Hubble mistake - Action needed

GCNRevenger · 2004-08-11 14:05:10

It just proves we're adaptable, sure there will no doubt be problems along the way, but lets just learn from the experience and not doubt it at every turn.

Space robotics is a fine idea and a useful skill for us to learn probobly... but not for Hubble. The trouble is, a robot mission is not adaptable, and if there are serious problems, the mission is a failure. Since the HST will likly die within a year after the mission is deployed, there is only one shot at this, no practice on the ground can prepare for everything. Doors being bent, screws floating away, etcetera... Its just an awful risk since this is a new thing, and it has to work perfectly on a challenging assignment the first time.

MarsDog · 2004-08-11 17:42:20

No legs ? Then http://www.space.gc.ca/asc/eng/csa_sect … asp]Dextre could use a few more arms.
-
Although more complex than a radio controlled toy, Dextre will not be a real robot,
just a http://www.theglobeandmail.com/servlet/ … ce]Special Purpose Dexterous Manipulator.

SpaceNut · 2004-08-11 19:17:42

Basically it is a mini shuttle arm remotely controlled from the ground. That's also why I did a little search on the Robonaut that Nasa has been working on for some time. Maybe multiple types of Robot is the answer to the repair solution. I am sure that there are other companies out there that would work. In fact send anything that would wish to be tried first to the ISS and see how it goes. Do this not by contract but by those companies wishing to show what they are made of.

John Creighton · 2004-08-11 19:28:22

"Do this not by contract but by those companies wishing to show what they are made of. "

There could be a prize for some ISS robotics contest.

GraemeSkinner · 2004-08-11 23:41:54

... Its just an awful risk since this is a new thing, and it has to work perfectly on a challenging assignment the first time.

Agreed, they are going to have to send along a fall back option in case it all goes pear shaped. And as much as I like Hubble, if the mods failed and time ran out a controlled entry point into our atmosphere would be much better than leaving it to chance. So what about sending a booster along with the robotic mission that can be ground controlled depending on the outcome of the repair mission.

Graeme

SpaceNut · 2004-08-12 05:30:39

If you read the link from the top of the page you will see just that.

snipet of planned repair using dexter:

NASA would launch a 12,000- to 15,000-pound spacecraft consisting of a propulsion module and an ejection module. The ejection module would contain bays for two new Hubble instruments as well as the two-armed android and a smaller version of a shuttle robot arm.

The shuttle-like arm would maneuver the two-armed robot -- a copy of which is being developed by the Canadian Space Agency for the International Space Station -- to work sites on the four-story observatory.

Also known as the Special Purpose Dexterous Manipulator, or SPDM, the robot then would remove old Hubble instruments and stow them in ejection module bays.

The two new instruments -- the Wide-Field Camera-3 and the Cosmic Origins Spectrograph -- then would be installed.

bolbuyk · 2004-08-12 07:08:12

Let's hope this will work.

GCNRevenger · 2004-08-12 08:11:57

Agreed, they are going to have to send along a fall back option in case it all goes pear shaped. And as much as I like Hubble, if the mods failed and time ran out a controlled entry point into our atmosphere would be much better than leaving it to chance. So what about sending a booster along with the robotic mission that can be ground controlled depending on the outcome of the repair mission.

Any mission to Hubble will come standard with a deorbit booster, don't worry about that... my gripe is, that since the cost is going to be quite high ($1.6Bn pricetag already, and NASA hasn't started yet) and the risk so high, that you might as well just build a new telescope with new technology... Saving Hubble, from a science-per-dollar standpoint, is a terrible idea and is just a NASA PR stunt. Where exactly is NASA supposed to get the money to fix the broken down obsolete old scope' anyway?

Oh, and I don't think that uncontrolled reentry is that big of a risk, NASA has let large objects reenter before (Compton GRT) with no problem. The chance of getting hit by falling pieces is a bit less than being struck by lightning I imagine.

SpaceNut · 2004-08-12 08:47:26

So without a manned space rocket or use of the shuttle and no other purchaseable rocket from other nations that we could use if we could pay for it. We are left to only two options of let it crash or to put up the cash.

SpaceNut · 2004-08-13 06:59:23

Addition resources on Dexter

Hubble: Robot to the rescue?
NASA moves forward with a plan to service the Hubble Space Telescope without the space shuttle.

http://www.astronomy.com/asy/default.aspx?c=a&id=2377

SpaceNut · 2004-08-13 07:27:16

No Green Light for Hubble Rescue
http://www.wired.com/news/space/0,2697, … _tophead_6

Not really a change but only no cash funds have been put forth yet and a critical design review is 9 to 12 months away.

GCNRevenger · 2004-08-13 08:08:47

Didn't think so... either A: they're counting on Bush to pressure congress to cough up the cash or B: stalling, trying to come up with a reason to ditch Hubble that the public will swallow

SpaceNut · 2004-08-13 12:43:16

C: to finally relent an send a shuttle for they feel the external tank foam issue is gone.

But in any of those repair senarios, cash flow is still the problem.
Having faith that Nasa can still do manned space flight in any fashion. The jury is still out on that IMO.

