Software Glitch Means Loss of NASA's Deep Impact Comet Probe

Taco Cowboy writes "'NASA is calling off attempts to find its Deep Impact comet probe after a suspected software glitch shut down radio communications in August, officials said on Friday.' Last month, engineers lost contact with Deep Impact and unsuccessfully tried to regain communications. The cause of the failure was unknown, but NASA suspects the spacecraft lost control, causing its antenna and solar panels to be pointed in the wrong direction. NASA had hoped Deep Impact would play a key role in observations of the approaching Comet ISON, a suspected first-time visitor to the inner solar system that was discovered in September 2012 by two Russian astronomers. The comet is heading toward a close encounter with the sun in November, a brush that it may not survive." Deep Impact has had a pretty good run, though: from its original mission to launch a copper slug at a comet (hence the name), to looking for Earth-sized planets.

Comments

Re: ALIENS

[tysonedwards]

Your explanation for anything slightly peculiar is aliens, isn't it? You lose your keys, it's aliens. A picture falls off the wall, it's aliens. That time we used up a whole bog roll in a day, you thought that was aliens as well.

A little more info from NASA

[g01d4]

After losing contact with the spacecraft last month, mission controllers spent several weeks trying to uplink commands to reactivate its onboard systems. Although the exact cause of the loss is not known, analysis has uncovered a potential problem with computer time tagging that could have led to loss of control for Deep Impact's orientation. That would then affect the positioning of its radio antennas, making communication difficult, as well as its solar arrays, which would in turn prevent the spacecraft from getting power and allow cold temperatures to ruin onboard equipment, essentially freezing its battery and propulsion systems.

Re:A little more info from NASA

[The Grim Reefer]

Although the exact cause of the loss is not known, analysis has uncovered a potential problem with computer time tagging

Upon further analysis it was discovered that while the hardware was designed to run on imperial hours, minutes, and seconds, the software was written using metric time.

Re:A little more info from NASA

[Shambhu]

Essentially, yes. National Geographic's piece had this quote:

"Basically, it was a Y2K problem, where some software didn't roll over the calendar date correctly," said A'Hearn. The spacecraft's fault-protection software (ironically enough) would have misread any date after August 11, 2013, he said, triggering an endless series of computer reboots aboard Deep Impact.

As far as I can tell the significance of that date is that it is approximately 2^32 tenths of a second into the millennium.

Poor NASA

[djupedal]

Can't find water, can't find methane, can't find their DICP - no wonder they have a hard time finding funding :)

Re: ALIENS

[Esion Modnar]

A roommate of mine in college had a religious poster stuck to the wall with yellow sticky tack. When it inevitably fell to the floor, he looked at where the picture had been, and said: "I rebuke you in the name of Jesus Christ, Satan." Yeah, it was Satan, not that unreliable sticky tack he used. Now, if it had crumpled itself up and flung over to the trash can...

Re:That's sad

[bmo]

I'm not a rocket engineer, and I can build a heliostat that tracks the sun with a couple of photodiodes and a long tube with a central divider, but something tells me that a spacecraft that far out might need something more accurate to, you know, not only see the Sun correctly, but actually aim the high-gain antenna at Earth instead of a point halfway between the us and the Moon.

--
BMO

Re: ALIENS

[thoughtspace]

Finally WE get to probe the aliens.
Send Deep Impact's sister probe: Deep Throat.

Re:*inhales*

[NotQuiteReal]

You are paranoid. There is no way a computer can tell how many CAPS you are taking.

the spacecraft may still be alive

[John_Sauter]

It is possible that the spacecraft is going through layers of falesafes, until it finally just points its solar panels at the Sun, points its radio antenna at Earth, and cries for help. Remember the mission to Eros: http://klabs.org/richcontent/Reports/Failure_Reports/NEAR_Rendezvous_Burn.pdf

Re: ALIENS

[FatdogHaiku]

That can all be explained without extra-planetary influence...
You lose your keys, it's aliens.
No, that's gremlins.
A picture falls off the wall, it's aliens.
Sorry, that's poltergeists.
That time we used up a whole bog roll in a day, you thought that was aliens as well.
In the USA we normally attribute that to Taco Bell.

Indeed, it needs a bit more

[dutchwhizzman]

In fact, it needs equipment that can take extreme radiation and hits from dust particles travelling at 10000 km/h and faster. The parts you would use on earth wouldn't last a year in space, probably more like a week. The initial design called for a way shorter life time than they got out of it, so parts failure to sensors or other electronics due to impact or radiation is a likely cause. Try running a car without maintenance for 5 years. You may get lucky and still be driving, but chances are extremely small. This mission was similar to that.

Re:Hmmm

[symbolset]

The peril of human controlled computer operated machines is that they do what you told them to do, whether or not what you said was what you intended.

Re:That's sad

[Yoda222]

I'm not a rocket engineer (never done rockets, I'm more in satellites) but I guess that the antenna are trying to point toward the third planet around this brightest star, not the star itself.

And I would say that it's easier to implement a robust (with respect to sensor/actuator failure) pointing system with software than with analog hardware. But that's just a guess, feel free to propose me a good hardware design for that. (in fact that's not true for everything, you can have a gravity gradient stabilisation with no software at all, and spin stabilisation, but you still need software to change/control the spin axis)

Thanks, NSA

[roscocoltran]

This time I think you hacked a bridge too far.

Re: your sig

[wonkey_monkey]

Apologies on the pedantism.

You mean pedantry.

Re: ALIENS

[Impy the Impiuos Imp]

Cut him some slack on the exorcism -- after all, you guys are surrounded by fellow students whose heads are constantly spinning and vomiting and swearing like a sailor.