Forgot your password?
typodupeerror
Space Science

John Mather On the Building of the James Webb Space Telescope 78

Posted by Soulskill
from the i-can-see-my-house-from-here dept.
Nancy Atkinson writes "Why is the James Webb Space Telescope (scheduled to launch in 2013) taking so long to build? Hasn't it had a huge cost over-run and several delays? Nobel Prize winner John Mather is the Project Scientist for JWST, and he addresses these questions and more in an in-depth interview, one of the few he's given about this next-generation telescope and successor to the Hubble Space Telescope. Quoting: 'The hardest thing to build was the mirror, because we needed something that is way bigger than Hubble. But you can't possibly lift something that big or fit it into a rocket, so you need something that is lighter weight but nonetheless larger, so it has to have the ability to fold up. The mirror is made of light-weight beryllium, and has 18 hexagonal segments. The telescope folds up like a butterfly in its chrysalis and will have to completely undo itself. It's a rather elaborate process that will take many hours. The telescope is huge, at 6.5 meters (21 feet), so it's pretty impressive.'"
This discussion has been archived. No new comments can be posted.

John Mather On the Building of the James Webb Space Telescope

Comments Filter:
  • Why not build this thing in space? Either in orbit or, if the lack of a planet for infrastructure is too hard (or too premature for our skills), build it on the Moon and then launch it into Earth orbit from there. The microgravity of orbit, and the near zero atmosphere (especially in orbit) or just the lower gravity of the Moon, should allow more defect-free building. And building in space seems to offer easier and cheaper testing, with the real environment right there.

    It seems to me that they could build r

    • by PPH (736903) on Saturday March 21, 2009 @12:06PM (#27279329)
      Because tooling and equipment needed to build it weight many orders of magnitude more than the telescope.
      • by Doc Ruby (173196) on Saturday March 21, 2009 @06:37PM (#27282933) Homepage Journal

        And for the next 20 telescopes? Vastly bigger and better than any we can build to launch from Earth?

        How about the rest of the space industry, like pharmaceuticals, other zero-G/vacuum manufacture, and solar energy collectors, all for returning products to Earth. How about a Lunar base and factory from which to make and launch the rest of what we launch across the Solar System, including to Mars, and outside to interstellar space? A network of comms satellites for science and eventual travel, and perhaps industry among the other planets.

        Especially solar power collectors/transmitters would be the next step after we understand the basic science behind space industrial engineering. The value of that, both in the energy and its geopolitical benefits (security, peace, minimal pollution, the pride of getting our of our energy/pollution dead end), is worth quite a lot of investment. Especially with an American or American-led brand on it.

        This is the gateway. We are standing on the threshold of projects that are starting to be better performed in space, with the technology to do it. The first project is going to cost way more than that project will return directly. But it will get us started on the much bigger project of industrializing space, with its incalculable returns.

        Or we can plod along. And let the military define space industrialization instead of consumer products and energy. Or let rivals like Russia, China or Europe do either - or both - while we're stuck in the 20th Century, in which we made the investments that got those rivals started to pass us.

        • Re: (Score:3, Insightful)

          by PPH (736903)

          Assembling big things in space is a possibility. The ISS is an example. But we need to put people up there to do anything more than the simplest jobs. And we can't even keep our manned programs up to date.

          The reason we got stuck with the aging shuttle is that there was no economic justification for the program in the first place. And as a result, no basis upon which to do a cost-benefit analysis (like when airlines scap their L1011s and buy 777s).

          Anyway, even when such an analysis is done, its always going

          • by Ihmhi (1206036)

            What we need is for someone to invent Gundanium Alloy already.

          • by Doc Ruby (173196)

            If the Moon had a solar energy base powering manufacturing, that would be great competition to Earth manufacture. Especially once Earth manufacture shows its true costs, especially in pollution.

            And that solar energy base could send power back to Earth, replacing terrestrial fuels or real estate consumed by wind, solar, hydroelectric and other alternatives.

            There is going to be a point where our investment in space energy and manufacturing pays off hugely. We're already probably at a low plateau for our launc

    • by ogre7299 (229737) <`jjtobin' `at' `umich.edu'> on Saturday March 21, 2009 @12:07PM (#27279333)

      The problem with this idea is that you will have to send people to put it together. And you still need to launch all the pieces.

      So you'll have combined cost launching the pieces and people. Whereas building it on earth, you have all the engineers to put it together and then put it up all in one shot.

