When Cosmic Rays Attack: The MRO in Safe Mode

I always get concerned when I hear about one of our invaluable robotic explorers switching into safe mode. This time, it is the turn of NASA’s Mars Reconnaissance Orbiter (MRO) that re-booted itself after an “event” in Mars orbit. It seems likely that a direct cosmic ray hit could be to blame…

Fortunately, it appears engineers have good news from the MRO, it seems to be recovering well after it unexpectedly rebooted on Monday morning. Although the MRO has experienced these events in the past (5 times since 2005), this cosmic ray event has a different profile to the rest. This time, the spacecraft experienced a brief spike in power load, causing the onboard systems to protect themselves by turning off non-essential systems.

Much like if your PC suffers a software fault and you have to turn it off, only to find an option to re-boot in “safe-mode” so you can identify the problem with minimal programs and drivers running; the MRO has pretty much done the same thing. A surge in power triggered a re-boot and then a diagnostic safe-mode to protect the sensitive computers and instrumentation from damage. This has given NASA engineers some time to restart the satellite and ensure everything is working as it should. NASA is confident the MRO should be fully operational within the coming days.

The event lasted between 200 nanoseconds and 41 seconds, and it seems likely that a cosmic ray hit hardware that monitors power usage. When the high-energy particle hit, a false power reading was generated and the fail safe was enacted. Although the profile of this event differs from previous cosmic ray hits, NASA scientists are confident they have rooted out the problem.

“We are going to bring the spacecraft back to normal operations, but we are going to do so in a cautious way, treating this national treasure carefully,” said Jim Erickson of NASA’s Jet Propulsion Laboratory, Pasadena, California.

For more, check out Nancy Atkinson’s Universe Today post: MRO Goes Into Safe Mode