Hubble will not be repaired

[kheegster]

First that new telescope looks like it might be a pretty good one.
Second I think I much perfer ESA way of doing business
And third if one of the satellite companies could build a telescope and then charge a small user fee I wonder if that would work.

The amount of human capital required to built a scientific space mission is beyond virtually all commercial companies, and for the major ones, you really need international cooperation. You need armies of scientists just to get the mission profile, objectives, etc worked out before any of the physical construction even takes place, and during the operational phase you need scientists continuously dealing with the data as well.

[Julhelm]

Maybe the general public doesn't give a shit anymore seeing as how it's 36 years since Armstrong took a walk on the moon? Government-funded space programs have had their prime, and with the demise of the Soviet Union, outlived their real usefulness, and it will be the coming generation of private sector projects that will make space "exiting" again. And since there apparently is a more powerful replacement in the works, what's the problem?

[Alyrium Denryle]

Fuck out law-makers, fuck them right in the ear

Though, I will say that this would be a perfect job for the private sector, as renting out telescope time to universities would be very very profitable.

[kheegster]

considering the ting was only designed to last 4 or 5 years, and they managed to keep it running for more than 10, I don't see what the big deal is.

Original mission lifetime was 15 years, with shuttle servicing missions every 3-4 years. We're just at the end of that planned lifetime, but if you already have a tried and proven telescope up there and all you need to keep it ticking along indefinitely is to send a shuttle up, why not?

[kheegster]

Fuck out law-makers, fuck them right in the ear

Though, I will say that this would be a perfect job for the private sector, as renting out telescope time to universities would be very very profitable.

Private sector? EVERY single telescope in the world is run by universities or groups of universities, or otherwise by governmental organisations. There's absolutely NO economic sense whatsoever in privatisation of astronomy, nor for most of pure science for that matter.

[kheegster]

The Webb Telescope is IR, yes, but that's because ground-based observation can do a much better job of that with tricks like adaptive optics. Hubble's puny mirror is no match for the large telescope or telescope arrays on the ground now.

OTOH, the atmosphere absorbs a lot of IR, so it makes sense to have Webb do that.

Even with the 10m monster on Mt Keck, you'd be hard pressed to get resolutions of as small as 0.3 arcsec, and this is with the exceptional seeing conditions there which are almost unique there. The HST routinely takes images with 10 times better resolution:


Instrument handbook for HST's Advanced Camera for Surveys

[kheegster]

The Webb Telescope is IR, yes, but that's because ground-based observation can do a much better job of that with tricks like adaptive optics.

OTOH, the atmosphere absorbs a lot of IR, so it makes sense to have Webb do that.

Adaptive optics work ONLY with infra-red....it wouldn't work for wavelengths less than 2 microns or so, which is still in the mid-IR. From the NIR downwards, the Hubble is king of the sky.

The JWST has a much larger collecting area than the HST, but it'll work mostly in the IR. The diffraction limit of any telescope is directly proportional to the wavelength of the light, so even though the JWST is several times larger than HST, the best resolution is about the same as HST.

Anyway, there are many areas of study in which the HST can do, but is not within the capabilities of JWST. For example, in the study of distant galaxies, the JWST is almost useless because galaxies look uniform in the IR, so you can't see spiral structures etc.

Same logic applies to missions in the other parts of the EM spectrum... XMM-Newton, Chandra, FUSE, Swift etc are all wonderful things, but they will not do what the Hubble does.

[Lord Zentei]

Bah. Scrap a perfectly good telescope when building a new one would be vastly more expensive. Lawmakers are morons. Why don't they just quit micromanaging agencies in this asinine way? Since when is your average representative from Hicksville an expert on resource allocation in space agencies for fuck's sake?

[dr. what]

In December, after the National Academy of Sciences issued a report calling on NASA to reinstate a space shuttle mission to refurbish Hubble, Congress followed up by directing NASA to spend $291 million this year preparing for some type of Hubble servicing mission. NASA’s initial operating plan for 2005, sent to Congress late last year for its review, only set aside $175 million of that amount for Hubble, with the rest of the money allocated to other agency priorities

Am I reading that right? They're going to dump it in the ocean because they can't cough up 120 million dollars?

