MAPGEN: mixed-initiative planning and scheduling for the Mars Exploration Rover mission

Abstract

to elucidate the planet's past climate, water activity, and habitability.Science is MER's primary driver, so making best use of the scientific instruments, within the available resources, is a crucial aspect of the mission. To address this criticality, the MER project team selected MAPGEN (Mixed Initiative Activity Plan Generator) as an activity-planning tool.MAPGEN combines two existing systems, each with a strong heritage: the APGEN activity-planning tool 1 from the Jet Propulsion Laboratory and the Europa planning and scheduling system 2 from NASA Ames Research Center. This article discusses the issues arising from combining these tools in this mission's context. Combining systemsIn a most exciting development, two NASA roversnamed Spirit and Opportunity-were slated to arrive at the Red Planet in January, at two scientifically distinct sites. (Spirit arrived successfully on 3 January, with Opportunity scheduled to arrive 24 January-see Figures 1 and 2.) Each rover will have an operational lifetime of 90 sols (Martian days) or more and can traverse an integrated distance of one kilometer or more, although the maximum range from the landing site might be less. Scientifically, MER seeks to • Determine the aqueous, climatic, and geologic history of a site where on Mars conditions might have been favorable to the preservation of evidence of prebiotic or biotic processes • Identify hydrologic, hydrothermal, and other processes that have operated at the landing site • Identify and investigate Martian rocks and soils that have the highest-possible chance of preserving evidence of ancient environmental conditions and possible prebiotic or biotic activity • Respond to other discoveries revealed by rover-based exploration Each sol, operations personnel on Earth receive telemetry from the rovers. On the basis of the downloaded data, they must construct, verify, and uplink a detailed sequence of commands for the next sol to the rovers. Thus, operations personnel must formulate a viable sequence that satisfies the mission goals within tight deadlines. To help address this critical need, MAPGEN can automatically generate plans and schedules for science and associated engineering activities; assist in hypothesis testing, such as what-if analysis on various scenarios; support plan editing; analyze resource usage; and perform constraint enforcement and maintenance.APGEN has served as a multimission tool for several flight projects (including Cassini and Deep Impact), while Europa flew onboard NASA's Deep Space 1 as part of a technology experiment to demonstrate the first onboard T he Mars Exploration Rover mission is one of NASA's most ambitious science missions to date.Launched in the summer of 2003, each rover carries instruments for conducting remote and in situ observations

Mobile autonomous process sampling within coastal ocean observing systems

“…Deliberation in T-REX utilizes methods developed for applying mature computational techniques to command NASA space missions (Muscettola et al 1998;Jonsson et al 2000;Rajan et al 2000;Ai-Chang et al 2004;Bresina et al 2005). T-REX's architecture handles deliberation with modules called reactors, each of which is a planning and execution component.…”

Determining the value of information for collaborative multi-agent planning

“…This approach rests on the premise that people have good intuitions about how to solve certain planning (or scheduling) problems and that a planner working with a person can come up with better solutions than either operating alone. Several other mixed initiative approaches deploy collaborations between people and agents to produce better solutions for complex problems [38,1]. This work is complementary to ours.…”

“…It addresses in particular the problem of effectively computing the value of information an owner may have. 1 Determining the value of information requires scheduling and task knowledge, because information is valuable only to the extent it influences schedule changes. In many contexts in which ASAs operate, such task and scheduling knowledge resides in a scheduler module which is external to the CI [5,42,53].…”

VAL: automatic plan validation, continuous effects and mixed initiative planning using PDDL

“…This should be seen in the context of the worldwide efforts in space exploration and the NASA mobile robots missions currently being pursued on Mars. These missions also make extensive use of mixed-initiative planning aids, including MAPGEN [1], which has proved a very successful tool in the Mars Exploratory Rover missions.…”

“…This role of VAL has continued into the 4th IPC, which has included several minor extensions to PDDL and its semantics and consequently to VAL. The original definition of PDDL2.1 used in the 3rd IPC included features not used, in particular the expression of continuous change. Planning has traditionally been a subject of discrete change; a sequence of well defined discrete changes to a world state model (with a minority of ex- 1 Available at http://planning.cis.strath.ac.uk/VAL/ ceptions). Continuous change to numerical values has often been been modelled using discrete changes describing a step function.…”