      Until there is a manufacturing base out in space which probably will not happen for a long long long time, you still have to design and test everything on the ground. This is because you can't afford to launch a faultly part, this is true if you are sending the whole thing up or putting it up in pieces.

    • by khallow (566160) on Saturday March 21, 2009 @12:07PM (#27279337)
      1. We don't know how to do that yet and we don't have the infrastructure to support it. Lunar manufacturing facilities capable of building state of the art telescopes are well beyond our reach.
      2. If assembly in orbit, all material would be supplied from Earth. Too expensive at near future launch costs.
      3. Not enough demand. Only one space telescope.
      4. Requires a lot of testing and inspection by humans on site.
      5. Lunar manufacture of telescopes not much of an improvement over Earth-based manufacture. Same gravity problems. There is some benefit to putting stuff in Earth orbit with lower delta v and no Earth atmosphere to interfere. But a space telescope would be a high value per weight item and hence something that can be competitively lauched from Earth.
      • Not enough demand. Only one space telescope.

        That's not a problem. Once this is built, other projects will present themselves.

        • Not enough demand. Only one space telescope.

          That's not a problem. Once this is built, other projects will present themselves.

          It's a problem for whomever is tossing the money around to fund these projects.

        • Re: (Score:3, Insightful)

          by khallow (566160)

          That's not a problem. Once this is built, other projects will present themselves.

          And these projects are? The "build it and they will come" argument doesn't work in the complete absence of any knowledge of demand for this sort of thing.

          • Once we have the ability to build things like this, we can, among other things, build space probes in orbit. This simplifies things because they don't have to have the ability to deploy. It also cuts the mass because all of the equipment used to deploy is used exactly once, but is carried for the rest of the mission. It also means that the probe itself doesn't have to be sturdy enough to withstand launch forces, and that the various components can be reinspected and, if needed, have any launch damage cor
            • Re: (Score:3, Informative)

              by khallow (566160)

              Once we have the ability to build things like this, we can, among other things, build space probes in orbit.

              Why would we want to do that?

              This simplifies things because they don't have to have the ability to deploy. It also cuts the mass because all of the equipment used to deploy is used exactly once, but is carried for the rest of the mission. It also means that the probe itself doesn't have to be sturdy enough to withstand launch forces, and that the various components can be reinspected and, if needed, have any launch damage corrected before it sets out.

              I don't think this is well thought out. You are weighing the cost of building a satellite in space versus Earth-side manufacture with some special deployment. The latter will win in any near future cost evaluation. It doesn't help that a lot of applications can't get rid of the requirements either for nontrivial deployment processes or high thrust trajectories (see the Oberth effect [wikipedia.org]).

              • It doesn't help that a lot of applications can't get rid of the requirements either for nontrivial deployment processes

                You missed the point completely: you build the probe already deployed, so that the motors, gears and levers needed to deploy it can be left out. This means fewer moving parts, less points of failure and a simpler design. It also gives us practice in building things in space that can be used if/when we want to construct interplanetary space ships up there. Remember, LEO is half-way to a

                • by khallow (566160)

                  You missed the point completely: you build the probe already deployed

                  Yes, sometimes you can do that. Sometimes you can't. And you still ignore that at least for the next few decades, it'll be cheaper to build on Earth than to build a somewhat simpler design in space.

                  • And you still ignore that at least for the next few decades, it'll be cheaper to build on Earth than to build a somewhat simpler design in space.

                    No, I'm not ignoring it, I'm thinking long-term. I'm also thinking of space-probe construction as one of the things we can do once we have a permanent manned presence in orbit rather than as the main motive for us getting that permanent presence.

      • by VagaStorm (691999)
        Or just wait 5 years until the Chinese have a space dock for their mass manufacturing of the peoples satelite "defenders", and rent it....
        • by khallow (566160)
          You're going to have to wait a lot more than 5 years. China isn't moving fast enough to warrant that level of optimism.
    • Re: (Score:3, Informative)

      by Cally (10873)
      Look at the size of that thing [northropgrumman.com]. (Seriously, it's absolutely bloody enormous [nasa.gov]; that's a scale engineering model, with handy nearby humans for scale. Yes, those little black dots on the ground around it are humans... ;) )
    • by skoda (211470)

      Because that is impossible. We do not have spaceborn manufacturing facilities, period. Not for paperclips and tennis shoes, much less for a novel space telescope.

