[aguywithamum]

Yeah, that's in reference to the failure of Beagle 2. It's on the page that was linked by Someone1234 (https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...).

[TorKlingberg]

The Beagle 2 and Mars Climate Orbiter are not the same thing. It is unknown why Beagle 2 failed and there is no reason to believe it was due to any unit mismatch. It may be that two of the solar panels failed to deploy.

[warkdarrior]

It's well known that the metric solar panels failed to deploy. The imperial solar panels opened successfully, but that did not generate enough electricity to keep going.