What to do when the help desk is 160 million miles away
Is it just me, or do the technology teams at NASA just keep getting more and more impressive? Not long after Curiosity’s landing on Mars, they reprogrammed the rover in an operation that almost amounted to reinstalling its entire OS. That would be a big challenge on a normal day, but even more so when the computer you are working on is 160 million miles away with nobody around to hit the reset key if things go badly.
The problem with Curiosity is the same one that Pathfinder had back when I was reporting on that robot in 1998. There is only so much power a roving interplanetary robot can support. And there are also the harsh conditions to deal with on the red planet.
Curiosity has a somewhat weak processor, less powerful than the ones used in current smart phones, and not much storage capacity, only 4G total, although there is plenty of radiation shielding.
NASA engineers ended up with a robot that couldn’t store both landing instructions and exploration commands. So once the landing was complete, a patch was needed so that the robot could start exploring. Landing information was erased to make room, since Curiosity will never need to know how to do that again.
The patching was a delicate process that took four days to complete. The last thing scientists wanted was to introduce a blue screen of death to a robot so far away from technical support. It takes 14 minutes to send a command to Curiosity and another 14 minutes to get a response back. So they proceeded slowly.
First, the new information was uploaded to Curiosity’s primary computer system, but held in memory so if something went wrong, it would fix itself when the system rebooted from its disk the next day. All went well, so the following day the same commands were loaded into permanent memory. The next day the same process began with the backup computer because NASA wasn’t taking any chances.
The patch worked, and now we are getting all sorts of cool pictures and data from Mars, including evidence that there might have once been water there. But remember, all that was dependent on perhaps the most difficult and certainly the longest-distance patching operation in history.
It’s difficult for me to know what to be more impressed with, the data the robot is gathering or the patch that made it possible.
Perhaps I’ll just sit back in awe of NASA in general.
Posted by John Breeden II on Oct 03, 2012 at 9:39 AM