Original URL: http://www.theregister.co.uk/2011/11/02/mars_express_fix/

Mars probe crippled by buggy SSD successfully jury-rigged

Ingenious space BOFHs overcome memory fault

By Team Register

Posted in Science, 2nd November 2011 15:46 GMT

Exclusive A space probe in orbit above Mars, crippled by a fault in its solid-state memory, has been brought back on line and is now once again handling scientific data.

The Mars Express spacecraft, which has been orbiting the Red Planet since 2003, has been suffering problems since August in which it has repeatedly gone into "safe mode" due to read/write errors and communications problems in its Solid State Mass Memory (SSMM) system. Repeated safe-modes are bad news, as going into safe mode involves the craft needing to lock onto the Sun to ensure that its solar panels keep its batteries charged – and this means burning six months' normal consumption of manoeuvring fuel. Since August, Mars Express has gone into safe mode three times and could easily have done so more often. Prior to the SSMM problems, the most recent safe-mode event had been three years ago.

The latest update as of 31 October issued by the European Space Agency (ESA), operator of Mars Express, states that a work-around is "now being investigated", but persons familiar with the matter have informed The Register that in fact the workaround is in place and science operations with one instrument – the Sub-Surface Sounding Radar Altimeter (MARSIS) – have resumed. More instruments are expected to come back online in coming weeks.

In essence the fix involves repurposing a memory file located outside the buggy SSMM to store commands from controllers on Earth, which should prove more reliable than using either the normal SSMM file or its "B-side" backup, which has already been tried without success. The crafty fix seems to have done the business for now, successfully bringing back to life a multimillion-pound spacecraft in orbit about another planet currently well over a hundred million miles away.

Who said fixing IT problems is boring? ®