Hypothetical Hubble Rescue

[PB666]

39 minutes ago, Tex_NL said:

So you're suggesting to send up an new telescope, everything except the mirror. And then place Hubble's mirror in that new telescope.
Doing this you will indeed save weight and money by not launching the mirror. But you will need some very sophisticated equipment or a long EVA (most likely both) to move the mirror. The resources required for this will be more that the weight and money saved by not launching a mirror in the first place.
It's not worth it.

If that were the case NASA would have replaced thier mirror in the first salvage. 

[Tex_NL]

9 hours ago, PB666 said:

If that were the case NASA would have replaced thier mirror in the first salvage. 

Next time please don't quote me if you want to reply to @cantab.

[PB666]

2 hours ago, Tex_NL said:

Next time please don't quote me if you want to reply to @cantab.

Was responding to you, not him. And thread itself is pretty idiotic, sooooo. 

[Camacha]

On 10/05/2016 at 10:00 AM, Steel said:

Also even if you did manage to de-orbit the Hubble with a heat shield, I very much doubt it was built to survive a 9-12 g ballistic re-entry

It was built to survive an equally violent ascent, for the most part.

[kerbiloid]

They should dock the Hubble to ISS, allowing them to share their common fate.
So, instead of two tragedies, there would be an opera, "Twilight of the Gods".

[Tex_NL]

On 26-6-2016 at 11:30 AM, PB666 said:

Was responding to you, not him. And thread itself is pretty idiotic, sooooo. 

In that case you should go back and actually READ what I said. I said any replacement mission would NOT be worth it.

[cantab]

4 hours ago, kerbiloid said:

They should dock the Hubble to ISS, allowing them to share their common fate.
So, instead of two tragedies, there would be an opera, "Twilight of the Gods".

Unfortunately Hubble and ISS are at different inclinations so the delta-V requirements are prohibitively great. The Hubble was launched into an orbit convenient for Space Shuttle servicing missions, but the ISS was put in a more inclined orbit so that Russian rockets launched from Baikonur can reasonably reach it.

If they had been in the same inclination, then that would have provided a way to continue Hubble servicing missions after the Shuttle retirement - add suitable spacecraft parts to the Hubble, then have it rendezvous with the ISS and be grabbed by the Candarm 2. The ISS is capable of supporting the complex EVAs required. Then let Hubble go afterwards because the vibration on the space station would muck up its images.

But alas, history went a different way.

[wumpus]

On 6/25/2016 at 5:36 PM, PB666 said:

If that were the case NASA would have replaced thier mirror in the first salvage. 

That assumes that the astronauts could get at the thing, remove the old one, and replace the new one.  They had enough trouble replacing parts that were more or less designed to be removed (and maintained).  That ignores that the whole structure exists to carefully maintain alignment between the mirror and the secondary lens.  I'd be fairly shocked if an astronaut could get it out during a spacewalk.

There is also the *time*, but that doesn't appear to be as bad as I expected (I've heard of years to polish smaller mirrors than that, but without a NASA budget).  On the other hand, they had a backup mirror.  It was only a few nm off in the center, and presumably could be fixed by a few rounds of polishing (to even everything up to parabolic).  I'm guessing nobody thought they could get the mirror out.

[PB666]

1 minute ago, wumpus said:

That assumes that the astronauts could get at the thing, remove the old one, and replace the new one.  They had enough trouble replacing parts that were more or less designed to be removed (and maintained).  That ignores that the whole structure exists to carefully maintain alignment between the mirror and the secondary lens.  I'd be fairly shocked if an astronaut could get it out during a spacewalk.

There is also the *time*, but that doesn't appear to be as bad as I expected (I've heard of years to polish smaller mirrors than that, but without a NASA budget).  On the other hand, they had a backup mirror.  It was only a few nm off in the center, and presumably could be fixed by a few rounds of polishing (to even everything up to parabolic).  I'm guessing nobody thought they could get the mirror out.

But they would not do it now, the best they can do it replace the panels and batteries and gyroscopes.

[Rakaydos]

Hubble will not be taken down until it is irreviviably dead. A micrometeor strike on the mirror, say.