GCNRevenger · 2004-08-13 23:48:08

Even a Shuttle repair mission is going to cost nine figures... Where are they going to get that kind of money, other than to slash PlanBush down to nil or axe Mars probes?

All this for an obsolete telescope...

deagleninja · 2004-08-14 05:34:59

All this for an obsolete telescope...

Obsolete? Hardly....

Granted, the technology of the HST is 20+ years old but it is still the world's greatest telescope. The great thing about telescopes is that they never need be obsolete when you can network them to produce sharper images of very distant objects.

I realize that any servicing mission is going to cost about as much as sending a new one. So the obvious solution seems to me that NASA should build a copy of the HST, lanch it aboard the shuttle and service the old one during the same mission.

GCNRevenger · 2004-08-14 10:11:58

Actually yes, it is quite obsolete. Ground-based interferrometric scopes' with adaptive optics can be essentially as good or better than HST over large portions of the optical spectrum and be built for a tenth of the money. The modifications needed to turn HST into an interferrometric telescope would be too radical to be affordable.

In fact it would probobly be cheaper to build two new telescopes and put them on Delta-II 7000's or Atlas-V's then it would be to build one scope, plan the HST repair, and launch the $1Bn a pop Shuttle mission plus risk the crew with another TPS failure.

The HST's main mirror is only 2.4m wide. It would be easy to make a 2.0m wide folding telescope mirror I imagine, given the size of the big one NASA wants to put on JWST. Fold up telescope primary mirror, telescoping boom/truss for the secondary in the center like the Shuttle ground mapping radar boom, perhaps with a UV-hardening inflatable shroud to block the Sun and any space debries.

Low Earth Orbit is also a terrible place to put interferrometric space telescopes because of the light pollution from Earth and that some of the telescopes would be obscured every few hours as the Earth is in the way. Higher maneuvering requirements too... No, the best place is in Earth/Moon L1 or a Earth/Sun Lagrange like the SIRTF is. And you can't get there with Shuttle or push an anticent heavy glass telescope out there for any reasonable sum.

And even if we do fix HST, how long will it last? A brand new telescope would almost certainly last longer, so you get more science longer for your money...

...Do the science of Astrophysics a favor, and let Hubble fall.

bolbuyk · 2004-08-14 11:16:37

A new telescope in LEO for $1B? I can't imagine. Was Hubble that cost?

GCNRevenger · 2004-08-14 12:36:24

It doesn't matter how much Hubble cost, because a new telescope won't be built anything like it at all. Thin film metal/polymer folding main mirror, modern electronics, $100-150M launch vehicle tops. Yeah, I think we can build a new telescope of comperable capability for about $1.5Bn, give or take a hundred million. And it will be in a much better orbit at Earth/Sun Lagrange.

To fix Hubble, you have to build a $1.5-2.0Bn robot and put that on a $150M launch vehicle. And it might not work. And it will only keep HST alive for a little longer.

Or, you have to plan and send up a Shuttle mission, which is going to cost hundreds of millions or a billion to plan on top of the $1.1Bn or so that a Shuttle launch goes for. Which risks Astronauts since Shuttle doesn't have anywhere near the OMS fuel to change orbital inclination from HST to ISS orbit in the event of irreperable TPS failure.

deagleninja · 2004-08-15 05:04:46

Hubble was originally planned to cost slightly more than 1B, but due to the Challenger accident and the need to store it in a clean room for year added to the opperating costs has brought the total to $3B (and that doesn't include 4 shuttle servicing missions which cost about $1.1B a pop just to fly).

GCN's mentioned disadvantages are correct, but somewhat misleading. For the HST's 'deep space feild' the telescope remained fixed on a point for months. During this time, the Earth itself was in the way literally hundreds of times, yet Hubble was able to do the job due to the same level of computing precision that allows telescopes to be networked.

In short, LEO placement for a telescope is a trade off. Along with the drawbacks, you also have the benefit of being able to service it. Unfortunatly, our manned space program isn't any closer to transporting humans to Lagrange points and back. If we had that kind of mobility I would argue that the best place for ANY telescope is the farside of our moon.

If you take all the expences of the HST you get a 'real' cost of something like $7B, but ask yourself, what else has NASA done in the past 20 years that rivals Hubble? The answer is nothing. $7B is less than half of 1 year of NASA's budget and I for one think that answering questions like: how old is the universe, how big, and what is it's fate, are well worth it.

However, the biggest problem with HST isn't related to its aging equipment, but the people that manage it. How can NASA expect the government and the public to support increased funding for bold plans to return humans to the Moon and then venture to Mars if we don't have the meddle to venture to LEO? NASA also has a history of allowing popular programs to end prematurly, thus further alienating the public from NASA's vision. To deorbit Hubble, rather than boost its orbit is yet another example of NASA's short-sighted, tunnel vision thinking.

comstar03 · 2004-08-15 07:03:12

Because NASA made the decision to lose Hubble, then Salvage Rights should be placed on hubble and then private enterprise, fund the cost of boosting the telescope into higher orbit.

