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Space Science

Infrared Telescope Lifts Off 127

Posted by Hemos from the up-up-up-and-away dept.
An anonymous reader writes "On its Delta 2 Heavy-Lift vehicle, the Space Infrared Telescope (SIRTF) successfully launched to its solar orbit at 1:35 AM (EDT). As a result of the expansion of the Universe, most of the optical and ultraviolet radiation emitted from stars, galaxies, and quasars since the beginning of time now lies in the infrared. How and when the first objects in the Universe formed will be learned in large part from this observatory's infrared observations."
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Infrared Telescope Lifts Off More

Infrared Telescope Lifts Off

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  • Oh no! (Score:2, Funny)

    by briancollins ( 700695 )
    Now they can catch me speeding from outer space!
  • So as we try to see farther and farther, we need to get more infrared pictures. And we need to send bigger and bigger fridges into space with bigger cameras inside.

    Soon they'll try the ultimate, using the recent MIT laser cooling technique to bring down the temperature to below 1 kelvins. Now thats when the ambient cosmic background radiation will become a pain.

    Ive photographed in the night, and I know you need to keep the shutter open for up to a minute or more. I wonder if those giant freezers can hold
    • I wonder if those giant freezers can hold still as they orbit around a planet that orbits around the sun.

      SIRTF will be in an Earth-trailing heliocentric orbit.

    • They will soon be needing LONG exposure times.

      Judging from Hubble, long exposure times will not be a problem.

      • FYI: The longest HST single HST observation I found was a GHRS spectrum at 230,414 seconds. The longest NICMOS (infrared) exposure was 3839 seconds. It's rare to do a single long exposure. Most of the time, exposures are split and stacked, usually to clean out the cosmic rays.
        • FYI: The longest HST single HST observation I found was a GHRS spectrum at 230,414 seconds.

          One of the recent deep field frames had an impressive exposure time. Ah, I found it I think - only 153,700 s. Still, quite a while. ;-)

          • That wasn't a single exposure, it was a combination of exposures that added to 153,700 sec. That's actually how the deep fields are done. So you don't have to hold the telescope steady for that long (although it pretty much is anyway).

            • That wasn't a single exposure, it was a combination of exposures that added to 153,700 sec. That's actually how the deep fields are done. So you don't have to hold the telescope steady for that long (although it pretty much is anyway).

              Given the way CCDs operate, any long exposure is typically made up of many shorter exposures. You are correct in that the telescope may not be pointed continuously over the entire exposure.

    • Re:Digital Cameras in freezers on rockets. (Score:4, Funny)

      by FrostedWheat ( 172733 ) on Monday August 25, 2003 @09:11AM (#6783670)
      They will soon be needing LONG exposure times.

      As long as they can point accuratly, it shouldn't be a problem.

      Things in space inevitably drift a little, but the beauty of digital cameras is that you don't have to do the exposure all at once. You could pause, re-aim the telescope then begin again.
    • Isn't it cold enough in space already? What benefit is gained?

      • Re:Digital Cameras in freezers on rockets. (Score:5, Informative)

        by Betelgeuse ( 35904 ) on Monday August 25, 2003 @09:18AM (#6783737) Homepage
        Actually, it can get pretty damn hot with the Sun up there. If the satellite were out of the solar system, then it is true that cooling wouldn't be much of an issue. But, with the Sun right next door (astronomically speaking), it's very important that you have good cooling. In fact, this will only be a 2 year mission, due to the fact that the cooling system (liquid helium, I believe) will only last for that long. . .

        • Re:Digital Cameras in freezers on rockets. (Score:1, Informative)

          by Anonymous Coward
          I worked on this program, and actually, there are many many pains taken to extend this mission. There is a very good chance that the mission will last way longer than 2 years.

          You'd be amazed at the meetings debating kinds of black paint.... A lot of tiny details were sweated to optimize this lifetime. Electronics that do the data compression and spacecraft control are all situated way far away from the detectors/dewar so that the heat put off by the electronics will have less warming effect on the dewar
      • Space is not cold enough to cool down the elements surrounding the camera so that they are essentially "invisible" to it. If you need evidence, take a look at what happened when the cooling on Hubble's IR cam (NICMOS) ran out prematurely. NICMOS was completely useless until it was serviced rather recently, because it was constantly saturated by the infrared light emitted from the surrounding instrumentation.

        I'm no physicist, so I may not have the terms right in my explanation, but you definetely need coo

      • Technically, space itself is cold around here, yes... but only because there isn't much in the way of matter to heat up. That also means there isn't any physical medium of significance to transfer heat to kinetically, so you can only radiate heat away.

        Effectively, this means that if your spacecraft is directly exposed to a radiant heat source like, say, the sun, and you are fairly close to it, you have a serious need to dump heat from the far side if you want to stay frosty.

