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Hubble Verdict: De-Orbit
theonetruekeebler writes "CNN reports that NASA has reached a final decision for the Hubble space telescope: De-orbit. At some future date a liquid-fueled rocket will dock with the telescope and fire, hurling Hubble into the ocean. However, "Our best estimate is we probably will be able to continue to do science as we're doing it ... somewhere into 2008," according to program executive Mark Borkowski."
Hubble is meant to run mainly off solar power. Shooting it out of the solar system would make it useless after it got a short distance from the sun. Its communication system is not made to broadcast very far, and giving it a high velocity would drastically decrease its ability to take clear pictures. Also, it isn't really made for "extra-terrestrial contact". It doesn't have any greeting plaque, just some dirty pictures written on it by astronauts and the various labels and warnings on the parts.
Fact is its not better anymore. At least in the visible range the VLTI is better.
But of course there is no alternative to a space based telescopy in the UV and IR (which is now done by the pfitser), but the main problem is that keeping it up there isnt the problem, but the fact that its getting OLD. Nearly everything needs an overhaul.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
It's not just getting old, it's getting BROKE. After about 2008, it's going to be useless. It won't be able to aim at anything because of the failing gyroscopes. We don't want that in orbit for even longer, we want it de-orbited.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
Actually this is a very common misconception.
Any satellite in a stable orbit is in freefall and expending none of its own energy to stay in that state. To change orbits, either up OR down requires a change in velocity, and that change in velocity requires fuel. So up is just as difficult as down energy wise.
The only free ride you get in the down direction is when you get low enough so that atmospheric drag begins to slow you down.
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
Cost of a Space shuttle: $700,000,000 per launch (not counting the latest $2,000,000,000 in upgrades or the initial cost)
22 tons http://www.braeunig.us/space/specs/shuttle.htm
Even taking into account inflation, the Saturn 5 still looks better.
Purely science fiction?
The Russians built and launched one (which failed due to technical problems). The concept is certainly within our reach.
Also, solar sails would work in low earth orbit. Photons of light impart force, not just the solar wind. That's how (as another example) those laser propelled spacecraft ideas would work, as well.
Umm... now for a clue. The next scope has already been justified. It is the James Webb Telescope. It is huge and will be orbited around the Earth-Moon L2 point. The last schedule I saw had it launching in 2010 (But I hope someone can provide more recent info). The Hubble has been wonderful. Its replacement is on the way. We can live with a 2 or 3 year gap. The universe will wait. ... And NASA needs the money for other stuff. Now if we could only get Babs Mikulski (Senator from Md) to stop forcing NASA to spend its money where she wants it, maybe we can do a few other amazing/needed things with NASA funding.
-- Instant Karma's gonna get you! [320848 = 2*2*2*2*11*1823]
The problem is that Hubble is already low enough that atmospheric drag slows it down. It already expends fuel on a regular basis to update its orbit. IN fact, there isn't a need to fire the engines to bring Hubble back in. It will come down on its own eventually. The reason to save some fuel and bring it down on its own power is for timing...so that it does land in the ocean and not a highly populated area, just in case it doesn't all burn up in the atmosphere. Also, this applies to low earth orbit. Those geosynchronous satellites are far enough out there that from an energy view its easier to break from orbit "up" (escape Earth into solar orbit) than to come back to Earth
Everything you said is correct except Hubble has no engines to fire - it has no thrusters. It depends on boosts from the Shuttle to keep it from deorbiting just like the space station does.
Hubble is so high up that it would take years for atmospheric drag to cause a de-orbit. To cause a controlled de-orbit means flying up and attaching a thruster. Since they had (still have) to do this anyway, trying to repair it wasn't that much more expensive.
Tesla was a genius. Edison however was a overrated hack who liked to torture puppies.
The main advantage of space for a telescope was avoiding atmospheric distortion. Now it is possible to adjust the mirrors to compensate for atmospheric distortion (adapive optics), enabling large and clear telescopes on the ground (Earth). Here's an explanation of how a guide star is used to "eliminate twinkling". In short, orbital telescopes may be obsolete once these technologies are perfected.
to err is human, to forgive is divine, to forget is... umm...
Why not just do nothing and leave it up there?
It's falling out of orbit (slowly) and there's a 1 in 700 chance it'll hit people when it lands. They want to bring it down into an ocean under control.
It only has enough battery and gyroscope life left to be useful for another couple years without service so at that point it's just a danger and they've deemed it too risky to fix.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)
That's right. Which means that all those gorgeous images the previous poster was talking about will no longer be available other than with false color.
Why they can't put a visible light CCD on the JWT is beyond me, but whatever. Not to mention the fact that the JWT will be impossible to service at a LaGrange point.
+++ATH0
Actually, the James Webb Telescope will orbit the Sun-Earth L2 point.