Mars Express, or AI to the Rescue

Mars Express has never received the kind of media attention as Mars Rover. Probably because a mobile robot like Mars Rover is a lot more exciting than something that hangs around collecting scientific data, which is Mars Express' job. But for several years now, Mars Express has been studying the atmosphere, surface, and subsurface of the planet Mars, divining for water and forms of life.

As you might expect, all this involves huge amounts of data that needs to be downloaded to Earth on a scheduled basis. And if not sent at the right time and in the right sequence, that data can be lost forever. To now, engineers managed a tedious, error-prone downloading process using software to generate command sequences sent to Mars Express, instructing it what to do with what and when. According to Alessandro Donati of the Advanced Mission Concepts and Technologies Office at the European Space Agency, part of the problem involves multiple, constantly changing variables--spacecraft orientation, ground-station availability, space-ground communication bandwidth, on-board storage availability, and the like. A scheduling and optimization nightmare, in other words.

Addressing scheduling and optimization problems such as these, researchers at Italy's Institute for Cognitive Science and Technology (ISTC-CNR) have developed an AI tool called MEXAR2 (short for "Mars Express AI Tool"). MEXAR2--which is written in Java and runs on Unix, Linux, Windows, and Mac OS X--works by considering the variables that affect data downloading, then intelligently projecting which on-board data packets might be later lost due to memory conflicts. The program then optimizes the download schedule and generates the commands needed to implement the download.

According to engineers who use it, MEXAR2 has reduced the mission planning team's workload by 50 percent. Moreover, the optimized bandwidth has freed up expensive ground station time for other missions, according to Michel Denis, Mars Express Spacecraft Operations Manager.

-- Jonathan Erickson
jerickson@ddj.com

Posted by Jon Erickson at 04:57 PM  Permalink