        • They had a long explanation on this on the BBC last night. The helium is bled off to wick away heat, but they didn't say anything about the orbit or placement of these things. Seems the earth's shadow would be a good place as over two years it should be able to view pretty much everything twice.

          Prepare to be underwhelmed by images though as they'll probably the the spotty or smudgey things astronomers whoop with joy over and say, "Nyah! Dark Mass, told you so!" But just aren't visually appealing enough

          • I believe that orbital speed and orbital distance are related - so if you managed to get the satellite into orbit about the Sun in the Earth's shadow, it would have a year that was longer than ours and would fall out of the shadow into direct sunlight anyway.

            • It gets better. (Score:2, Insightful)

              by mindstrm ( 20013 )
              Around any pair of orbiting bodies are what we call the Lagrange points... points of relative stability where gravitational forces balance out.

              L2 is, I believe, opposite the Sun on the other side of earth... I am unsure if it would be in shadow, as I'm not sure of the distance... but something sitting there will have a year the same length as the earth.

              This is due to the earth's gravity added to the suns.. effectively something at L2 feels like it's orbiting a heavier mass, so it can orbit faster to keep

              • I'm sorry, but I refuse to accept anything as a fact when it's cited by someone who believes in planet X.

                Actually, I'm not sorry.

                And I believe only 2 of the 4 Lagrange points are 'stable' for the purposes of parking anything there for a long time. The points leading and trailing earth in its orbit are the most stable, which is why they will tend to hold small debris for fairly long periods of time.

      • The electronics turn electrical energy into heat, and the fact that a large part of the satellite will be trying to collect energy (ie solar panels) means that there will be heat. Any heated object will give off emissions that show up as noise in the IR spectrum. It is actually rather difficult to cool objects in space as there is no matter to transfer the heat to...the energy must be radiated. So refrigeration is needs to pull the heat away from the IR detectors to radiators, thus minimizing the noise a

      • Thanks for all the responses! You've shed a lot of light, on heat.

        :-)

    • No refrigerators here. Closed cycle refrigerators capable of reaching cryogenic temperatures are big, bulky beasts with prohibitive power requirements. Furthermore, they tend to induce vibrations, which aren't generally good for precision photography.

      Of course, I'm talking about more conventional cryostats. The laser cooling methods that the poster referred to are only relevant for gas phase atoms.

      Instead, the telescope launched with 360 liters of liquid helium. It will last 5 years. When the helium is
    • ... for people to start doing research with. Since universe as we know it has been expanding since the "beginning" of time, there have been new theories that suggest that at some point, that process would stop and the universe would bgin to contract, and eventually cave in on itself. Technology like this IR machine-robot-vehicle can give us more accurate results to relevant physical questions like:

      What is the density of the universe (our solar system)?

      Where does it end, when does a new one start?

      Is th

    • Re:Digital Cameras in freezers on rockets. (Score:5, Informative)

      by wass ( 72082 ) on Monday August 25, 2003 @09:48AM (#6784018)
      You don't need laser cooling to get below 1K.

      Using a simple pumped He3 system, which we just set up in our lab last week, you can easily reach about 300 mK. You use a pumped He4 bath to surround your insert, keeping it at about 1.5 K, and then pump the He3 with a charcoal sorb, to get to 300 mK. In space, you can use blackbody radiation to cool you to the ambient temperature of space (I forget whwat it is, somewhere between 3 to 7 K), and then use He3 pumping to go colder.

      You can also get to about 10 mK if you use a dilution regridgerator, which uses a mix of He3 and He4 and relies on changes of entropy as you add them together, and then separate them out.

      However, this all assumes that the highest CCD's need to actually go this low. But if for some reason this is needed, these refridgeration techniques are much more efficient and easier than laser cooling. Laser cooling is when you need to go COLD, like microKelvins.

      • I stand corrected on the numbers.

        You're right about the practical cooling methods we might use soon, but as the visual distance gets longer, for lower wavelengths we might need VERY cool CCDs, unless we have to move to radio arrays.
      • Doesn't that require evaporation? I seem to recall from college chemistry that the reason pumping works is due to evaporative cooling. Kind of like a liquid helium swamp cooler. I would think that it'd be hard to get useful evaporative cooling in space due to that whole vacuum thing.
        • I seem to recall from college chemistry that the reason pumping works is due to evaporative cooling.

          It sounds like he's just talking about straightforward refrigeration: pump a refrigerant to a low pressure, and it boils, absorbing heat from whatever you want cooled; then pump it back up to a high pressure, and it condenses, dumping the heat somewhere else. The refrigerant never actually gets used up unless there's a leak.
    • Well the cooling of the cameras are to make the readout noise lower and to remove the ambient infrared radiation all warm things give off. Much of the instruments optics need to be cooled more than any laser cooling of individual atoms can accomplish (just a thermal mass problem). Hence the refrigeration system.

