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Science

Recycled Satellite Yields Scientific Treasure 37

Posted by Roblimo from the Arthur-C.-Clarke-could-have-written-this-one dept.
Rob (not Malda) sent us this story about how UC Berkeley astronomer Derek Buzasi found that a satellite with a malfunctioning main telescope had a perfectly functional "spotting" scope that could still be used to gather valuable data. Now, because of Buzasi's inspiration, the Wide Field Infrared Explorer (WIRE) satellite NASA had written off as a $73 million piece of space trash is a useful astronomical tool that makes approximately 750,000 observations per day.
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Recycled Satellite Yields Scientific Treasure More

Recycled Satellite Yields Scientific Treasure

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  • Try looking at stars in the daytime ;-)
  • I'd guess it's more a bandwidth problem than a computational one. In other words, simple calculations on a huge pile of data, rather than intensive number-crunching on a small packet.

    Still, it would be interesting to offer, and I'd gladly drop RC5-64 for this project.
  • distributed.net would love to tackle some more scientific projects, unfortunatly, our current network isn't readily adaptable to most of these endeavors. We are having a tough enough time setting things up for OGR, let alone a project that would require moving large amounts of data around. }:8(

    BUT, we are always looking for future projects! }:8) So, if you are involved with a scientific endeavor that you think a network of 70,000+ machines could do useful work on, please feel free to contact me directly at decibel@distributed.net. (Please, only contact me if you have direct contact with a project.)

    Mooo!
    dB!
  • Hey! We want to help! The man said that he's drinking from a firehose of data.

    We have a little idea about how we can help you analyze the information. See if you can get distributed.net to take your project. Some of us wanted to be scientists when we grew up, but we became computer programmers instead. That doesn't mean that we ever gave up the dream. I'd love to contribute cycles to this project.

  • How much does one cost? Roughly.
  • It is my understanding that a faulty computer chip had a bug in it that caused a cover over the dewer to be released too early during launch. This unfortunately, heated the dewer and the hydrogen cryogen then vented at a relatively extreme rate. Since the cryogen is completely vented, the detector cannot be cooled. The detector must be cooled in order to measure the low amounts of radiation that it is intended to measure.

    I don't know if their web page [caltech.edu] is official or not, but it has many pictures. Actually, I could have saved the typing as the first entry (1999 March 29) describes the failure. So read it there.

    ~afniv
    "Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"
  • This topic has really gotten me thinking about how distributed computing can apply to astronomical data analysis. Unfortunately, as someone mentioned above, actual astronomical observations can require some massaging by hand, so distributed analysis is less than straight-forward. This is the case with WIRE, for instance.

    However, numerical simulations could be pretty easy to distribute. My current simulations of starburst galaxies take about 10 hours to crunch on a quad processor (296Mhz x 4) ultra w/ half a gig of ram. I'd like to run, say, a million of these per galaxy I'm studying, but this is entirely unfeasable with the computing resources I have available to me.

    I've already started talking with my advisor about distributed computing for our simulations. The seti folks really have the right idea here. I'm surprised nobody else in the astronomical community has taken advantage of this yet....

    -zeno
  • I know Derek (the scientist in question) pretty well. I'll pass the distributed suggestion along to him. However, the last poster was right - it's large ammounts of data and relatively simple computations. I'm sure he could think of some good distributed projects if others are interested, though.

    This is actually something I'd never considerred. I've got very processor-intensive simulations of starburst galaxies which would make a great distributed project.....

    -zeno
  • WIRE was only intended to be used for 4 months because of the cooling issues that another poster has already explained.

    They couldn't have even hoped to have a repair mission up there within the 4 months that they were originally working under.

    Again as another poster pointed out the cost of the repair would have been much more than what it cost to build.
  • Does anyone know more about the "little known bug in a computer chip" ?

