Change In Experiment Will Delay Shuttle Launch 64
necro81 writes "A $1.5 billion gamma ray experiment, the Alpha Magnetic Spectrometer, that was to have launched aboard the space shuttle Endeavor to the International Space Station in July, has undergone a last minute design change that will change the launch date, pushing back the end of the shuttle program by at least several months. The change replaces the original liquid helium-cooled superconducting magnet with a more conventional one, which will reduce the risks involved (superconducting magnets can be problematic — just ask CERN) and will greatly extend the useful life of the spectrometer (the liquid helium coolant would have boiled away within a few years of launch). Although the conventional electromagnet is only 1/5th as strong, its increased lifespan should allow for substantially more science to be conducted, especially considering the ISS's extended mission life. As the change is still underway, the impact to the final shuttle schedule is not fully known."
Re:Oh please (Score:4, Insightful)
Um, please remind me, how did they orbit the Hubble?
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There was no reason to use a manned launcher to orbit the Hubble.
For the cost of the repair mission and all the other worthless manned flights they could have put up 10 Hubbles.
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Ten Hubbles that wouldn't have worked properly because of the optical defect. Having a temporary repair platform shouldn't be necessary, but it sure was handy in this instance.
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Nobody said they had to launch them all at the same time. Could have been 1 that didn't work and 9 that did.
Even more sobering: if the above cost analysis is correct, it could have been 9 that didn't work and 1 that did, and we'd be no worse off.
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The above "cost analysis" was hyperbole pulled out of the poster's ass. Your delicious understatement of the benefits of having 9 simultaneously operational Hubble telescopes only underlines the hyperbole. No worse off? Try fantastically well off. Astronomers would be giddy for months for the chance to gain access to such an armada.
I'm not especially pleased by the ridiculous expense of the Shuttle, or the welfare for engineers that it represents, but on the other hand I believe that any organization no
Seriously? (Score:5, Interesting)
IAASIE (I am a space instrumentation engineer) and I really find such a major last minute decision hard to believe, seeing how long and detailed the flight model / integration tests are...
Re:Seriously? (Score:4, Insightful)
Re:Seriously? (Score:4, Interesting)
IAASIE (I am a space instrumentation engineer) and I really find such a major last minute decision hard to believe, seeing how long and detailed the flight model / integration tests are...
Maybe they are actually swapping one validated unit for a different validated unit.
Re:Seriously? (Score:5, Informative)
Yeah, according to Wikipedia, they are indeed swapping the cryo-cooled superconducting electromagnet for the conventional one that flew on the AMS-1. Reading the AMS website, I found out that both have the same dimensions and mechanical interfaces to the instrument, since they were developed as swappable alternatives for short- and long-lived mission profiles. However I think the overall working of AMS-2 has still changed enough (especially with the removal of the cryogenic circuitry and the change in magnetic field) for the whole integration and testing process to be redone from scratch.
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Re:Seriously? (Score:5, Funny)
They're waiting for the second-chance offer to come up on ebay.
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This experiment has been in development for over 12 years (since AMS 1 flew in 1998).
Re:Seriously? (Score:5, Insightful)
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I also find it hard to believe that someone would name a spectrometer designed to measure gammas the "alpha spectrometer."
Re:Seriously? (Score:5, Informative)
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Thanks, that makes lots of sense!
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IAASIE (I am a space instrumentation engineer)...
Quiet peon, and bow to the administrator! [flexes pencil like arms]
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It is the National Air and Space Administration
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Re:Seriously? (Score:5, Interesting)
Re:Seriously? (Score:4, Interesting)
Doubly so since the cryogens aren't the only limit on the experiment's lifetime. There's also the gas supply for the photomultiplier tubes, whose expected life I cannot find anywhere.
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I prefer to tall this phenomonon VAES Syndrome (Verbose Acronym Explaination Syndrome... Awww crap).
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I think that Dr. Ting and his associates should get tuned in to reality. This is the second time around for this experiment. They are holding up billions of dollars in tax payers money for a launch that was prepared a long time ago. Life has to go on. Maybe they should look else where to get this thing to ISS? Perhaps one of the unmanned cargo flights?
If they can't be on this bus then find another way. Why should things get held up because they can't make up their minds?
But does it run Linux? (Score:5, Funny)
If only it ran Ubuntu, then we'd know what's the Shuttleworth.
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If only it ran Ubuntu, then we'd know what's the Shuttleworth.
