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."
If Slashdot allowed image posting, this is where I'd post that picture from "UHF" where all the Asian dudes come out of the closet and yell "SUPPLIES!"
But I can't do that, so the point is probably moo.
Joey: Because if he doesn't like you, this is all a moo point.
Rachel: Huh. A moo point?
Joey: Yeah, it's like a cow's opinion. It just doesn't matter. It's moo.
Why do these articles always tell us how difficult it was to do something in space because they are going so ridiculously fast? When taken relatively, they were practically sitting still while docking.
I know there are all kinds of other factors and I know it takes a lot of math to even get to the right orbit at the right time and speed to even see the Hubble, but after that, it ought to be relatively simple considering the lack of any unwanted or unexpected force on the crafts. I'm pretty sure it's much more difficult to land a jet on an air craft carrier, but I wouldn't know for sure.
I know there are all kinds of other factors and I know it takes a lot of math to even get to the right orbit at the right time and speed to even see the Hubble, but after that, it ought to be relatively simple considering the lack of any unwanted or unexpected force on the crafts. I'm pretty sure it's much more difficult to land a jet on an air craft carrier, but I wouldn't know for sure.
Exactly right, we've been doing it for overy forty years -
I know there are all kinds of other factors and I know it takes a lot of math to even get to the right orbit at the right time and speed to even see the Hubble, but after that, it ought to be relatively simple considering the lack of any unwanted or unexpected force on the crafts. I'm pretty sure it's much more difficult to land a jet on an air craft carrier, but I wouldn't know for sure.
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.
"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.
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.
Exactly.
Here's a simple question for those who say this is easy to work out:
You have an orbiter with a mass of 80,000kg drifting towards a telescope with a mass of 11,000kg in an essentially frictionless environment, just like your physics teachers used to say and love. They are directly approaching each other at 10 millimeters per secon
Ah, no, the Shuttle actually did have to accelerate to 17000 mph from when it took off until it docked, with precise positioning. It's by no means easy, only a few nations are capable of it. I thought the X-Prize was pretty cool, but for that matter, they never even reach orbit.
I've told this story before on slashdot, but once--about 10 years ago--the shuttle flew over Austin, TX on descent to land in FL not long after sunset. We went outside to see the boiling plasma trail it left in the atmosphere, then went back inside to see it touch down 9 MINUTES LATER.
So they're going 17,200mph relative to the surface of the Earth? How fast are they going relative to some arbitrarily fixed point in the universe? Relative to another galaxy, we're hurtling towards it at some million mph, so maybe count that in as well.
I am reaching for my pop can while we travel at over 1 million miles per hour. SUCCESS! POP CAN LINKUP COMPLETE!
I think you have it backwards. He understood that there is no actual fixed reference. He just meant that choosing the earth as a reference point didn't help one determine whether the linkage was difficult or not. Short answer: cut him some slack.
That's why reading the context is important. That little word "arbitrarily" before "fixed point" means that you just chose something to USE as a fixed point. Which is PRECISELY what relativity is.
So they're going 17,200mph relative to the surface of the Earth? How fast are they going relative to some arbitrarily fixed point in the universe? Relative to another galaxy, we're hurtling towards it at some million mph, so maybe count that in as well.
So why don't you go up there and show 'em how it's done?
How fast are they going relative to some arbitrarily fixed point in the universe?
I am also manipulating a soda container at 552 km/s (1.23M mph), relative to the CMB rest frame [astro.ubc.ca]. Most highly trained soda operators are capable of this.
Since it's the relative speed that's important. The speed figures are only of use for those that tracks the shuttle and the telescope.
Sometimes it's just baffling to see people goo "ooh" when someone states that they makes an extreme speed and then the people thinks that going that fast must be very dangerous.
In a way it is, but only if something crosses your path. But that's the same when you are on the ground too.
Of course, relative speed from the Shuttle to Hubbles is tiny.
But to match their relative speed from the ground is still pretty hard. Getting the shuttle from zero MPH to 17,000+MPH within inches of the Hubble so that their own relative speed nears zero for a dock is by all means, pretty neat stuff.
Sometimes it's just baffling to see people goo "ooh" when someone states that they makes an extreme speed and then the people thinks that going that fast must be very dangerous.
Well, the historical evidence confirms they're right, and you're wrong. Yes, you really do have to sit on top of enough propellent to push that massive shuttle straight up into the air and accelerate it to 17000 mph, with pinpoint precision. And sometimes, it blows up and everybody dies.
