The Space Shuttle has bad clocks?

[retire@40]

I had to read this one a couple of times, but this is what they are reporting:

NASA wants Discovery back from its 12-day mission by New Year's Eve because shuttle computers are not designed to make the change from the 365th day of the old year to the first day of the new year while in flight. The agency has developed a fix, but would prefer not to try it.

http://news.yahoo.com/s/ap/20061209/...ace_shuttle_95

My $40 Casio wristwatch can do this and the space shuttle computers can't

[Nords]

Quote:

Originally Posted by retire@40 My $40 Casio wristwatch can do this and the space shuttle computers can't

Was your watch built by the lowest bidder on a govt contract?

With apologies to UncleMick, who I'm sure didn't work on this particular part of the software...

[gindie]

Quote:

Originally Posted by Nords Was your watch built by the lowest bidder on a govt contract? With apologies to UncleMick, who I'm sure didn't work on this particular part of the software...

Nords, as a 23-year government contractor software developer myself, I can only guess that since "the shuttle computers are not designed to make the change", the custiomer (NASA) did not put this into the requirements.

[dmpi]

Quote:

Originally Posted by retire@40 I had to read this one a couple of times, but this is what they are reporting: NASA wants Discovery back from its 12-day mission by New Year's Eve because shuttle computers are not designed to make the change from the 365th day of the old year to the first day of the new year while in flight. The agency has developed a fix, but would prefer not to try it. http://news.yahoo.com/s/ap/20061209/...ace_shuttle_95 My $40 Casio wristwatch can do this and the space shuttle computers can't

mission_completion = current_mission_time - mission_start ;
if ( mission_completion >= DAY_11 ) land_shuttle() ;
else keep_flying() ;

......

[Nords]

Quote:

Originally Posted by gindie Nords, as a 23-year government contractor software developer myself, I can only guess that since "the shuttle computers are not designed to make the change", the custiomer (NASA) did not put this into the requirements.

If I had a nickel for every time I've heard "Sorry, can't do it, it's not part of the ship's design configuration control..."

[TromboneAl]

Score:

Y2.007K 1
Rocket Scientists 0

[rs0460a]

So they come back on December 42'nd - What's the problem ...

- Ron

[2B]

The shuttle still uses 8088 processors ala the mid-1980's when they were built. Nothing gets changed that isn't "space proven." If you can't use it in space, it gets real tough to get something "space proven."

I've been in the mock ups that are used for training. Everything is supposed to work exactly like the fully operational shuttles. They are basically old, outdated and past obsolete. If we're going to keep going up, we need some new stuff.

I will agree with the comment about "if it wasn't in the spec it isn't in the software." That was gospel. Never do anything that isn't in the contract. If that had been programmed in, some COTR would have "dinged" the contractor for doing it.

[TromboneAl]

Related to this: It's amazing how much time and effort I wasted, writing and supporting my time and billing application, dealing with different date and time formats and especially daylight savings time changes.

For a few years, every time there was a switch between daylight and standard time, I'd get a few calls from places like Lithuania or Indianna that had non-standard switchovers.

Humans are really bad at choosing standards and sticking to them. Can't even have a single standard for what time it is.

IIRC, Two of NASA's most public failures were due in part to multiple standards. Apollo 11, voltage standards different; Mars mission Metric vs. English system.

[riskadverse]

For years and years I made early morning trips to "bounce" mainframe computers to reset the clock. NASA used the same types of mainframes, so I'm sure they have lots of experence with these issues.