Spirit Rover Communications Error

cybrthng writes "Through yesterdays press release and the current Nasa Briefing there is news that they are having communications errors with contacting spirit. Is she lost or is it something akin to the Pathfinder failures that happened? Or did little green people claim an expensive tonka truck toy?"

Comments

not as bad as it sounds.

[mlyle]

A considerable number of things have to work properly for the rover to be in its present state. Mars Global Surveyor received a carrier on UHF but no data, confirming that the UHF antenna, amplifier, and tranmitter are functional. The fact that it transmitted at the correct time (at night) indicates batteries and power systems are at least mostly functional, and that the spacecraft computer/avionics system was able to calculate the time of the MGS pass.

Also, NASA's DSN (Deep Space Network) has been able to send commands asking Spirit to send tones on X-Band, and has received the response tones back. This confirms that at least the low gain antenna, antenna switch, x-band receiver, and x-band tone transmitter are functional.

Perhaps a software fault or a synchronization problem with the radios is preventing valid daa frames from being transmitted. The fact that so much is known to functional argues against a failure that will incapacitate the spacecraft indefinitely. In the coming days, if communications are not restored, the spacecraft will enter safe modes that cause it to try harder to transmit and will reset subsystems. I am optimistic at this point.

Re:not as bad as it sounds.

[bill_mcgonigle]

I am assuming that you have insider info? Or are you just playing the part?

He probably gets NASA TV on his TV system. I'm watching it now and they're going over this stuff. There's a press conference ongoing.

Beagle

[feidaykin]

First let me say I hope this problem is fixed. Next let me say even if it is not, Spirit has done some wonderful things already and that sure beats going boom before it ever lands like so many before it.

Now I'm going to say this: would all the people that bragged about NASA/JPL doing so much better than the Beagle team be quiet?

Guess what. Landing a complex machine on another planet is not easy. It's simply amazing humans can even do this at all. When something goes wrong, we can't exactly reach out and tap the little thing a few times to see if it fixes it.

The teams behind both Spirit and Beagle did excellent work against the insane list of Things That Can Go Wrong in getting something from here to there. Both teams did their best, and both teams make me feel very proud of the human race.

Re:Beagle

[barzok]

Now I'm going to say this: would all the people that bragged about NASA/JPL doing so much better than the Beagle team be quiet?

I have not been one of those people, but NASA/JPL still got the hardest part right - they successfully landed and operated the rover for a few days (and got good data back), rather than losing it entirely and never knowing what happened to it.

Touchdown is the most dangerous, hardest part of the operation to get right. Beagle didn't do that (we assume), Spirit did. Beagle got to the vicinity of the planet - but we've been successful many times in hurling an object at Mars and getting it in the neighborhood.

Re:Somewhere deep in the bowels of NASA

[dasmegabyte]

Or maybe there's one really paranoid engineer who complains about everything and, coincidentally, was right this one time.

Counterpoint

[Gorimek]

Some things get simpler with humans around, but many also get harder. Remember that manned missions to Mars cost something like 100 times more than unmanned. Measuring how much you get out of it per billion dollars is the interesting measure, not how much you get per mission.

Re:Java bot

[inertia187]

Yeah, that's funny. It may not be too far from the truth. the particular Java implementation they're using is realtime, so they can tune down or completely turn off garbage collection. Threads running with no interruption from garbage collection have a heap penalty, so they have to be really careful when to put a thread in that state.

IANAJPLR (I am not a JPL researcher) but I'm sure, however, there's a whole bunch of fail-safes that would kick in so that the worst case scenario is a loss of one day's worth of scientific data, if that.