  • It's great that there is some use for this otherwise floating piece of junk. However, the article, to my recolection, doesn't mention why the main scope can't be repaired. They hacked the hubble back together, why not do something similar for WIRE?
  • Why not repair the WIRE?

    Because the Hubble repair missions go for at least $300M a shot, not including the new instruments they use for upgrades, beyond simple repairs.

    Would you want to pay $300M to repair a $73M satellite?
  • "Darned clever these Earthlings..."
  • IIRC, all spacecraft are launched into a west-to-east orbit to take advantage of the Earth's rotational energy at launch. So correct me if I'm wrong (it's been a few years since my astronomy class) but wouldn't everything orbiting at the same altitude be traveling at roughly the same speed in the same direction?

    I think it's not the space junk so much as the rogue micrometeoroids that you have to watch for. (Not that that makes the situation much better.)
    --

  • Now if only somebody could find a "perfectly functional" use for M$ products.
  • If this guy can dig up some good pieces from a otherwise junk sattelite, I wonder what other stuff is up there that we could use? It wouldn't have to be the cream of the crop stuff, just the things that NASA has written off as end of life. I bet we could get quite a trove of data off of some of the still working stuff.
  • The reason WIRE cant be repaired is because it lost all its frozen hydrogen into space, and without that the infrared camera will just be taking a picture of a warm lens instead of the heat eminating from 'out there'. To repair it it would require going up there, cracking it open and putting new frozen hydrogen inside which would cost more than the satellite itself cost to make. Someone was meantioning opening up the project, couldnt work here but it got me thinking about something else. Why hasnt anyone built some sort of standardized interface for this? You could have something akin to the dead idea of push technology but it would allow you to donate certain amounts of processing power to projects you find worthwhile. In screensaver mode then, you could donate 25% of your processor's time to SETI@home, and 75% of your processor's time to crunching the math for rendering the latest disney film, cryptography, number crunching star-burst galaxy data, etc. Sounds like a cool idea if you ask me.
  • There ought to be some regulations that specify that all sattelites going into orbit have a small seperate booster for reentry and burn up. If the sattelite fails or has gone past its usable life this could be activated removing it from our debris field. We also ought to develop a "clamp on" solution that the shuttle could take up and send a couple old pieces of junk back to earth with. Just light fuse and get away. I'm sure for larger stuff this would be unfeasable but all the small dead sattelites and junk up there... there has to be a solution.

    Man this Chineese food is good today.
    However Yesterday's Microsoft FUD gave me indigestion.
  • It's nice to see that the $73 mil that was spent on the satellite isn't totally going to waste. It constantly blows my mind when I hear about all the junk that is floating around up in the near orbit. Heck, it's a wonder they can even put anything else up there with all the satellites and debris that's flying around...
  • The problem is not with the material large enough for this to work with. The problem is with the material that is too small to even track, such as paint chips and naturally-occuring micrometeorites.
    Christopher A. Bohn
  • The problem is it's not that simple. Add in orbital inclinations and eccentricities, and we no longer have a collection of bodies that pose no possible threat to each other.
    Granted, in most conceivable scenarios, there won't be a "head-on" collision (the only conceivable scenario would be two bodies in near-polar orbit), but you don't need to have a "head-on" collision to cause damage.
    Christopher A. Bohn
  • Plans for shuttle operations out of Vandenberg were canned when the DoD decided it wasn't going to rely on the shuttle for its launches. SLC-6 has since been turned into a commercial launch facility.
    Christopher A. Bohn
  • ... reducing astronomical data often can't be sped up by throwing more processors at the job. The Seti system is a case where the data reduction is straight forward, so it can be distributed easily. However, an astronomer often has to make adjustments to the data analysis process by hand, for each target or each set of targets, depending on the observing conditions and what you'd like to know about the target.

    Perhaps the sort of data their getting from all their targets is similar, and can be reduced using the same method. Perhaps, though, their looking for different things from different targets, so a general enough distributed method that is convenient for the astronomer is difficult to design.

