Atlantis Links Up To Hubble For Repairs 132
An anonymous reader writes "Space Shuttle Atlantis has finally caught up with the Hubble Space Telescope after following it for several hours. The 'link up' between the Space Shuttle and Hubble was a very delicate one as the two were flying through space at 17,200 MPH, 300 miles above the Earth's surface. The robotic arm of the shuttle grappled the telescope at 1:14 PM EDT today. The telescope will be latched to a high-tech Lazy Susan device known as the Flight Support System for the duration of the servicing work."
Re:Relative speeds (Score:4, Informative)
"relative to some arbitrarily fixed point in the universe"
I think you just made Einstein cry.
And in a post about the importance of relative measurements, no less.
There is no such thing as a "fixed point in the universe".
Re:Lulzy Susan? (Score:1, Informative)
listen to Dr. Hammel's short speech about Hubble (Score:5, Informative)
Last fall during the run-up to the original launch date, NASA conducted their usual round of press briefings on this mission, 30 days prior to launch. The briefings included the usual information about the mission, the crew, the scheduled spacewalk work, etc.
In addition to those briefings typical for any shuttle flight, they conducted a "science briefing" to explain what the work of this servicing mission was going to do for the scientific capabilities of Hubble. In the briefing was an all-star cast of astronomical scientists:
Each of them made a short speech and then the rest of the briefing was turned over to questions from the press. I would encourage anyone with even a fleeting interest in science or astronomy to take the time to download and watch the entire briefing, as it is truly fantastic stuff they're talking about, and these guys do a great job of explaining it to regular people. Certainly science could use a bit of a pep talk after weathering the last 8 years of the Bush administration's hostility to science and objective truths.
In particular, the last person on the dais, Dr. Hammel, give an impassioned 10-minutes speech on the impact of Hubble on science and indeed on culture. It's an astonishing and beautiful statement on where we are in astronomical science and where we may be headed if this shuttle mission goes as planned. I'm surprised the press room didn't erupt in applause when she finished.
Dr. Hammel's speech starts at the 38:50 mark in the first half of the briefing that I've linked below. If you don't have time to watch the entire 90-minute briefing, at least watch her 10 minutes.
download page for first half of briefing [eu.org]
download page for second half of briefing [eu.org]
The above is adapted from an entry that I made to my personal blog back in September (not linked here). Sadly, I see that the above download links no longer work. I have not been able to find the briefing on Youtube, and the repeat briefings from a couple weeks ago did not include Dr. Hammel. FORTUNATELY, I did find most of Dr. Hammel's speech incorporated into a nice 5 minute video right here [youtube.com]. Please check it out!
Re:How about Relative Speed? (Score:4, Informative)
If I remember my orbital mechanics, it's actually quite tricky. First, let's eliminate the orbital plane, and assume we're just orbiting in the same plane as some other object flying around.
Firstly, the only way to match altitudes is with speeds - the faster you go, the higher up you go. Ah, but then you must make your speed adjustment at the right time - if you don't meet up at altitude, you and the object will be orbiting at the same speed and will never catch each other. You could speed up some, but then you'll go into a higher orbit, or slow down some and go into a lower orbit. Thrusters help for minor speed and altitude/attitude corrections.
Secondly, you must do this within a resource budget - gas (for thrusters), oxygen (for crew), power, which means you must do it within a few orbits. You can't endlessly orbit.
Now remove the planar restriction...
Try it yourself (Score:5, Informative)
There's a free (beer) spaceflight simulator available at http://orbit.medphys.ucl.ac.uk/orbit.html [ucl.ac.uk] that lets you try these sorts of approaches.
Re:Obsolete Already? (Score:2, Informative)
Well, from talking to an Astronomer friend of mine:
1. Hubble is cheaper to repair and get good science out of than to purchase time on other ground based telescopes (shuttle costs not included)
2. Hubble is up and running, the new 30 meter scope won't be done for a while
3. Clouds/rain/etc suck
4. Hubble has a greater field of vision than ground based telescopes (not limited to what you can see from your spot on the ground).
Re:Relative speeds (Score:3, Informative)
Re:Obsolete Already? (Score:5, Informative)
Just in the last 24 hours we got a story on Slashdot about the new 30 meter telescope being built.
Hubble works, and has worked, for years now. Why abandon something we have right now for something that we might have in 2018 assuming it's finished on time? While we're waiting, we should also demolish all ground based telescopes that will be inferior and just put science on hold until then.
Hubble's already outclassed by Keck as well - so ground-based telescopes already make it almost entirely redundant.
Hubble can see ultraviolet, Keck can't. Even if it could, Hubble doesn't have to worry about the atmospheric turbulence.
Not an issue at these time scales. (Score:5, Informative)
"Firstly, the only way to match altitudes is with speeds - the faster you go, the higher up you go. ..."
That's only an issue if your drift time between velocity adjustments is an appreciable fraction of a quarter-orbit. For significantly shorter times the orbital mechanics of the goofy accelerated reference frame is no big deal.
This was delicate because the instrument they're linking up with is massive and fragile. No hard bumps during grabbing or thruster exhaust spraying the device is acceptable.
Re:Obsolete Already? (Score:3, Informative)
Re:Obsolete Already? (Score:4, Informative)
Although the HST has clearly had a significant impact on astronomical research, the financial cost of this impact has been large. A study on the relative impacts on astronomy of different sizes of telescopes found that while papers based on HST data generate 15 times as many citations as a 4 m ground-based telescope such as the William Herschel Telescope, the HST costs about 100 times as much to build and maintain.[83]
Making the decision between investing in ground-based versus space-based telescopes in the future is complex. Even before Hubble was launched, specialized ground-based techniques such as aperture masking interferometry had obtained higher-resolution optical and infrared images than Hubble would achieve, though restricted to targets about 108 times brighter than the faintest targets observed by Hubble.[84][85] Since then, advances in adaptive optics have extended the high-resolution imaging capabilities of ground-based telescopes to the infrared imaging of faint objects. The usefulness of adaptive optics versus HST observations depends strongly on the particular details of the research questions being asked. In the visible bands, adaptive optics can only correct a relatively small field of view, whereas HST can conduct high-resolution optical imaging over a wide field. Only a small fraction of astronomical objects are accessible to high-resolution ground-based imaging; in contrast Hubble can perform high-resolution observations of any part of the night sky, and on objects that are extremely faint.
In short, Hubble does high-resolution photos and photos of faint objects well because it does not have to deal with the atmosphere.
Re:Attach it to IIS (Score:3, Informative)