      There have been interesting proposals for lunar telescope manufacturing facilities, but that is science fiction for now.

      • by Doc Ruby (173196)

        Er, we'd build those things. And not overnight. Who gave you the idea that I was asking NASA to look up "giant space telescope factory in space" in the Yellow Pages or something?

        We don't need a space factory for paper clips. But especially since big telescope mirrors are now evidently hard up against manufacturing limits we have here on Earth, but are looser in space, we should get started doing it where it's better done.

  • Correct me if I am wrong, but isn't the James Web Space Telescope only gathering light in spectra beyond the visible light range? If so, it's not really a replacement for Hubble.
    • Re: (Score:3, Informative)

      by Cally (10873)
      Well, it's infra-red, but that's pretty close to the spectra of visible light, so the images it produces will be closer to the visual appearance than they do in, say, X-rays. You might also be thinking of the Compton [wikipedia.org], Chandra [wikipedia.org] or Spitzer [wikipedia.org] space telescopes, which are part of the same programme [wikipedia.org] that gave us Hubble, but are all sensitive to different wavelengths.
  • by wisebabo (638845) on Saturday March 21, 2009 @12:08PM (#27279357) Journal

    So, when the JWST was designed Orion (and the launch vehicles Ares I and Ares V) weren't on the drawing boards.

    Does anyone know if Orion will be able to service it? Since it's being designed for flights to the moon, L2 isn't that much further away is it? So the amount of supplies it needs to carry shouldn't be a problem and the reentry capsule should be able to handle the 25,000 mph return. However would the mission be too dangerous in terms of radiation exposure?

    Have provisions been made on the JWST since to allow for removal/change of the instruments/gyroscopes like Hubble? What about docking ports or grappling interfaces?

    • by khallow (566160)
      My take is not a chance. First, it's in the L2 Lagrange point of the Earth-Moon system (that's the unstable equilibrium past the far side of the Moon). That's out of reach for the base Orion spacecraft with no additional launches. You need multiple launches to reach L2. For example, NASA's Constellation approach to reach L2 requires two launches, one Orion on an Ares I and propellant and mission gear on the heavy lift Ares V. There are ways to put together a mission using Ares I-class vehicles, but these r
      • by wisebabo (638845)

        thanks, also the previous poster (why is the comment hidden) pointed out the wikipedia article on the JWST but it said amongst other things servicing provisions are still under consideration (2008).

        My big fear is that the launch doesn't go successfully, having a multi-billion dollar spacecraft dependent on a foreign launch vehicle makes me nervous. Maybe that's why they fought over the launch decision to use the (free) Ariane V for two years. I'm very happy Kepler went off okay very unhappy about the Orbi

        • by John Hasler (414242) on Saturday March 21, 2009 @01:22PM (#27279911) Homepage

          > ...having a multi-billion dollar spacecraft dependent on a foreign launch vehicle makes
          > me nervous.

          That's silly. Ariane V is just as reliable as anything the USA has that could launch the JWST. This is not some Russian war-surplus ICBM or Chinese knock-off of an old US design. It is a mature modern rocket with an excellent launch history.

          • That's silly. Ariane V is just as reliable as anything the USA has that could launch the JWST. This is not some Russian war-surplus ICBM or Chinese knock-off of an old US design. It is a mature modern rocket with an excellent launch history.

            Russians are lucky then that Proton with its very good track record is no "Russian war-surplus ICBM" but a solid piece of dedicated launcher engineering work. :]

        • Re: (Score:3, Informative)

          by khallow (566160)

          thanks, also the previous poster (why is the comment hidden) pointed out the wikipedia article on the JWST but it said amongst other things servicing provisions are still under consideration (2008).

          From Wikipedia:

          NASA is considering plans to add a grapple feature so future spacecraft might visit the observatory to fix gross deployment problems, such as a stuck solar panel or antenna. However, the telescope itself would not be serviceable, so that astronauts would not be able to do things such as swapping out instruments, as has been done with the Hubble Telescope.[18][19][20][21] Final approval for such an addition will be considered as part of the Preliminary Design Review in March 2008.

          That's not a serious effort to make the JWST serviceable.

          My big fear is that the launch doesn't go successfully, having a multi-billion dollar spacecraft dependent on a foreign launch vehicle makes me nervous. Maybe that's why they fought over the launch decision to use the (free) Ariane V for two years. I'm very happy Kepler went off okay very unhappy about the Orbiting Carbon Observatory.