[kheegster]

In December, after the National Academy of Sciences issued a report calling on NASA to reinstate a space shuttle mission to refurbish Hubble, Congress followed up by directing NASA to spend $291 million this year preparing for some type of Hubble servicing mission. NASA’s initial operating plan for 2005, sent to Congress late last year for its review, only set aside $175 million of that amount for Hubble, with the rest of the money allocated to other agency priorities

Am I reading that right? They're going to dump it in the ocean because they can't cough up 120 million dollars?

Even more priceless.....NASA is commited to ensuring that the Hubble does not harm anyone upon reentry. The odds of anyone getting killed by debris from the Hubble is something like 10,000 to 1, yet NASA has to use a robotic mission to install a de-orbiting module to the HST to ensure it falls into the ocean. This effort will cost at least half a billion bucks.

So they're gonna spend half a billion to nullify that 10,000 to 1 odds, but they can't fork out just a bit more to have it performing useful science for another decade.

[Lord Zentei]

Even more priceless.....NASA is commited to ensuring that the Hubble does not harm anyone upon reentry. The odds of anyone getting killed by debris from the Hubble is something like 10,000 to 1, yet NASA has to use a robotic mission to install a de-orbiting module to the HST to ensure it falls into the ocean. This effort will cost at least half a billion bucks.

So they're gonna spend half a billion to nullify that 10,000 to 1 odds, but they can't fork out just a bit more to have it performing useful science for another decade.

That's micromanagement by morons for you.

[Crown]

The Webb Telescope is IR, yes, but that's because ground-based observation can do a much better job of that with tricks like adaptive optics.

OTOH, the atmosphere absorbs a lot of IR, so it makes sense to have Webb do that.

Adaptive optics work ONLY with infra-red....it wouldn't work for wavelengths less than 2 microns or so, which is still in the mid-IR. From the NIR downwards, the Hubble is king of the sky.

The JWST has a much larger collecting area than the HST, but it'll work mostly in the IR. The diffraction limit of any telescope is directly proportional to the wavelength of the light, so even though the JWST is several times larger than HST, the best resolution is about the same as HST.

I'm sorry, but you're wrong. The HST beats the JWST in the UV range, not the visible;

JWST's wavelength range will be from about 0.6 to 28 microns (visible to the mid-infrared light), as compared to Hubble's 0.1-2.5 microns (ultraviolet to the near infrared). One micron, or micrometre, is one millionth of a metre.

source

Anyway, there are many areas of study in which the HST can do, but is not within the capabilities of JWST. For example, in the study of distant galaxies, the JWST is almost useless because galaxies look uniform in the IR, so you can't see spiral structures etc.

I'm sorry but you are wrong again;

So why is it so important to see in infrared?

Many of the things scientists want to observe in space are far too cold to radiate at optical or shorter wavelengths, but radiate strongly in infrared, for example, the cold atoms and molecules that drift in interstellar space. We need to study these raw materials to understand how stars form and evolve.

“By observing in the infrared we can study how things get formed, the very early steps, because formation processes very often happen in cool and dusty places,” explains Göran Pilbratt, ESA’s Herschel Project Scientist.

In our own Solar System, cold objects such as comets and asteroids reveal most of their characteristics to us in infrared light.


Dark cloud seen by ISO, one of ESA's ghosts

Dark cloud seen by ISO, one of ESA's ghosts

Other things of great interest to astronomy are hidden within or behind vast clouds of gas and dust. These clouds hide stars and planets in early stages of formation and the powerful cores of active galaxies.

Our view is blocked because the dust grains are very effective at scattering or absorbing visible light. Longer infrared wavelengths can get through the dust.


The future is extremely bright for infrared astronomy and, in the next decade, you will hear a lot about ESA discoveries in infrared astronomy!

source

Same logic applies to missions in the other parts of the EM spectrum... XMM-Newton, Chandra, FUSE, Swift etc are all wonderful things, but they will not do what the Hubble does.

