Mars Rover's Wheel Stalls, Again

Mars Rover's Wheel Stalls, Again

By Emma Gallegos, Staff Writer
Posted: 12/04/2009

One of Spirit's wheels stalled again in the most recent attempt to drive the Mars rover out of the rut where it's spent the last seven months, a development JPL project manager John Callas called "troubling."

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This is the second wheel that has troubled Spirit's right side. Since March 2006, the 6-wheeled Spirit has been roving without the use of its right front wheel.

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The rover team has begun looking for clues in Spirit's history to explain what might be happening with this rear right wheel, and they are investigating an event that happened more than 260 sols - or Martian days - ago, before Spirit became stuck in the soil. The rear right wheel stalled momentarily while it was airborne - Spirit was doing a wheelie - and the other sets of wheels were making contact with the ground.

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The satellites orbiting Mars have been creating some problems for the rovers, too. The rovers team communicates via the NASA's Mars Odyssey and the Mars Reconnaissance Orbiter. The latter has been in a precautionary safe-mode since September. The former was put in safe-mode for the last week, but it came back on line - ready to relay signals between Spirit an Earth - late Thursday night.

Until then the rovers had to communicate directly with Earth - a trickier feat that requires the rovers to use more power sending their signals millions of miles to Earth, rather than a thousand miles to the orbiters.

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http://www.pasadenastarnews.com/ci_13931460

Just back the wrecker up to it...:D

Seriously, wasn't this related to the Rover getting stuck in WET sand recently? Saw a thread here yesterday about it.

This vehicle has been stuck for many months.

I bet they even had data that could have supported such a decision. But somehow they calculated the odds that they'd hit sand like this, and they decided it was low enough. :(

In this next photo, the middle size wheel is like that on Spirit and Opportunity. The large one is for the upcoming rover. The small one from Sojourner in the 90's.

Something like this:

Then drive on the whole side is lost.

Frankly, the amount of time this has worked indicates the approach they took was sound. How many years have these functioned, in an extremely harsh environment, with absolutely zero maintenance? Pretty amazing, really.

These rovers were designed to last something like 90 days... it's now five years later and they're just breaking down. I think six wheels seems to have been an excellent choice.