          You do realize that rockets have different capabilities and reliability? The Ariane V is one of the more reliable rockets out there. So is the Delta II that launched the Kepler mission. If you wanted to launch the JWST, currently, you'd need to use either a Proton (can be launched from Kourou, I think), Ariane V (also from Kourou), or Delta IV Heavy (from Cape Canaveral Air Force Station). I don't think other rockets have the payload ca

        • by khallow (566160)
          I glanced at the poster you mention. He's an "anonymous coward" poster. Those posts start at 0 by default. The post is hidden from you by your slashdot settings. You can change them to read posts at 0 or above, assuming you want to chew through that many posts.
    • Does anyone know if Orion will be able to service it?

      Have provisions been made on the JWST since to allow for removal/change of the instruments/gyroscopes like Hubble? What about docking ports or grappling interfaces?

      No and No. The Earth-Sun L2 point that the JWST will operate at is 1.5 million kilometers away, where the moon averages around 400k kilometers away. Not that the Orion has any grapplers to grab onto the JWST anyhow. Nor does Orion have an airlock to allow for safe spacewalks - the entire craf

  • by skoda (211470) on Saturday March 21, 2009 @12:18PM (#27279435) Homepage

    Those who denigrate aerospace projects for being over budget and over schedule are either naive or disingenous.

    The unfortunate reality is aerospace companies are strongly motivated by the Federal Gov't proposal selection process to bid too low and too fast for high-risk projects like JWST. While not truely "lowest cost" bidder selection, it's understood that a winning bid will be in a certain range, regardless of whether its realistic. And the schedule proposals must also target certain bogies to have a chance of winning, regardless of winning.

    And so companies bid low and fast to meet the proposal expectations and requirements, knowing that they'll make it up in cost-plus overruns as the Program proceeds.

    And those running the programs know this too.

    And ultimately, each project such as JWST is a one-of-a-kind endeavor. New technologies, new manufacturing methods, new test techniques are invented during the course of the project. It's difficult to predict the budget and schedule for doing something never done before; much less keeping to an optimistic budget driven by political needs more than the technical.

    To those on JWST, they are doing incredible work, putting in long hours, and coming up with creative solutions to very challenging problems. And everyone of them wants to see JWST succeed.

    • by khallow (566160)
      While you are relatively accurate as far as such things go, it's worth noting that there are very few fields of private endeavor where cost plus contracts are common (eg, law) and these contractors have an efficient campaign contribution system by which they can legally bribe the people who control the money for these contracts.
    • by syousef (465911)

      Those who denigrate aerospace projects for being over budget and over schedule are either naive or disingenous.

      You left out a 3rd possibility: That they are stupid - drooling inbred moron stupid.

    • The unfortunate reality is aerospace companies are strongly motivated by the Federal Gov't proposal selection process to bid too low and too fast for high-risk projects like JWST.

      You'd have a point if that was how the JWST was being built, JWST is being built by NASA, not contracted out.

      • by khallow (566160)

        You'd have a point if that was how the JWST was being built, JWST is being built by NASA, not contracted out.

        That is how JWST is being built. As I recall, TRW is the primary contractor overseeing construction. Ball is the contractor for the optics systems. Not sure who else is involved.

  • No comment? (Score:5, Insightful)

    by gammaraybuster (913268) on Saturday March 21, 2009 @12:21PM (#27279461)

    I had to reply to this thread, seeing only 9 hidden comments so far. That's a bit sad, since the JWST will be one of the most important science events since the Hubble. It will be an infrared telescope like the Spitzer, but it will effectively be an optical telescope for the distant universe because of red shift! And it will be able to peer into the distant past unlike any telescope prior.

    In the sense of being a "space race" this is one area where the US really shines. There's no other nation that really is in the running, although there are lots of international contributions (yay Canada!). Maybe it's because of the language barrier, but I can't think of a single Russian space telescope. I can name a half dozen US scopes and one or two from the ESA. (Be sure to look up the Chandra [harvard.edu], Fermi [nasa.gov], Spitzer [caltech.edu], XMM-Newton [esa.int])

    But then it's not really a space race, it's about science, so maybe it's a little boring for the general public. I only hope Slashdotter's are more aware that this is one of the great scientific adventures of our time.

