From UPI and NASA Watch NASA may crash science satellite Friday, 14 January 2000 19:55 (ET)

WASHINGTON, Jan. 14 (UPI) -- NASA is quietly preparing to crash one of its most expensive and productive space satellites back to Earth, perhaps as early as March. It will be aimed to fall into the Pacific Ocean far from land

The deliberate destruction of the billion-dollar Compton "Gamma Ray Observatory" is considered the only alternative to letting it fall to Earth at random. The 17-ton satellite is given a frightening one-in-a-thousand chance of causing a "human casualty" in such an uncontrolled descent

As recently as last fall, ground controllers assessed the spacecraft as healthy. Its remaining lifetime was estimated as "another 8-10 years."

NASA had recently completed an upgrade to the satellite's ground control center.

However, on Dec. 6, one of the spacecraft's three gyroscopes broke. Thesespinning sensors are used to point the satellite in space. Although it still can point accurately with the remaining two gyroscopes, the loss of another one of them would leave the spacecraft without the ability to know which way it was facing in space. This would make scientific observations worthless, and would also make the controlled descent impossible.

Links to the story:

UPI Version

http://www.spaceref.com/news/viewnews.html?id=64

NASA Watch Version

http://www.spaceref.com/news/viewnews.html?id=64

-- Carl Jenkins (Somewherepress@aol.com), January 15, 2000

Answers

Wait. This kind of stuff is being hidden from the general public. Why would they release this information? It must be Y2k related.

Establish the tie.

Accountability. Substantiation. Prove it. Show me the money.

-- nomobs (proof@accountability.com), January 15, 2000.

Gyros are expensive and tricky little bastards, from my limited non- technical contact with them.

I remember when I worked for a small defense contractor for a while (we made reconnaissance drones) and I took a Fedex delivery of a small box of 6 or so gyros, worth about $30,000 total, I think:-). Never had I held so much $$$ in my hands...

The vast majority of the work in those constant Hubble repair flights is replacing gyros, best I can tell..

For whatever reason, hard to keep them going in space.

Frankly, I'm surprised the thing was launched with so few gyros. Seems to be a design flaw to me, should have had 5 of them.

Given the size of the thing, an awful lot of it would survive a re-

-- John H Krempasky (johnk@dmv.com), January 15, 2000.

A design flaw!!!! John! Not a Y2K design flaw -- only two digit date-field -- but an "only 3 gyros" design flaw! They sent the space shuttle up to replace the failed gyroscopes. What happened? Di dthe replacements also fail? Is it cheaper to scrub the whole multi- billion daoolar craft, of ssend up another space shuttle ?

-- Squirrel Hunter (nuts@upina.tree), January 15, 2000.

Well, the thing was designed before the Challenger accident...

One thing to keep in mind is that NASA back in the early 80s had wild fantasies of exactly how many Shuttle missions they'd be flying a year...many, many times what they've actually been able to fly.

It's turned out that turn-around will always take much longer than they thought and they simply don't have the money.

So I think they assumed that there would be so many missions that repair would be no big deal. Unfortunately, this has turned out not to be the case.

-- John H Krempasky (johnk@dmv.com), January 16, 2000.