by MSL personnel schedulers and how each is handled by the scheduling algorithm.

AUTONOMOUS NAVIGATION AND CONTROL OF A MARS ROVER

A Mars Rover will need to be able to navigate autonomously kilometers at a time. This paper outlines the sensing, perception, planning, and execution monitoring systems that are currently being designed for the rover. The sensing system is based around stereo vision. The interpretation of the images use a registration of the depth map with a global height map provided by an orbiting spacecraft. Safe, low energy paths are then planned through the map, and expectations of what the rovers articulation sensors should sense are generated. These expectations are then used to ensure that the planned path is correctly being executed.