    • by Cally (10873)
      ...don't forget [slashdot.org] Kepler [nasa.gov]!
    • Re: (Score:3, Interesting)

      by Jeff DeMaagd (2015)

      I recall that India, China and Japan have ongoing lunar orbiter missions right now, Japan having an HD feed to earth, I've heard there is a real-time satellite channel that retransmits that feed to any household that tunes to that channel. I can't say much for Russia, I don't recall much from them. Russia gets a lot of money from oil and gas, and the prices aren't what they were in the past couple years.

      Hubble may have been a bit too successful, Hubble images have entered mainstream culture in a way few o

    • by MrKaos (858439)

      I only hope Slashdotter's are more aware that this is one of the great scientific adventures of our time.

      Seems like one of the most exciting things NASA has done since launching HST. That it is being launched by a European Launcher lends a spirit of co-operation that is something we need to see more of if humanity is to get off this rock.

  • <sarcasm>

    Isn't the Japanese space elevator supposed to fix this problem?

    </sarcasm>
  • I'm disappointed in the James Webb telescope because:

    a) it will be shooting in infrared and that means no visible light details of the planets in our solar system, no pictures of asteroids. Yes, it will help us see stuff billions of light years away, and that's interesting, but what's going on in our solar system is pretty relevant. The easiest way to fix that, of course, is to build a solar system space telescope. Compared to bailing out a bank, I'd much rather have another space telescope.

    b) it's named after a bureaucrat, not a scientist. To me, the JWS is right up there with the USS Carl Vinson, John Stennis, and any of the US warships named after presidents. It's just pathetic and sends all the wrong messages.

    For christ sakes, if we are going to name it after anybody. I would even prefer naming it after a golden era sci fi writer - Bradbury, Asimov...

    • it's named after a bureaucrat, not a scientist. To me, the JWS is right up there with the USS Carl Vinson, John Stennis, and any of the US warships named after presidents. It's just pathetic and sends all the wrong messages.

      Yeah. Afterr all the guy who all but built NASA from the ground up and who steered NASA through the Apollo years can't possibly be an important figure.

      • by tjstork (137384)

        Yeah. Afterr all the guy who all but built NASA from the ground up and who steered NASA through the Apollo years can't possibly be an important figure.

        Still a bureaucrat. Doesn't deserve it.

        • IOW "my mind is made up, don't confuse with facts, I prefer mindless bigotry".

        • by lennier (44736)

          "Still a bureaucrat. Doesn't deserve it."

          In what way is "bureaucrat" a swear word to you?

          *Someone* has to do the hard and creative work of running organisations. Some people are really gifted at this and do it well. Those who do, contribute hugely to science and society.

    • it will be shooting in infrared and that means no visible light details of the planets in our solar system, no pictures of asteroids.

      There are plenty of giant telescopes on Earth that operate in the visible spectrum. With adaptive optics their images are comparable to those from Hubble. We'll still be observing Solar System objects in the visible spectrum, don't worry about that.

      However, no amount of optical trickery can compensate for the fact that the Earth's atmosphere is opaque to infrared. If we wa

      • by tjstork (137384)

        With adaptive optics their images are comparable to those from Hubble

        My point is that even from Hubble, Pluto is a handful of pixels. We really need a bigger space telescope for visible to keep tabs on the solar system.

        we make sure that what they see is something that we absolutely could not see from the ground.

        We can't see Pluto from the ground, either.

        • by Morty (32057)

          We have already seen Pluto from the ground. Adaptive optics rock that way. Here is an article with pictures. [msn.com]

          Even more importantly, adaptive optics is a relatively young technology that is getting better. As the GP said, JWST is really expensive. JWST also won't be ready for launch for years yet. It doesn't make sense to pour massive money into a space telescope for visible light when we can already beat Hubble from the ground under some conditions, and we're getting better.

          Note that, thanks to New Hor [jhuapl.edu]

  • My God, so much potential, so much risk. Close to 20 years of work, and billions of dollars, and then it'll be sent to the L2 point, millions of miles away from earth, where no one can ever go to fix it. And once it arrives, it'll have to self-assemble. The Mars rovers seemed like high stakes, but there were two of them, and we've had similar landers before and after. But compared to the JWS, I don't think there's anything comparable... or is there?

    I sure hope this works right the first time.
  • It is a business with no competition. The customers can't just stop paying for it. That would be called tax evasion.

  • NASA is taking a long time with this scope because even though they already have rockets, and astronomers, and huge mirrors, and space telescopes, and orbital mechanics, they had to invent ANOTHER technology for this one:

    space origami with glass

Real programs don't eat cache.

Working...