Build a Business Case to keep the hubble including developing, profitable uses for the hubble pictures for calendars and posters and other activities. Also fund through other scientific uses as a private long range telescope.

TAKE IT OUT OF NASA AND GOVERNMENT HANDS, contact SETI to add to their facilities in orbit and on earth.

deagleninja · 2004-08-15 07:41:35

comstar, good points.

I would personally like to see a follow-up to the Xprize for a similar purse to reach Hubble then a $20M purse to service it?

GCNRevenger · 2004-08-15 10:37:33

For the HST's 'deep space feild' the telescope remained fixed on a point for months. During this time, the Earth itself was in the way literally hundreds of times, yet Hubble was able to do the job due to the same level of computing precision that allows telescopes to be networked.
In short, LEO placement for a telescope is a trade off. Along with the drawbacks, you also have the benefit of being able to service it. Unfortunatly, our manned space program isn't any closer to transporting humans to Lagrange points and back.
How can NASA expect the government and the public to support increased funding for bold plans to return humans to the Moon and then venture to Mars if we don't have the meddle to venture to LEO?

Ahhh but you do need continuous simultainious viewing for interferometry to work. If the images aren't collected essentialy simultainiously, then the interferance filtering doesn't work very well. So, an interferometer space telescope network with signifigant target loiter time needs to be in a much higher orbit than LEO... its not a trade off, its a system requirement.

Furthermore, the fact of the matter is, it is cheaper to build a new one than it is to fix an old one, as far as the science-per-dollar goes. It really is. The SIRTF telescope, about half the size of "Hubble-II" would be and much more complex because of its ultracold optics, cost around half a billion.

If NASA had a competant CEV with a small payload compartment, I am sure NASA would be happy to go up and fix HST. The problem is Shuttle. The problem was Shuttle, the problem is Shuttle, and will continue to be Shuttle. NASA is not too timid to take on crazy missions, like putting people on the Moon in under a decade, but not with Shuttle. It is a debacle, a joke, a ruinous farce of a spaceship... it IS a high risk to launch it, every single time, and its sheer monetary cost quite simply is greater than the bennefit of fixing HST.

NASA is perfectly justified in cutting HST loose, because its going to cost more to fix than to replace AND carries a much higher risk (robot failure, Shuttle "incident"). Its a shame that the public isn't told this plainly, because NASA thinks they wouldn't understand or somthing. It should also be noted, that unless the money comes from a special grant from Congress, its going to have to come out of VSE or Mars probe budgets, as long as Shuttle/ISS soak up so much cash.

deagleninja · 2004-08-15 14:17:38

Yes, all good points GCN but space telescopes like the HST spend most of their time collecting light from distant galaxies so the occasional interference from the Earth passing in front isn't problematic. For example, if we had 2 HSTs, the viewing time needed for such distant objects would be effectively cut in half.

GCNRevenger · 2004-08-15 22:46:19

It is a problem for interferometry though. Unless both telescopes have simultainious view of the target, then the whole system won't function. Putting it into LEO, with its partner suitably far apart for good resolution, will be obscured too much of the time. Further, the apparent distance between the telescopes to the target should remain fairly constant for easy imaging, but with the constantly changing angle of LEO that is impossible. High orbit, preferably lagrange orbit, is a requirement for it to be worthwhile. This is one reason why basing the telescopes on the slowly-orbiting Moon is such a good idea, because they won't be moving relative to eachother much other than the slow movement of the Moon.

Finally, using multiple telescopes from multiple angles to gather light from one target for one image doesn't provide the linear improvement in light gathering time I don't think, and "mating" the two images would unavoidably add error and blurriness I imagine. And whats wrong with a long exposure for a space telescope? There is DEFINATLY not enough money to build a brand new scope' AND fix HST, so it really is one or the other.

Grypd · 2004-08-16 06:50:37

When MIR was on its last legs I remember that the general foreign consensus was it was a mistaken image of national pride to keep it. I tended to agree with that suggestion but with the MIR it eventually became impossible to solve all the problems and it was deorbited. It has left a bitterness in the Russian space program when it deals with other countries.

It is now the time for the Hubble to be in this situation. I believe it has become a matter of national pride for the Hubble to remain in orbit. It is inconceivable in an Election year for any administration to order its destruction, they cannot allow the political damage to occur.

It may be that the Hubble's use as a science platform can be done better by ground based systems, But that will have little to do with the reason to keep the Hubble. On another thread we are calling the ISS a white elephant but the same reason to keep it is the same reason that hubble will be kept. Politics.

Of course this all relies on being able to "rescue" it before it is too late and that leads to another part of the strategy. Politics mean they cant just do away with the Hubble but if they cant rescue it as they have nothing available to do the job then that is just tough.

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#126 2004-08-11 14:05:10

Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

#129 2004-08-11 19:28:22

Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

#131 2004-08-12 05:30:39

Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

#133 2004-08-12 08:11:57

Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

#140 2004-08-14 05:34:59

Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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Re: Hubble mistake - Action needed

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