If two objects were flying formation in the Earth's atmosphere at Mach 3, matching their relative speed would be a big deal.
Under terrestrial conditions, there are all manner of random perturbations and ways that energy can couple into systems (i.e. make them smash) that flying high speed formation is tricky. It is even more serious at supersonic speed and that is why rocket staging is non-trivial and all the problems Space-X was having with rocket tests.
They didn't spend a fortune putting the Hubble in a higher, more remote orbit for laughs. Lower orbits get more drag from the atmosphere. Anywhere close to the IIS and the Hubble's very delicate instruments and optics would be degraded by all the outgassing from the IIS, the rocket exhaust from visiting vessels. And all the bits and pieces that have fallen off the IIS over the years would be a big hazard. Would take just one bolt moving at high speed to smash a billion dollar mirror.
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:
Ed Weiler, NASA administrator
David Leckrone, Hubble senior scientist
Robert O'Connell, committee chair for one of the two new instruments
James Green, principal investigator for the other new instrument
Heidi Hammel, scientist representing users of Hubble
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.
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!
Just in the last 24 hours we got a story on Slashdot about the new 30 meter telescope being built. Given the cost to fix Hubble and the non-zero danger that is present, why are we even bothering with it any more? The new 30 meter telescope will have 100x the power of Hubble and allow us to do everything we ever wished, including make upgrades and repairs as needed - all less than for the cost of the launch to repair Hubble(The 30 meter telescope is projected to cost 700-800 million versus 1.3 billion for just one Shuttle launch).
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.
Because space telescopes can see radiation distorted or blocked entirely by the atmosphere, and repairing the Hubble is still cheaper than making a new space telescope. Sure, the TMT will have better resolving power, but that won't make it any more able to detect what isn't there.
Hubble does things that ground-based telescopes can not. Wikipedia states it well:
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.
Just in the last 24 hours we got a story on Slashdot about the new 30 meter telescope being built. Given the cost to fix Hubble and the non-zero danger that is present, why are we even bothering with it any more?
Because Hubble can do a number of important things that ground based scopes can't possibly do - like looking deep into the parts of the IR and UV bands that the atmosphere absorbs.
The new 30 meter telescope will have 100x the power of Hubble and allow us to do everything we ever wish
Except if you actually follow the links and read the comments - you find that at best the Keck merely equals the performance of Hubble, it doesn't even remotely outclass it.
Equaling Hubble but not costing 1.3 billion for a Shuttle launch to fix it is a big deal to me. It's not only that newer ground based telescopes are catching up with it. It's also about the insane cost to keep it running. That we can almost build two of those 30 meter telescopes for the cost of this one Shuttle launch makes me wonder why we bother.
It's not like we're rolling in money, either. Hubble was great when it was launched, but it's just to expensive to run any more. And God help us if we need t
"flying through space at 17,200 MPH, 300 miles above the Earth's surface. " Not impressive.
Then let's see you do it.
Give him 45 years, a multi-billion dollar budget, proven launch and flight platforms with 20+ years of successful flights, a number of catastrophic failures to learn from and a 50 odd professional test pilots and I'm sure he could do better than dock with a satellite in orbit.
NASA does more impressive stuff than this every day, and could be doing even more stuff if they were better managed and funded.
Women are more easily and more deeply terrified ... generating more
sheer horror than the male of the species.
-- Spock, "Wolf in the Fold", stardate 3615.4
The Hubble can repair the Shuttle? (Score:2, Funny)
Re:The Hubble can repair the Shuttle? (Score:5, Funny)
If Slashdot allowed image posting, this is where I'd post that picture from "UHF" where all the Asian dudes come out of the closet and yell "SUPPLIES!"
But I can't do that, so the point is probably moo.
Parent
Re:The Hubble can repair the Shuttle? (Score:5, Funny)
I can't do that, so the point is probably moo.
t
Hi, you dropped this while typing your post. I thought you might want it back.
Parent
Re:The Hubble can repair the Shuttle? (Score:5, Funny)
Joey: Because if he doesn't like you, this is all a moo point.
Rachel: Huh. A moo point?
Joey: Yeah, it's like a cow's opinion. It just doesn't matter. It's moo.
Parent
ILzy Susan? (Score:5, Funny)
Is that like an epileptic version of a lazy susan? I don't even know how you make a typo like that without having some sort of seizure.
Re: (Score:2)
LOL! I was thinking the same thing.
Personally, I prefer the Lazy Bob [mybobs.com].
