The European Space Agency’s (ESA) Mars Express Orbiter is poised to receive a new software update. According to the company, the code will have to travel over 93 million miles (150 million km) of space.
Mars Express has been collecting data in orbit for nearly 15 years. When the spacecraft arrived at Mars in December 2003, researchers allotted for only a two-year mission timespan. Pushing well past its original end date, Mars Express has only shown some minor performance degradation. However, the main issue resides in the orbiter’s gyroscopes (gyros). According to ESA, they are close to failing.
The six gyros are in charge of the rotation measurements of Mars Express’ three axes. This data combines with two startrackers, which are point-and-shoot cameras, to determine its orientation in space.
“After looking at variations in the intensity of the gyros’ internal lasers, we realized last year that, with our current usage, four of the six gyros were trending towards failure,” says James Godfrey, spacecraft operations manager. “Mars Express was never designed to fly without its gyros continuously available, so we could foresee a certain end to the mission sometime between January and June 2019.”
ESA engineers came up with a plan: they would try to fly the orbiter using its startrackers, extending the gyros lifespan by reducing their usage. This plan would require rewriting 15-year-old software.
Teams across ESA came together to open the code, perform a software update, and prepare it for upload. After a huge effort, the new software was finalized this year and has since undergone extensive testing.
“We were also helped by being able to take code flown on Rosetta and transplant it into the Mars Express guidance software,” says Simon Wood, operations engineer. Rosetta was a previous ESA space probe, named after the Rosetta Stone.
ESA recently uploaded the rewritten code to an area of space memory, but in order to proceed with the installation, Mars Express will have to be shut down and rebooted. This step is scheduled for Monday, April 16, 2018.
If all goes smoothly, ESA will conduct two weeks of reconfiguration to ensure Mars Express is back to normal operations.
“Similar, but much smaller fixes, have been developed in the past for other missions with old gyros, such as Rosetta, but this is certainly the most complex and extensive software rewrite we’ve done in recent memory,” says Patrick Martin, mission manager.
According to ESA, Mars Express could enjoy the 2020s, depending on fuel supply, thanks to the software revisions.
Filed Under: Aerospace + defense
