AI for Mars Express: MEXAR2

MEXAR2 in action

The result of this work is a new 'smart' tool, dubbed MEXAR2 ('Mars Express AI Tool'), which has successfully passed initial testing and validation and is now an integral part of the Mars Express mission planning system.

MEXAR2 works by considering the variables that affect data downloading - including the overall science observation schedule for all Mars Express instruments - and then intelligently projecting which on-board data packets might be later lost due to memory conflicts. It then optimises the data download schedule and generates the commands needed to implement the download. "With MEXAR2, any loss of stored data packets has been largely eliminated," says Fred Jansen, ESA's mission manager for Mars Express.

Europe's first deep-space mission to fly with AI

MEXAR2 has reduced the mission planning team's workload considerably - by 50 percent compared to the old manual method - for generating workable downlink plans. "And because it optimises bandwidth used to receive data on Earth, we have been able to free expensive ground station time for other missions," says Michel Denis, Mars Express Spacecraft Operations Manager at ESOC.

ESA's Perth station tracks Mars Express

MEXAR2 recently won the 'best application' award at ICAPS 2007, a benchmark international conference for AI planning & scheduling technology.

"During MEXAR2's development, the flexibility of AI-based technology let us capture many specific requirements that would otherwise have needed costly software specification redesign" says Nicola Policella, AI research fellow at ESOC. "The use of a model-based approach enabled us to rapidly improve the software prototype to produce an effective mission planning application in a short time."

MEXAR2 on the global stage

MEXAR2 was also recently mentioned as one of three outstanding AI applications for mission operations by Dr Ari Kristinn Jónsson, formerly a research scientist at NASA's Ames Research Center, in a keynote speech given at iSAIRAS 2008, the 9th International Symposium on Artificial Intelligence, Robotics and Automation for Space.

"It should be noted, that - like the very few other AI tools in spacecraft operations - MEXAR2 is a trailblazer in bringing AI technology to spacecraft operations. The effectiveness of the tool and the benefits it has provided are therefore significant accomplishments in themselves," says Dr Jónsson, who is now Dean of the School of Computer Science at Reykjavik University, Iceland.

Artificial intelligence provides solutions for complex problems, and has now entered the space mission operations field as a value-adding technology. "Mars Express is the first European deep-space exploration mission to fly using an AI tool on the ground, and the technology is boosting science return while reducing time and resource costs," adds Donati.

AI can help solve other mission operations problems

EXOMARS rover - artist's concept

With MEXAR2's proven success, scientists at both ESOC and ISTC-CNR are working to apply the current AI technology to other problems.

Successful recent work includes the reverse problem of how to optimise the upload of commands to Mars Express, in a project dubbed - somewhat tongue-in-cheek - as 'RAXEM' - for the 'Reverse of MEXAR'.

ESA-developed AI technology will also be applied to the 'Advanced Planning & Scheduling Initiative', which is designed to provide AI benefits to other areas and missions, including long term observation for ESA's Integral, an orbiting space observatory mission.

"It's possible to apply the same AI concepts to future missions, like ExoMars, Europe's first planetary rover mission to the Red Planet," says Donati, adding, "Today's achievement is the starting point for implementing new on-board autonomy concepts for ESA's challenging missions of the future."

Editor's note

See related article "Artificial intelligence for robotic exploration: Q&A with Ari Kristinn Jónsson" via link at top right.