Re:ILzy Susan? (Score:5, Funny)
Parent
How about Relative Speed? (Score:5, Insightful)
Why do these articles always tell us how difficult it was to do something in space because they are going so ridiculously fast? When taken relatively, they were practically sitting still while docking.
I know there are all kinds of other factors and I know it takes a lot of math to even get to the right orbit at the right time and speed to even see the Hubble, but after that, it ought to be relatively simple considering the lack of any unwanted or unexpected force on the crafts. I'm pretty sure it's much more difficult to land a jet on an air craft carrier, but I wouldn't know for sure.
Re: (Score:2)
I know there are all kinds of other factors and I know it takes a lot of math to even get to the right orbit at the right time and speed to even see the Hubble, but after that, it ought to be relatively simple considering the lack of any unwanted or unexpected force on the crafts. I'm pretty sure it's much more difficult to land a jet on an air craft carrier, but I wouldn't know for sure.
Exactly right, we've been doing it for overy forty years -
Apollo 13 CSM Seperation (sic) and Docking:
http://www. [youtube.com]
Re:How about Relative Speed? (Score:4, Funny)
we can even land on asteroids: http://www.youtube.com/watch?v=UbFVPDhlIBQ [youtube.com]
(use footage from nasa's archives, not movies!)
Parent
Re: (Score:3, Funny)
Re:How about Relative Speed? (Score:5, Funny)
Parent
Re: (Score:3, Funny)
I can't understand it either, as I sit here, very carefully typing, going 17,880 MPH around the Sun.
I find it very amusing that such an orbital speed would put you somewhere in the neighborhood of Uranus.
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...
Parent
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.
Parent
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.
Parent
Re: (Score:3, Interesting)
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.
Exactly.
Here's a simple question for those who say this is easy to work out:
You have an orbiter with a mass of 80,000kg drifting towards a telescope with a mass of 11,000kg in an essentially frictionless environment, just like your physics teachers used to say and love. They are directly approaching each other at 10 millimeters per secon
17,000 mph (Score:3, Insightful)
Do people just look for big numbers to sound impressive??
The important number is the relative speed between Hubble and the shuttle. From my very precise calculation it was zero.
Re:17,000 mph (Score:5, Insightful)
Parent
Re:17,000 mph (Score:5, Interesting)
I've told this story before on slashdot, but once--about 10 years ago--the shuttle flew over Austin, TX on descent to land in FL not long after sunset. We went outside to see the boiling plasma trail it left in the atmosphere, then went back inside to see it touch down 9 MINUTES LATER.
Fast, indeed.
Parent
Relative speeds (Score:5, Funny)
So they're going 17,200mph relative to the surface of the Earth? How fast are they going relative to some arbitrarily fixed point in the universe? Relative to another galaxy, we're hurtling towards it at some million mph, so maybe count that in as well.
I am reaching for my pop can while we travel at over 1 million miles per hour. SUCCESS! POP CAN LINKUP COMPLETE!
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".
Parent
Re:Relative speeds (Score:4, Insightful)
I think you have it backwards. He understood that there is no actual fixed reference. He just meant that choosing the earth as a reference point didn't help one determine whether the linkage was difficult or not. Short answer: cut him some slack.
Delta-V, FTW!
-l
Parent
Re: (Score:3, Insightful)
No.. but one can "arbitrarily" select a fixed point as a reference.. as the parent poster stated.
"I arbitrarily choose the earth as the fixed point in the universe for all my velocity calculations."
See?
Re: (Score:3, Insightful)
Re: (Score:3, Informative)
Re: (Score:2)
So they're going 17,200mph relative to the surface of the Earth? How fast are they going relative to some arbitrarily fixed point in the universe? Relative to another galaxy, we're hurtling towards it at some million mph, so maybe count that in as well.
So why don't you go up there and show 'em how it's done?
Re:Relative speeds (Score:4, Funny)
no you mean 64.
it's just that your arbitrary reference for 0 is what others call +1.
Cheers,
-nB
Parent
Re:Relative speeds (Score:5, Funny)
How fast are they going relative to some arbitrarily fixed point in the universe?
I am also manipulating a soda container at 552 km/s (1.23M mph), relative to the CMB rest frame [astro.ubc.ca]. Most highly trained soda operators are capable of this.
Parent
Speed figures are meaningless (Score:2, Redundant)
Since it's the relative speed that's important. The speed figures are only of use for those that tracks the shuttle and the telescope.
