Thursday, November 16, 2006

Retirement Planning for Real?

There is just one thing I can promise you about the outer space program: Your tax dollars will go farther. ~ Werner Von Braun

I want to be very clear on this: I had nothing to do with it. I knew nothing in advance, I've got no friends on Mars (well, except for my able assistant), and I had no communications with the satellite before it went bonkers.

Of course, I'm talking about Mars Global Surveyor, which has gone incommunicado for the last couple of weeks. After writing about satellite retirements, though, I feel like I put a general hex out into space, looking for a victim. To bring you up to date, MGS, which has been returning high-quality pictures from Mars for nearly 10 years. MGS was to spend a Martian year photographing the planet as it went through seasonal changes, but, like the rovers, it was working so well that its mission was extended a couple of times.

In fact, MGS has been up there so long, it's become part of a crowd, what with Odyssey and the Mars Reconnaissance Orbiter (MRO) having arrived to look for water. Good a job as MGS has done, MRO takes things to a new level, taking pictures with such a high resolution, they can clearly show the rover Opportunity and its shadow). MRO has a new assignment right now, though: Find MGS and take its picture.

Back on November 5, MGS phoned home to say that it was having a problem with one of its two solar panels. Since the panels provide all the power for the satellite (there's no RTG), the loss of 50% of its power-generating ability was potentially serious. Soon after sending the message, MGS went silent, except for a brief transmission that seemed to indicate that it had gone into safe mode.

“Safe mode” is a condition used by satellite computers when something has gone seriously wrong. Basically, a condition has occurred which the device can't deal with, so it essentially “reboots” and sends an identification signal to let Earth know where it is. Then it waits for instructions. Unfortunately, since no one has heard from MGS, we can't say for sure where it is. If one of the panels has gone bad, it's possible that the satellite turned its remaining operational panel into a position to maximize the power generation. Unfortunately, this could result in the probe's antenna pointing in the wrong direction to communicate with ground controllers.

Ideally, once it's batteries were charged, the satellite would occasionally turn toward Earth and operate off battery long enough to communicate. But, it doesn't seem to be doing that. So, the MGS team has asked the MRO folks to try to find and photograph MGS. Assuming MRO can find MGS, given MRO's resolution capabilities, it's just possible the team might see enough detail to be able to formulate a plan to recover the Surveyor.

Even the rovers might get into the act. There is a possibility that Opportunity and/or Spirit could pick up a beacon signal from the ailing spacecraft. If they can, then the team might be able to get a fix on its position. It's a long shot, but no one is ready to give up.
The biggest problem is that time is running out. If enough power isn't being generated, MGS might not be able to communicate anymore.

Wayne Sidney, the MRO Flight Engineering Team Lead, is quoted in the Space.com article, pointing out that, even if MGS can't be recovered, it's been a game trooper that has been operational from Mars longer than any other satellite or lander. In other words, even if MGS has gone to the old satellite's home, no one can complain about its performance. Like the rovers, the Voyagers, Galileo, and the Pioneers, it has worked longer and better than anyone hoped. As I've said before, when we get it right, we really get it right.

He also mentioned that November 7 would have been the tenth anniversary of MGS in space. By coincidence, that was the very day that MRO fired up its main science equipment. “It really seems like there's fate involved in all this,” said Mr. Sidney. “MGS knew it was time to retire.”

I swear it wasn't my doing.

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