      And as for the ability to hold it still, the Hubble has a near infrared camera, NICMOS, that is cooled the same way. It has both gyros and optical instraments watch for drift and large momentum

      • Indeed; SIRTF will be great in the short term, but for real longevity (including upgrades to the instrumentation as technology advances), it's going to be hard to beat SOFIA [usra.edu]. The ability to service and upgrade a facility is what kept HST useful for so long. With SOFIA, we're effectively dealing with an observatory that lands every day. By comparison with space based observatories, improving and upgrading SOFIA will be a snap!

    • Soon they'll try the ultimate, using the recent MIT laser cooling technique to bring down the temperature to below 1 kelvins. Now thats when the ambient cosmic background radiation will become a pain.

      SCUBA (Submillimeter Common-User Bolometer Array) on JCMT [hawaii.edu] maintains a temperature of about 60mK using a liquid helium dilution refrigerator. It is probably the continuously coldest place that we know of in the universe, since it maintains 60mK for weeks on end.

      So no, you don't need laser cooling techniques to

  • Ball Aerospace Link (Score:5, Informative)

    by evilninja ( 261516 ) on Monday August 25, 2003 @08:37AM (#6783447)
    I work at Ball Aerospace... I thought some of you might like to see the BATC stuff [ball.com].

  • Picture (Score:1, Funny)

    by rf0 ( 159958 )
    Am I the only one who thinks that the SIRTF looks a bit like a high-end coffee machine?

    Rus

    • Re:Picture (Score:3, Funny)

      by macrom ( 537566 )
      No, but I am wondering where the 'F' came from.

      On its Delta 2 Heavy-Lift vehicle, the Space Infrared Telescope (SIRTF)

      Bob : So, uh, whaddya think we should call this thing. I mean, it's just a Huge Infrared Telescope.
      Jim : That's brilliant! HIRT! Haha! Everyone will laugh at our clever naming scheme.
      Bob : Yeah, but the heads of the program will never go for it. How about SIRT? Space Infrared Telescope?
      Jim : Hmm, don't you think 4 letters in an aerospace acronym is soooo cliche? Can't we make it 5 le
      • Well, I'll admit it's a bit of a stretch, but there ARE several different instruments on board. So, to some degree, it is a "facility".

        On the other hand, these are the same people who named an X-Ray telescope after a theorist. But not even the theorist's full name; they used his nickname.

        • Re:Picture (Score:3, Funny)

          by Talez ( 468021 )
          His nickname? Ray?
          • Heh. Yes. I probably should have specified. The "Great Observatory" that is looking in the x-rays is the Chandra X-Ray Observatory (or something like that). It's named after Subrahmanyan Chandrasekhar, who was called "Chandra."
      • No, but I am wondering where the 'F' came from.

        It means "Facility". On Mauna Kea NASA operates an (obviously ground-based) infrared telescope called IRTF, which stands for Infrared Telescope Facility. They slapped the "Space" on SIRTF to differentiate between the two.

    • Well, both are basically vacuum bottles. But, while the coffee pot is trying to keep the inside hot, SIRTF's helium dewar is trying to keep its innards very, very cold.

      See: this article in Space Today [spacetoday.org] on SIRTF.

      • According to that article, the SIRTF is shuttle-servicable - "SIRTF is a long duration facility serviceable by a space shuttle or from the manned space station.".

        This seems to require that it's in a fairly low Earth orbit, not in a solar orbit at all.

        What's the story?

  • A good article about SIRTF (Score:3, Interesting)

    by fuqqer ( 545069 ) on Monday August 25, 2003 @08:53AM (#6783555) Homepage
    I posted this as a news story yesterday. It was rejected.

    Anyway,

    Here's [spaceflightnow.com] a nice article about SIRTF that I found to be pretty cool.

  • Excellent development (Score:4, Insightful)

    by Ompaloskeptic ( 697688 ) on Monday August 25, 2003 @09:00AM (#6783600)
    This is great. The more telescopes we can get in orbit, the better. Especially those in different spectrums. There's so much data that the earth is being bomarded wioth constantly that is untapped. We're slowly getting more and more of this data and leaning so much about the universe because of it. I lok foward to the findings of this telescope.

  • 60 years (Score:5, Interesting)

    by solarlux ( 610904 ) <noplasmaNO@SPAMyahoo.com> on Monday August 25, 2003 @09:03AM (#6783621)

    God, I hope they calculate the trajectories right or there might be an interesting "meteor" shower in about 60 years...