However, as this topic is a hypothetical, lets say that happened, sometime after 2025. The smithsonian wouldnt care what condition it was left in if  they could retrieve enough pieces to say they have the actual Hubble Telescope. The only super-heavy payload lander currently in the works right now is being designed for SpaceXs mars ambitions... but if Elon's tweets are to be taken as gospel it should be in the right payload range to recover hubble and land it in... well, as many pieces as they found it in.

It's totally not what the BFS is designed for, but SpaceX is all about multipurpose hardware. Falcon 1 Merlin being used as both lift and vacume engin for the falcon 9, Crew Dragon being designed with Red Dragon Conversion in mind- even interview responces to the tune of "well, the hardware s designed for mars, but if someone paid us we could totally land on tthe moon with it, because mars is harder."

There may be other options by then, depending on how long we can keep  patching hubble back together before something happens we cant patch. There could be a 1-use custom designed reentry shield lofted by ULA, or Blue Origin may be in the orbital market by then- or russia could dust off their own shuttles. But spaceX already has plans to build hardware capale of managing the task... and plan to keep building the hardware, in pursuit of their founder's personal dream. Therefre I find it likely that BFS or a successor design will still be in operation when lady luck catches up with hubble.
 

 

Edited June 27, 2016 by Rakaydos

[wumpus]

27 minutes ago, Rakaydos said:

Hubble will not be taken down until it is irreviviably dead. A micrometeor strike on the mirror, say.

Judging by how other telescopes have died, I'd expect the last gyroscope to go first.  And then NASA will have to deorbit it.  The only other long-term place is the "graveyard orbit" out near GSO, and that might as well be interstellar by the delta-v requirement.

[Bill Phil]

31 minutes ago, wumpus said:

Judging by how other telescopes have died, I'd expect the last gyroscope to go first.  And then NASA will have to deorbit it.  The only other long-term place is the "graveyard orbit" out near GSO, and that might as well be interstellar by the delta-v requirement.

Deorbiting would be impossible* as well, unless they let it naturally decay.

*no hardware for it

[PB666]

50 minutes ago, Bill Phil said:

Deorbiting would be impossible* as well, unless they let it naturally decay.

*no hardware for it

They place an adapter on it they could use to grab onto and change the perigee. 

[Bill Phil]

6 minutes ago, PB666 said:

They place an adapter on it they could use to grab onto and change the perigee. 

That would take a while to engineer.

[PB666]

8 minutes ago, Bill Phil said:

That would take a while to engineer.

Its already attached, but if lost its gyro it might not be usable

[kerbiloid]

They could test the Orion's asteroid reorbiting mission with Hubble.

[JetJaguar]

FWIW, there is a practical reason for returning the HST to Earth that I can think of.  As an engineer, I would love to have the opportunity to do a teardown inspection of a satellite that's been operational for decades.  I still think a retrieval mission would be too expensive even for that, though.  It's value as a scientific instrument is such that we should just keep servicing it for as long as we can keep it going.  I don't think there's any reason that has to be done with a Shuttle, an Orion-based mission would probably be possible.

[wumpus]

1 hour ago, JetJaguar said:

FWIW, there is a practical reason for returning the HST to Earth that I can think of.  As an engineer, I would love to have the opportunity to do a teardown inspection of a satellite that's been operational for decades.  I still think a retrieval mission would be too expensive even for that, though.  It's value as a scientific instrument is such that we should just keep servicing it for as long as we can keep it going.  I don't think there's any reason that has to be done with a Shuttle, an Orion-based mission would probably be possible.

I can't imagine the issues in retrieving it.  Maybe if NASA wants to do another test with an inflatable heat shield they could use the HST as ballast for the way down.  The next closest mission I can think of would be mining experiments, but I'd assume that any mining returns would be wildly more compact (basically a huge ingot, or possibly shaped ore) and then use litho/hydrobraking.  I can't see anyone funding that (the inflatable heat shield is remotely possible, but would have to already be almost ready to go when the gyroscopes failed.  So don't really think it could happen).

If you just want parts that have been in space that long, wait a bit longer for ISS replacement parts (because it hasn't been up as long) and examine them (assuming they went down safely).  Of course, these were in a much more benign environment, but I'd expect plenty of parts on the outside to keep the whole thing going, and they will probably need replacement more often.  Finally, I'm pretty sure that quite a few parts were replaced and came back from HST on the Shuttle's last mission there to refurbish it.  They should still exist (and have already been examined, I hope).