Actually, the firmware for the original was written by a famous kernel dev [wikipedia.org], which explains why early headlines stated:
SHUTTLE COX BLOCKED
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Contingency plans for X37B? (Score:4, Interesting)
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Having a different inclination actually puts X37B out of reach of Endeavor or any Shuttle-ISS flight. These are completely different missions with no plans for any interaction between them.
Regarding your skepticism about the destruction of USA 193, I refer you to Jim Oberg's excellent summary here [jamesoberg.com]
Re:summary is wrong (Score:4, Insightful)
Submitter is a moron who does not know what he is talking about.
If you're going make that sort of statement, you could at least:
1. Offer up some evidence to back up your statement. A link would do.
2. Sign your fucking name to it.
Thank you,
The Internet
High-temperature superconductor magnets? (Score:5, Interesting)
Re:High-temperature superconductor magnets? (Score:5, Informative)
There are a few reasons: 1) high temp superconductors have a relatively low critical magnetic field strength at liquid Nitrogen temperatures and 2) At this point, switching to high tempt superconductors in the design would require an even longer delay due to the testing required. Of course if 1/5 the field strength is a ok then high temp superconductors should still have a sufficient critical magnetic field strength at liquide Nitrogen temperatures. Although really, you'd still have coolant boiling away just at a somewhat slower pace.
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High temperature superconductors generally can't produce big magnetic fields without the superconductivity breaking down. They're fine for carrying big currents in straight lines, but they make terrible magnets. That's why the LHC's magnets are low temperature superconductors, even though this isn't a space application which had to be planned 20 years in advance.
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Space itself is cold, yes (high vacuum means there are very few particles to vibrate, so low temperature). HOWEVER, the solar radiation heats objects up rather nicely. If solar radiation didn't heat things, we'd be frozen here on earth too. To keep this instrument cold by exposing it to space would require a giant sun shield.
Re:Space is cold (Score:5, Informative)
Space isn't actually cold. There's nothing there to be cold. In order to transfer heat, you need something to transfer it into, and there's just nothing there.
See this [irregularwebcomic.net] excellent discussion of cooling problems for the Star Wars planet-city Coruscant.
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Let's not swap one absurdity for another. Space is extremely cold, at about 3K. Poor heat transfer is an orthogonal issue, which prevents you using space as a heat sink. If a device is generating its own heat or picking it up from (solar) radiation, it will heat up. If it's inert and in the shade, it will get cold and stay cold.
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If an object radiates away all its energy because it's in space, it doesn't get cold because space is cold. It gets cold because there's nothing there to radiate energy back into the object.
You can say that the stuff in space that isn't just empty space has a temperature, but it's so spread out that radiation becomes the dominant mode of heat transfer, and it has such little mass and is so cool that its black body radiation is meaningless. It is effectively not there for this interaction.
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No. Your model is of an object in an infinite, unbounded void, a void which would indeed have no temperature to speak of. However that is not the universe. Any subset of the universe exchanges heat with the remainder, and would do so even if radiation was the only mechanism of heat transfer. Therefore thermodynamics allows that we can - and must - talk about the temperature of space in a sensible way.
If you take an object and you place it in the universe in a cavity which (for the sake of discussion) is lar
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Any significant rate
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It is a galaxy populated by sword fighting space wizards. Is a plausible explanation strictly necessary?
NOT gamma-rays (Score:2, Informative)
Experimental Gamma Rays (Score:1)
The case for intact equipment return (Score:5, Interesting)
AMS is one of the poster children for a capability that will be lost with the retirement of the shuttle, a capability many insist we don't need - intact equipment return.
The original plan was, when the cryogens ran out, to return AMS to Earth and rerun the pre launch calibration checks (essentially using a particle accelerator to shoot particles through the AMS) - not only allowing us to learn about the effects of the orbital environment, but also being able to apply the knowledge of those effects to the analysis of the science data collected on orbit.
1,5 billion dollar experiment? (Score:1)
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What kind of experiment are we talking about (/should i have read TFA for) here?
They're going to fire large amounts of nickles and dimes into the sun from a cannon disguised as a telescope to see exactly how much metal is needed to stop the fusion reaction and cause a supernova. The delay is being caused by some guy who forgot to bring exact change, and now he's holding up the queue by arguing with the cashier why he can't just put in a dollar.
But really, something with cosmic radiation, particle of the week, and magnets. A typical plot used in modern scifi, only with the added realism
azizajalal (Score:1)
!gamma rays (Score:1)
Someone really needs to fix the summary because it is NOT a gamma ray experiment at all. It is a cosmic ray experiment that detects baryonic matter (protons and small nuclei).