Costs of the robotic Hubble repair mission have been skyrocketing.

The estimated price tag of a robotic rescue mission -- between $1 billion and $2 billion -- is raising eyebrows and questions about whether Hubble is worth the investment amid tight budgets and periodic reports of technical woes that could cripple the spacecraft before the robot gets there.

I've never taken this mission seriously. I don't think that NASA ever really intended to do it. The initial studies were just a fig leaf to distract attention from the fact that they weren't willing to send a Shuttle to it, and assuage Hubble fans. The problem that they have now is that just safely deorbiting the thing is going to be impossible to do for a reasonable amount of money. I still think they should do the Shuttle servicing mission, because the marginal cost of that is the absolute cheapest thing they can do, and the risk is overblown (though even if it's as dangerous as some think, it's still one of the few things that Shuttle could do that would actually be useful).

By the way, they (like almost everyone) gets this part wrong:

If the cost hits $2 billion, that's three to four times what it would cost to send astronauts to do the job as they have four times before and as NASA planned before the Columbia disaster.

That's not what it would cost to send the Shuttle. The marginal cost of a Shuttle flight is somewhere between a hundred and hundred fifty million dollars. They're basing this assessment on the average cost, which is more than half a billion, but that's not the number one would properly use to make that decision.

I like the suggestion that someone had about building a Hubble II using the backup mirror. Launching that on a Delta IV/Atlas V/Ariane V to the L2 point would probably cost as much as a servicing but you would get a brand new telescope in a better location.

...to the L2 point...

Ignoring all the other issues related to different design requirements for that location, how would you get the data from it? The moon makes a much better door than it does a window...

L2 is also unstable, and will need fuel to stay in place. Why not the stable co-orbital points (L4, L5) if that's your goal? Then again, why not just an orbit between the current low ceiling of the shuttle and geosynchronous? That gets you a few thousand years without a reboost.

The real solution is for NASA to show some guts— time the service mission such that an ISS flight a few weeks later could be used as a rescue instead, and then spend some of the first EVA time for a safety check . At that point, it won't be any more hazardous than an ISS flight. (You could add extra oxygen tanks and supplies for the contingency rescue wait if that makes you feel better, too.)

That NASA doesn't consider this a viable option is an indication of how timid an organization it has become.

Oh you know there are some people in NASA that keep touting the, "but NASA is supposed to use space to develop technology." Then, believe that this is a great oppurtunity to use the Bobba Fett looking space robot they've been tinkering with.

Seems strange though that they wan't to go for a such an ambitious project whenever we are incapable of getting the DART autonomous rendezvous craft launched to perform a robotic docking simulation of which the Russian's have been capable of performing for several decades now.

I think one of the biggest problems with Hubble is that observation time is such a precious commodity. The astronomical community would be much better served with a fleet of space based telescopes ranging from suitcase to small compact car sizes. Lets save the next big space based telescope project for the James Webb.

I worked on HST for 10 years, and I agree with Rand that the robotic servicing mission was/is not feasible. The irony is that NASA will have to find a way to get it back to Earth safely (probably using Shuttle/Shuttle replacement).

The Science community is a very powerful lobby and does not want to lose HST functionality. It will be interesting to see if they can overcome the hysteria regarding Shuttle launches and get a real servicing mission.

why not just an orbit between the current low ceiling of the shuttle and geosynchronous?

That's right in the radiation belts. Not only would it degrade the PV arrays and other electronics, it would also add lots of noise to the detectors.

Just wild speculation, but how about a serious _lunar_ telescope? If we're really going there first, what kind a of telescope would that allow?

"though even if it's as dangerous as some think, it's still one of the few things that Shuttle could do that would actually be useful"

Actually, you'll run into some chicken and egg PR on that...

STS needs HST needs STS
or
STS needs ISS needs STS
add Raoul Ortega and you get
HST needs STS needs ISS needs STS

No wonder the NASA civil servants feel safe in their jobs.