Final Repair Mission To Extend Hubble's Life

necro81 writes "The NYTimes has an in-depth piece describing an upcoming shuttle mission, scheduled for next August, to make a final service call to the Hubble Space Telescope. After the Columbia accident and the scheduled shuttle decommission in 2010, additional service trips to the telescope were off the table. The resulting hue and cry from scientists, legislators, and the public forced NASA to reconsider. Next August, if all goes well, Atlantis will grab Hubble, replace its aging gyros, attempt to revive the Advanced Camera for Surveys, and install a new camera and spectrograph. The telescope could then continue doing science well into the next decade."

Re:Other than the Apollo missions...

[filterban]

Yes, there was a flaw in the mirror. I remember the size of the flaw being described at a space museum tour as:

"Take one strand of your hair. Cut it lengthwise 36 times; take one of those strands and cut it another 36 times lengthwise."

To me, that just underscores the difficulty in putting a telescope in space. True, the flaw was considered a debacle, but NASA fixed it by correcting the instruments on the telescope by an equally offsetting amount. This has led to amazing discoveries and the Hubble can largely be viewed as a success.

In my mind, it's a shame that we won't be keeping it running past 2013.

Advantages of Hubble still worth it?

[joshamania]

Are the advantages of having Hubble outside the atmosphere still worth the expense? I'd rather see NASA spending their money on Mars.

I thought I had heard that new ground-based telescope technology has largely made the benefits of the old Hubble obsolete. Does anyone know anything more specific on that?

Re:No way

[dgatwood]

True, but I would argue that Hubble and the Mars rovers have done far more to promote space science to the masses. In an era where scientific research is often the first thing on the chopping block, the importance of projects like Hubble should not be underestimated.

Re:Advantages of Hubble still worth it?

[Shooter6947]

However you may have a point about the cost/benefit ratio. For the price of a shuttle launch to repair Hubble (~$1B), you could just about build and launch a new one on an unmanned rocket. If there were a concerted program to launch a virtually identical 2-meter telescope every 4 years with different instrumentation on it, that program would be better and cheaper than continuing to repair Hubble. However, congressional whims being what they are, such a program would inevitably get cut after its first mission, obviating the savings. Hence NASA has opted to continue to repair and update Hubble instead.

Will it really be the last trip?

[xlation]

IIRC we cannot, by treaty, just let the Hubble's orbit decay like Skylab & Mir, we need to do a de-orbit burn and drop it in the Pacific, or some other relatively safe place. The problem was this, is that the Hubble has no rocket engines on board, so we need to send something up there to attach an engine.

That would be a complicated robotic mission, but there is a further complication... Once enough gyros fail, it will start to tumble. That would make a servicing mission near impossible. (you could no longer just grab it.)

So once NASA decides that we need to go anyway, why bother to de-orbit it? Servicing Mission 3B was in 2002, if they can get another 6 years out of SM4 that will get them to 2014. If NASA is serious about replacing the shuttle, they should be able to get another manned craft into low-earth orbit by then, even if it is using an off-the-shelf launch system,

Sure brings

[aengblom]

"The Device NASA Is Leaving Behind" [slashdot.org] into context. (It being the last Slashdot story in the Space section.)

Re:Other than the Apollo missions...

[DerekLyons]

That, and when they fixed the lens they also replaced all of the on-board electronics, because JPL and NASA had consumed too much of the component life before the satellite was even launched into space.

Except - they didn't replace all the on-board electronics when they installed the fix for the mirror. (Hubble's problem was a flawed mirror - not a flawed lens.)
 
 

Hint: if you want to lifetime test a part to make sure it's reliable, don't use that part in your satellite after burning up its usable life. Buy two parts from the same batch, test one, and use the other one.

Hint: NASA and JPL know that. You don't seem to know much of anything, since both of the 'facts' in your introductory statement are actually 'fantasies'.

Mixed feelings

[FridayBob]

While I'm glad that the Hubble is going to be repaired, after reading yesterday's article [slashdot.org] about the Alpha Magnetic Spectrometer (AMS) [washingtonpost.com] that looks like it won't get delivered to the ISS due to a lack of available shuttle missions, I'm no longer sure it's the right thing to do. Seeing as the AMS took 500 physicists 12 years to build and cost $1.5 billion, and that it's capable of doing new and amazing science, I think it deserves a chance. The Hubble has already been up their for years and will be replaced in 2013 by the James Webb Space Telescope [wikipedia.org] anyway. The AMS has no replacement; not launching it would be worse than not repairing Hubble.

Re:Mixed feelings

[Dr. Evil]

OMG. 500 Physicists, 12 years of work, 1.5 Billion? I'm outraged! The biggest boondoggle in the history of the ISS could have paid for an extra week of war in Iraq!

Why are the gyros failing?

[ChrisMaple]

It's been more than 20 years since I was in the inertial navigation business, but my recollection is that there should be no significant wearout mechanism for gyros. Mechanical gyros use air bearings (or possibly magnetic bearings): no contact, no wear. I suppose if they're using laser gyros they'll fail eventually due to problems with impurities or thermal stresses or something.

Are the control electronics associated with the gyros failing? What gyro technology are they using?

Part of the ISS?

[yuriyg]

This might sound naive, but what about attaching this thing to the ISS? Sure would make maintenance a lot more easier, with all those regular flights and round-the-clock human presence.

Is there anything fundamentally incompatible with the design of the Hubble and the ISS? (orbit, need to rotate, etc.?)

Re:Other than the Apollo missions...

[Sanat]

"That's a pretty poor debacle compared to, say installing an accelerometer upside down"

We fired a missile out of Vandenburg a few years ago that had the angular accelerometer wires color coded backwards. The test coil was wired correctly so all diagnostics passed.

When the missile was fired and cleared the underground silo it was normal for the missile to pitch towards 70 degrees. As it approached that angle the the speed of pitching is reduced to zero, however if the accelerometer is reverse wired then the missile pitches faster instead of slower and the missile simply cleared the silo wall and pitched level to the ground shooting across the fields at what seemed to be a thousand miles an hour and it started a couple of fires and also caused a lot of scrambling of onlookers until the range officer was able to destruct it.

We were out with our field jackets extinguishing the fires and then had to pick up all of the unburned propellant (green solid fuel).

Of course, we kept some propellant back and would ignited it in ashtrays and stuff like that as practical jokes. I wonder how I survived some of the stuff I was involved with in those days.