NASA Keeps Their Spirit Up

Posted 13 Aug 2004 at 15:43 UTC by steve

Spirit, one of two NASA robots currently exploring Mars has exceeded its life span and is showing signs of wear, but it's still running and still sending back new photos. A new Nature article describes the aging rover's biggest problems: the batteries are running low due to weak winter sunlight and the gearbox on right front wheel has developed a fault. NASA engineers have instructured the rover to drive backwards, which reduces the excessive current being drawn by the front wheel. The weak light on Mars now allows only enough battery power for an hour or two of activity each day. Mars and Earth will be out of communications for a week around September 10 and the current plan is to have Spirit hibernate all week while it's batteries recharge. Despite the problems Spirit has traveled over 3 kilometers from its landing site and is now halfway up the 200 meter-high Columbia Hills.

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Maxon motors..., posted 13 Aug 2004 at 17:20 UTC by onnimikki » (Master)

Interesting... they're using Maxon RE20 Motors. I'd like to find out more about the particular problem... does anyone know where I can find more details about the problem? We had some issues with a bad batch of Maxon gearheads (on RE35 motors) last year. Maxon USA was very reluctant to admit that there could be a problem with their motors. It turns out that they machined the gearheads with incorrect tolerances, leading to our gearheads jamming up. The motors we've received since have been pretty good overall.

gearhead problems, posted 13 Aug 2004 at 18:42 UTC by steve » (Master)

All I've read about it is that the problem is in the gearhead itself. The motor and wheel are still working but the motor is drawing much more current than normal due to the gearhead issue.