Updating Mars Express Software

Mars Express mission operators at ESOC successfully sent a new software patch that would allow the spacecraft to operate in its third decade.

In 2017, the flight control team noticed that four of the spacecraft’s six gyros were aging faster than expected, threatening to end the mission within two years. To save the mission, the solution was implemented and has been regularly updated ever since. Today the last upgrade would allow the spacecraft to function until 2034.

Updating a satellite designed in the 1990s can seem like software archaeology. Mission operators had to dig up 33-year-old Microsoft 3.1 to figure out which line of code needed to be edited and then work out by hand the changes before installing them to the star tracker's memory.