Originally designed for a mission lasting one Martian year (about two Earth years), MEX <https://www.theregister.co.uk/2020/03/31/mars_express/> continues to operate even today, and looks likely to manage to stay in action for a few more years. Working around a wiring error that meant it only had 70% of the designed operating power, then dealing with unreliabilities cropping up in the Solid-State Mass Memory system, figuring out how to prolong the life of the maneouvring reaction wheels, actually having to write and upload new software written in Ada-83, where the original contractor was helpful, rather than obstructive for a change: While support had officially ended, ESA did set up a small contract with Airbus (who had acquired the original spacecraft manufacturer) in a role reversal that saw Airbus review the MEX team's work rather than the other way around. As it transpired, Airbus turned out to be hugely helpful, blowing dust off some testing tools, making suggestions and, effectively, "putting the band back together" as those who originally designed and built MEX (and had not yet shuffled off into retirement) were hauled back to offer assistance. All in all, the team operating MEX has done some amazing work so far. Bear in mind that launching probes into space is still a dicey business, prone to embarrassing failures. This is why they have to be over-engineered, then backed up with alternate recovery plans on top of alternate recovery plans.