Sometimes it's just baffling to see people goo "ooh" when someone states that they makes an extreme speed and then the people thinks that going that fast must be very dangerous.
In a way it is, but only if something crosses your path. But that's the same when you are on the ground too.
Re:Speed figures are meaningless (Score:4, Insightful)
You make it sound as if it was simple.
Of course, relative speed from the Shuttle to Hubbles is tiny.
But to match their relative speed from the ground is still pretty hard. Getting the shuttle from zero MPH to 17,000+MPH within inches of the Hubble so that their own relative speed nears zero for a dock is by all means, pretty neat stuff.
And for that, I go Oooh.
Parent
Re: (Score:3, Insightful)
Well, the historical evidence confirms they're right, and you're wrong. Yes, you really do have to sit on top of enough propellent to push that massive shuttle straight up into the air and accelerate it to 17000 mph, with pinpoint precision. And sometimes, it blows up and everybody dies.
Relative speed only meaningless in vacuum (Score:3, Insightful)
Under terrestrial conditions, there are all manner of random perturbations and ways that energy can couple into systems (i.e. make them smash) that flying high speed formation is tricky. It is even more serious at supersonic speed and that is why rocket staging is non-trivial and all the problems Space-X was having with rocket tests.
But in the vacuum of Earth orbital space, there
Not very difficult... (Score:5, Funny)
I used to bullseye wamprats in my T16 back home and they're not much bigger than the hubble
Attach it to IIS (Score:2)
Would it be possible to drag the telescope and attach it to the space station.
Seems like it would be a lot easier to service. Not to mention that cool Canada arm could work on it for years to come for a fraction of the cost.
Hand over ownership to the international community and split the costs might also help.
Re: (Score:3, Informative)
It was the hardest kiss in my life (Score:3, Funny)
Re: (Score:3, Funny)
She and I were standing on the earth, which was moving around the sun at 67,000 miles per hour. We struggled to make our lips meet...
You're a lucky man! Most of my liaisons appear to be with people who are not on the same planet as me at all.
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!
Obsolete Already? (Score:3, Interesting)
Just in the last 24 hours we got a story on Slashdot about the new 30 meter telescope being built. Given the cost to fix Hubble and the non-zero danger that is present, why are we even bothering with it any more? The new 30 meter telescope will have 100x the power of Hubble and allow us to do everything we ever wished, including make upgrades and repairs as needed - all less than for the cost of the launch to repair Hubble(The 30 meter telescope is projected to cost 700-800 million versus 1.3 billion for just one Shuttle launch).
http://science.slashdot.org/article.pl?sid=08/11/13/2010241&from=rss [slashdot.org]
Hubble's already outclassed by Keck as well - so ground-based telescopes already make it almost entirely redundant.
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.
Parent
Re: (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.
Parent
Re: (Score:3, Insightful)
Because Hubble can do a number of important things that ground based scopes can't possibly do - like looking deep into the parts of the IR and UV bands that the atmosphere absorbs.
Re: (Score:3, Interesting)
Except if you actually follow the links and read the comments - you find that at best the Keck merely equals the performance of Hubble, it doesn't even remotely outclass it.
Equaling Hubble but not costing 1.3 billion for a Shuttle launch to fix it is a big deal to me. It's not only that newer ground based telescopes are catching up with it. It's also about the insane cost to keep it running. That we can almost build two of those 30 meter telescopes for the cost of this one Shuttle launch makes me wonder why we bother.
It's not like we're rolling in money, either. Hubble was great when it was launched, but it's just to expensive to run any more. And God help us if we need t
17,200, shmeventeen thousand two hundred... (Score:4, Funny)
Re:impressive/not impressive (Score:5, Funny)
"flying through space at 17,200 MPH, 300 miles above the Earth's surface. " Not impressive.
Then let's see you do it.
Parent
Re:impressive/not impressive (Score:4, Funny)
Do you have a U.S. government that I can borrow for awhile?
Parent
Re:impressive/not impressive (Score:5, Insightful)
Parent
Re: (Score:3, Insightful)
"flying through space at 17,200 MPH, 300 miles above the Earth's surface. " Not impressive.
Then let's see you do it.
Give him 45 years, a multi-billion dollar budget, proven launch and flight platforms with 20+ years of successful flights, a number of catastrophic failures to learn from and a 50 odd professional test pilots and I'm sure he could do better than dock with a satellite in orbit.
NASA does more impressive stuff than this every day, and could be doing even more stuff if they were better managed and funded.