    I'm glad people would like to participate in distributed data reduction and scientific computing. I think it's a heck of a lot more useful to society that cracking one of an infinite set of code keys. :) I'm sure scientists will start to ask for your help more and more over the next few years... and maybe, depending on the methods involved, this will be one of next distributed projects.

    Hope this sheds some light on things!

    John
    -
  • The telescope itself is working perfectly, but it isn't cold enough.

    There's two things that I can think of, and I'm not sure which applies here. Maybe both of these reasons apply.

    The first is keeping the photon detectors cold enough so that electronic noise doesn't wipe out the image. If you've read about sidewinder missles that track heat from airplanes, then you would have read that they carry a store of a cryogenic fluid (liquid nitrogen??) to cool the detector. That's because at room temperatures there's enough energy to cause atoms in the detector to jump back and forth between high and low energy states. Looking at that on a display would be like looking at a snowy picture. Cooling the detector down stops that random jumping around, and atoms only move to the higher energy state when a photon hits them. The picture would be cleared up.

    The second reason is that the telescope itself emits infrared radiation, and that emission from the telescope itself would cause the image to be washed out completely. If you can cool the telescope down with liquid hydrogen then the very very faint infrared sources won't be washed out by the heat from the telescope. As an analogy, imagine how bad the image would be if you mounted flashlights inside an optical telescope and tried to look at stars. You wouldn't see anything.

  • This is an obvious plug. We're a small company and don't have our named mentioned all that often. The star tracker (as it is really called) was built by Ball Aerospace [ball.com]. It is the Ball CT-601 [ball.com] model tracker with a 7.5in shell and 92mm lens, so I'm told.

    Our trackers [ball.com] are used all over the place, so perhaps other spacecraft can be used similarly.

    Needless to say, our star tracker folks are excited.

    ~afniv
    "Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"
  • It's undoubtably super news that there is an aspect of the satellite that may prove useful. Having any telescope in space, even one as small as this spotting scope is astonishly great for calibrating ground-based telescope observations which need to be made through miles of crud in our atmosphere.

    But while this is a small improvement on what would have been a total loss, it is certainly not going to be free. For every active satellite (or even any active ground-based telescope to a lesser extent), there is a substantial expenditure in maintainance and data processing. For a satellite a large part of the price comes from ground operations, including issuing commands and maintaining a downlink station to receive the data as it comes in.

    More information for the confused: Why is a tiny telescope (2 inch diameter) in space such a big deal? After all, anyone could pay about $200 and buy a telescope from a department store with equivalent light collection power. The key is that any telescope in orbit is above terrestrial weather. Measuring stellar brightness and color (which in turn yield info about a star's age, mass, distance, etc) is difficult from the ground because the atmosphere is not transparent. Weather makes the transparency change on short timescales, so a star's brightness appears to change rapidly. This is especially difficult for an astronomer who wants to study stars which have intrinsically variable brightness.

    In short, a little satellite-borne telescope is a stable instrument for consistent work, like all those 386's running Linux and serving web pages out there.
  • It's amazing how bad the space trash problem is getting up there. And every little speck of debris is a serious problem.

    Every time the Space Shuttle goes up, they have to replace the glass, and many of the panels, due to collisions with tiny particles. Even something the size of a grain of sand can cause a visible pit. A 1" screw in a head-on collision could possibly cause a hull breach.

    Remember that everything in orbit is going about 16,000 mph. A head-on collision means that screw would be hitting at 32,000 mph. An article in a recent Smithsonian went into detail about how they are designing armor for the International Space Station to try and withstand this - they've developed, for this purpose, a very high velocity gun that can shoot a projectile at about 25,000 mph. At this speed, a 1/2" diameter sphere will blow a head-sized hole in 1-inch steel.

    Personally, I'm amazed at the fact that astronauts will still go on space walks. The microdebris alone could easily kill them.


    ---

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