Hubble servicing missions cancelled - Page 6

The Bad Astronomer · #**151** (**permalink**) 31-August-2005, 09:58 PM

Quote:

Originally Posted by publiusr

Hubble will be safe--and with us for quite some time now.

I wish that were true, but it may not be.

Hubble will stay on orbit for longer than expected, which is great. However, the gyros are failing. If they lose control of the observatory due to a gyro failure, it will stay in orbit, but tumble. In that case, neither machine nor man will be able to fix it, since it's unsafe to approach a tumbling spacecraft.

So the time limit is not the orbital degradation, but the mean time between gyro failures.

The Bad Astronomer · #**152** (**permalink**) 31-August-2005, 10:05 PM

Cripes, speak of the devil:

Hubble starts two-gyro operation:

Quote:

NASA's Hubble Space Telescope entered a new era of science operations this week, when engineers shut down one of the three operational gyroscopes aboard the observatory. The two-gyro mode is expected to preserve the operating life of the third gyro and extend Hubble's science observations through mid-2008, an eight-month extension.

George · #**153** (**permalink**) 31-August-2005, 10:35 PM

Quote:

Originally Posted by The Bad Astronomer

Cripes, speak of the devil:

Hubble starts two-gyro operation:

Quote:

NASA's Hubble Space Telescope entered a new era of science operations this week, when engineers shut down one of the three operational gyroscopes aboard the observatory. The two-gyro mode is expected to preserve the operating life of the third gyro and extend Hubble's science observations through mid-2008, an eight-month extension.

I was just googling for the two gyro story.

Quote:

Originally Posted by article

The system was originally designed to operate on three gyros, with another three in reserve. Two of the six are no longer functional.

So, four are functional, of which two are operating.
I enjoyed the February article .

Quote:

"When the engineers started writing the software, they had grave doubts," says Edward Weiler, director of NASA's Goddard Space Flight Center in Greenbelt, Maryland, US. "But I just got a report the test worked so well it's almost embarrassing. It's a real success story."

All good news. =D>

tracer · #**154** (**permalink**) 01-September-2005, 02:03 AM

Quote:

Originally Posted by The Bad Astronomer

If they lose control of the observatory due to a gyro failure, it will stay in orbit, but tumble. In that case, neither machine nor man will be able to fix it, since it's unsafe to approach a tumbling spacecraft.

Insert Russian-space-station-in-Armageddon joke here.

publiusr · #**155** (**permalink**) 07-September-2005, 06:13 PM

Quote:

Originally Posted by The Bad Astronomer

I wish that were true, but it may not be.

Hubble will stay on orbit for longer than expected, which is great. However, the gyros are failing. If they lose control of the observatory due to a gyro failure, it will stay in orbit, but tumble. In that case, neither machine nor man will be able to fix it, since it's unsafe to approach a tumbling spacecraft.

So the time limit is not the orbital degradation, but the mean time between gyro failures.

When I first wrote my post--we didn't have a $100 billion disaster estimate and a manned repair mission seemed very near.

If someone even mentions space spending now critics will descend upon them like harpies.

It has to be done under the table in some way.

ToSeek · #**156** (**permalink**) 14-September-2005, 07:40 PM

Health Checkup: Engineers Work to Stall Hubble's Death

Quote:

To keep the Hubble Space Telescope going, officials are changing how it operates and contemplating other actions for the aging observatory.

Engineers recently shut down one of the orbiting observatory’s three operational gyroscopes in an effort to preserve the operating life of the third gyro, thereby pushing Hubble’s science observations into mid-2008.

Other life-extension ideas are being studied – even downshifting Hubble onto one-gyro mode.

Scientists and engineers remain hopeful that the telescope will once again get a servicing makeover by astronauts. But such a shuttle mission depends on the health of that human spaceflight program. The shuttle is headed for retirement in 2010, with a vaguely defined Crew Exploration Vehicle to be its replacement. Meanwhile, it is not clear when the next flight will take place nor whether a trip to Hubble will be possible.

Keeping Hubble alive and scientifically valuable has become a race against the clock that involves aging hardware and dwindling battery life while solar activity that eats away at satellite’s orbit -- and of course, budget considerations.

jt-3d · #**157** (**permalink**) 14-September-2005, 08:54 PM

Sounds like the desperate to keep a dying patient alive, which I guess it is. So sad.

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