You are right, together they will do more. That is the point. They are planning replacements for the Hubble, each slightly overlapping each other to cover all their bases. I will say it again, the Hubble has been a great workhorse, and I am sad that it isn't going to stay up there forever, and I'm not being sarcastic, but there are projects on the horizon (on the launch pad, a few years away, on the drawing boards) which will do all that Hubble did and more.

[ClaysGhost]

Adaptive optics is very good in the infra-red. It gets less good as the frequency (wavelength) increases (decreases). In all cases it requires a bright star near to your target for use as a phase reference (rare) or alternatively a laser guide star facility (also rare). The degree of correction you get depends on a lot of factors, including the local atmospheric conditions, the nearness of the guide star, the phase of the moon and the number of chickens sacrificed to a higher purpose by desperate astronomers. The degree of correction actually obtained may include "none at all" for many targets and conditions, and often does not reach HST's level; forget about improving on it. In contrast the great thing about HST is that the angular resolution is completely repeatable - ground-based angular resolution is not. When Hubble goes there will certainly be a large gap left in high-resolution optical coverage. That is sad, and rather crippling in some fields of astronomy that HST drove.

However, just as Hubble revolutionised optical astronomy, JWST will do the same for infra-red astronomy. New fields and areas of research will be driven or even created by this telescope. Also, forget any worries about a lack of pretty pictures. Many of the pretty pictures from the HST use filters in the near infra-red or ultraviolet. All that's required to produce pretty coloured images are an appropriate set of filters (or actually even an inappropriate set) and (usually fatal for gamma-ray observatories) high surface-brightness sources that cooperate by displaying lots of detail at your telescope's resolution range. JWST will have no problems here. You can work with even more exotic wavelengths than the infra-red, for that image combines far infra-red and radio. Looks reasonably pretty to me.

Now, whether JWST survives as a project through further years of Pax Americana enforcement and this "Mars is cool" fad is anyone's guess, although given that they have international partners it's more likely to be built than many other NASA projects.

[kheegster]

I'm sorry, but you're wrong. The HST beats the JWST in the UV range, not the visible;

JWST's wavelength range will be from about 0.6 to 28 microns (visible to the mid-infrared light), as compared to Hubble's 0.1-2.5 microns (ultraviolet to the near infrared). One micron, or micrometre, is one millionth of a metre.

source

The visible is usually defined to be from (~0.3-0.7 microns). So the JWST extends just a bit into the red part of the visible spectrum.

Anyway, there are many areas of study in which the HST can do, but is not within the capabilities of JWST. For example, in the study of distant galaxies, the JWST is almost useless because galaxies look uniform in the IR, so you can't see spiral structures etc.

I'm sorry but you are wrong again;

Nice try posting a picture of the nearest major galaxy to us...even my grannie's eyes can pick out spiral structure in that. Spiral arms tend to be composed of young stars and star-forming material, so optical/UV shows them better compared with IR. But point remains that JWST will not be able to take over a lot of HST's capabilities.

http://www.galex.caltech.edu/SCIENCE/UV.html

You are right, together they will do more. That is the point. They are planning replacements for the Hubble, each slightly overlapping each other to cover all their bases. I will say it again, the Hubble has been a great workhorse, and I am sad that it isn't going to stay up there forever, and I'm not being sarcastic, but there are projects on the horizon (on the launch pad, a few years away, on the drawing boards) which will do all that Hubble did and more.

'A few years away'.....From the initial announcement of opportunity to approval can take 3-4 year at least, and it's not going to leave the launch-pad till at least a decade has passed, and this is even for relatively smaller missions like FUSE/ISO. The idea for JWST was floating around since before 2000, but it'll only be launched in 2011, if everything goes perfectly to plan (which is unlikely). Even if we start planning a new replacement for Hubble right now, it's not going to actually start operations until around 2020 considering the size and complexity that will be involved. By THAT time, the JWST will be nearing the end of its service lifetime. Neat huh?