    CNN Article [cnn.com]

    Unlike most astronomical spacecraft SIRTF will not be orbiting the Earth. Instead, it will be put into orbit around the sun. "SIRTF will be following the Earth around the sun, kind of like a faithful puppy dog," astronomer Michael Werner said. The solar orbit increases the lifetime of the spacecraft. SIRTF will gradually lag further and further away from the Earth until it's too far to be detected. But in about six decades the Earth will "catch up" with SIRTF, like a race car lapping another race car.
    • Someone correct me if I'm wrong, but I believe that SIRTF is a relatively small satellite (i.e. the type that would be likely to burn up in the atmosphere and not reach Earth). And remember, the first "Great Observatory" (Compton) did re-enter the atmosphere, without any big problems.
    • SIRTF will be following the Earth around the sun, kind of like a faithful puppy dog," astronomer Michael Werner said.

      We'll be fine as long as it doesn't try to hump the Earth's leg!
    • The same article mentions that the craft has enough coolant to last it ~5.5 years. So what the hell is the point of having it come around again in 60 years?
      • Too bad, because I would have loved to see NASA extend its life by launching a tiny and cheap 'repeater' satellite to pickup and relay its distant signal...

    • This is a smart plan for a sattelite such as this where temperature is critical. I've been working on some thermal simulation code for the ISS program, and in addition to direct solar heating, heat radiating away from the Earth and albedo (sunlight reflected off the Earth) are big factors in heating. Unlike sunlight however, these other two depend directly on distance from the Earth. Move further away and you get less heat.

      Of course, it also helps that this telescope is only intended to work for a few

      • Or it comes back in a couple of hundred years looking for whales.
      • After 30 years, the telescope will be on the opposite side of the sun, so even if it was still working, you would need other sattelites to relay the signal.

        The odds of us not launching relay sats in a similar solar orbit in the next 30 years is very low, so we'll know if it's still working when behind the sun if we're still here and still interested in antiques.

        --

  • Some other projects along the same lines.... (Score:5, Informative)

    by supermojoman ( 699985 ) on Monday August 25, 2003 @09:38AM (#6783917)
    Here are some links to other projects that have similar goals - examining expansion of the universe, faraway objects, etc. They also have sophisticated infrared imaging capabilities. The James Webb Space Telescope [stsci.edu] (formerly Next Generation Space Telescope) is the successor to Hubble, and Supernova/Acceleration Probe [lbl.gov] which, from what I remember, locates potential supernovae by examining data taken at fixed ground locations then points an orbiting camera at the calculated location to collect radiation data. Really interesting stuff!

  • Technology (Score:5, Informative)

    by ZenArchitect ( 701321 ) on Monday August 25, 2003 @09:39AM (#6783938) Homepage
    As a member of the team that is building the ground system for the science center that will be the primary interface between the public and the telescope I'm happy to say that code is all Java based. We have managed to combine the best that the open source community has available with a couple of commercial products to be a very productive development team. Here is a sample of what we are developing:
    • "Thick" Java Client for proposals, planning and data retieval - yes folks, Java on the desktop does work
    • Estimating and visibility servers - many computing drone managed by a J2EE server
    • Web services access to all of the public data produced by SIRTF - Perl, .NET, C++ is doesn't matter you can all get the data
    Oh, I forgot the mention.... there is not a single Windows box in the operations system. It's all Unix based because... well you know why don't you?

  • From the CNN.com article [cnn.com]:
    SIRTF's detectors are incredibly sensitive. If you could put a common household television remote control in deep space SIRTF could detect it at a distance of 25,000 miles.

    Considering that taxpayers put up 1.9 billion for the observatory, do you think they could use it to find the remote cotrol that I lost in my living room?

  • It is worth noting that the SIRTF SWIRE survey [caltech.edu] may be able to detect solar system sized supercomputers, aka Matrioshka Brains [aeiveos.com]. For discussion see the thread starting here [javien.com] and navigate using the icons in the upper right hand corner of the screen.

  • Lifts off? (Score:1, Redundant)

    by _ph1ux_ ( 216706 )
    Wouldnt it be the "infrared telescope extends into space"

  • Think of a name... (Score:1)

    by Anonymous Coward
    Hubble.. Compton... Chandra etc. Given that nearly all science probes are named after famous scientists, and clearly no-one got round to nominating one for SIRTF, who does the Slashdot crowd believe this probe should honour?


    Perhaps Cmdr Taco should tell Nasa who we select?


    No answers on a post card, please...

    • Hubble.. Compton... Chandra etc. Given that nearly all science probes are named after famous scientists, and clearly no-one got round to nominating one for SIRTF, who does the Slashdot crowd believe this probe should honour?

      William Herschel.

      He was the first true infra-red astronomer. He used a prism to cast a spectrum of sunlight and then measured the heating effect on the blackened bulb of a mercury thermometer. He was surprised to discover that the heating effect grew greater as he moved towards th

  • Anyone else hear the liftoff announcer?

    I mean I understand it is a high stress job, but he made George Bush sound like a confident and interesting orator....

    Dubyah has better script writers to.

    Q.

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