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Hubble Telescope Hit By Mechanical Failure (bbc.com)
The Hubble Space Telescope is operating with only essential functions after it lost one of the gyroscopes needed to point the spacecraft. From a report: The observatory, described as one of the most important scientific instruments ever created, was placed in "safe mode" over the weekend, while scientists try to fix the problem. Hubble had been operating with four of its six gyroscopes when one of them failed on Friday. The telescope was launched in 1990. After the gyro failure at the weekend, controllers tried to switch on a different one, but that was found to be malfunctioning. That leaves Hubble with only two fully functional gyros. At any given time, Hubble needs three of its gyroscopes to work for optimal efficiency.
It's flat, not planar you clod. There is a bottom. That's where the little people live.
A service call to Hubble is out of scope for the first several SpaceX manned launches. It doesn't provide the same capabilities as the Shuttle at all.
But Elon might actually offer a solution, or at least offer to offer one.
deleting the extra space after periods so i can stay relevant, yeah.
Do we really need Hubble that badly anymore?
Apparently adaptive optics technology is allowing ground-based telescopes to surpass Hubble's capability.
https://www.airspacemag.com/sp...
Rather than firing up an expensive space mission (I remember each shuttle mission was $500M), would it genuinely be better to just take that money and build or retrofit a ground-based telescope with adaptive optics? A telescope that you could easily maintain thereafter?
This doesn't help with wavelengths of light that don't go through Earth's atmosphere, but that's not what Hubble does. Seems like we could do without Hubble nowadays.
--PeterM
I thought that's where the turtles are.
But Elon might actually offer a solution, or at least offer to offer one.
I've heard that he has a spare one-man capsule that was designed specifically for rescue missions.
The Earth is flat. You only need 2 gyros to point oneself in 2D space.
That's true but they need 3 because the telescope can rotate, which messes with the image. There's X, Y, and rotation, that need to be controlled for. They can operate with a single gyro but that means they can't stop rotations, and in fact use the rotation to their advantage to reposition the gyro for controlling X and Y alternately as rotation puts the gyro in the proper plane. Hubble launched with 4 gyros, meaning it had a spare from the start. With the first gyro failure they simply lost the spare. With the second failure they lost the ability to control rotation and/or ability to position with as much speed and accuracy. Going down to one means they can still move but very very slowly.
I am armed because I am free. I am free because I am armed.
Doing another maintenance run on the Hubble is probably beyond the spec/capabilities of the first manned SpaceX launch, currently planned for mid 2019.
I fear you are correct. Hubble was/is at the extreme limits of the shuttle system's ability and the last trip was risky enough that they almost didn't do it. Now we have no shuttle.
I don't doubt Space X could engineer some solution to service Hubble, but the timeframe it would take to develop the capability is likely to be longer than the scheduled replacement's arrival. To do this Hubble service thing, you need to first catch it in orbit (the shuttle used an astronaut on the robot arm for this) so you can work on it, then open it up and move around some large chunks of delicate gear from some kind of cargo area.
Given the age of Hubble, the cost of such a rescue mission and the projected replacement of the system already scheduled, I'm guessing they use Hubble as best they can with what's left that is still working. It's been a great achievement, but I don't think it's worth it at this point to try and fix the thing. Besides, we all knew the day would come when Hubble would work no more. It's sad, but the time may be closer than we would like to admit.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
If you are trying to refute the GP, you are doing so very, very badly. The G.P. is correct, and nothing you said actually contradicts him. The only thing he said incorrectly was that the craft will orbit the point - it doesn't, it orbits the sun, but it does move around the Lagrange point in a semi-stable manner.
Orbits are, *of course* curves described by parameters. It so happens that in the co-ordinate system centered on the Lagrange point, and aligned to the sun, that the movement of spacecraft around the Lagrange point is, in fact, described by a Lissajou curve.
Since this isn't a scientific paper, I'll direct the curious here:
That wiki thing
It's even worse than that. JWST isn't a real REPLACEMENT for Hubble. It'll be able to do things that Hubble can't, but there are even MORE things Hubble can do that JWST won't ever be able to do.
The fact is, we don't have the ability to launch a new satellite as big or as heavy as Hubble... and AFAIK, there are no rockets even under development that will be capable of delivering something as physically BIG as Hubble (or the existing ISS modules) into orbit. Hubble and the existing ISS modules are all we have, and all we're LIKELY to have for DECADES. They're literally irreplaceable within the span of our lives, and as such, deorbiting them is, IMHO, wantonly reckless and irresponsible. If Hubble's telescope functionality dies before we have the ability to send a refurbishment mission, we should be ready to DO the deorbiting mission on 18 months' notice... but always and only as a last-ditch "plan B" if we don't get the ability to launch a robotic or manned servicing & refurbishment mission first.
From what I understand, if Hubble failed completely and became totally uncontrolled tomorrow, it would be at least a decade before it fell far enough to present imminent risk of uncontrolled reentry. If we made even a token attempt to send a robotic mission to boost it into a higher orbit, we could easily add another decade to that. SpaceX might not be ready to fly a refurbishment mission to Hubble within the next 3-5 years... but it probably COULD be ready to do it 6-10 years from now (if it had a firm commitment from NASA), and will probably be capable of doing it within 10-15 years regardless of what NASA does (and knowing Musk, would probably invoke maritime salvage law & refurbish Hubble ITSELF as a commercial venture if NASA couldn't/wouldn't do it).
Frankly, I think 90% of NASA's sense of deorbiting-urgency is precisely BECAUSE they'd rather see things like the ISS and Hubble get intentionally destroyed than risk allowing someone else to metaphorically grab them from the curb before the garbage truck arrives.
A service call to Hubble is out of scope
Hubble had Servicing Missions in 1993, 1997, 1999, 2002, and 2009.
The 1999 and 2009 missions replaced the gyroscopes. So this was expected.
The Hubble was being built around the time the Commodore VIC20 and Sinclair ZX80 were released, though the launch was long delayed.
So maybe it is time to retire it. Perhaps a small ceremony and fireworks display over the South Pacific.