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Herschel Space Telescope Opens For the First Time
davecl writes "The Herschel space telescope, the largest ever launched into space, has opened its instrument cover, allowing its three instruments to observe for the first time. BBC news has the main coverage, while there is more coverage on the SPIRE instrument team website, and on the mission blog. I'm part of the SPIRE instrument team and the excitement as we move towards our first observations is building fast. The PACS and SPIRE instruments will see first light in the next few days."
In an effort to contribute something to the thread that isn't irrelevant, stupid, or hateful assholery, this is very cool. I'm looking forward to its first images. Maybe it'll be sensitive enough to image extrasolar planets.
"I disapprove of what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall, re Voltaire
The entry should clarify that it is the largest infrared telescope ever launched. Actually, the adjective large should not be used. Space is not porn. To most people.
It would also be very helpful for the public to know how will Herschel and Hubble complement each-other. Otherwise, the general public may believe that humanity has launched two different things to accomplish the same task.
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I wonder if they designed any of it to be repaired in space, learning from Hubble. (It's not a direct competitor to Hubble because it "sees" in longer wavelengths.)
I wonder if it would have been cheaper to build *multiple* Hubbles rather than repair them in space, which costs about a half-billion per mission. However, they'd have to decide that path in advanced to take advantage of bulk assembly procedures. Or build them to be remotely serviceable thru a repair-bot? But that's mostly untried technology, which usually means expensive or unpredictable overrun risk.
Table-ized A.I.
While not completely obvious from the wording, the slow motion video that most sites seem to be using of the lid opening is actually from a test on an identical cover after it had been sealed for 2 years and not from the actual telescope in space. On the actual telescope, opening was only initially confirmed via gyro sensors and temperature changes afterwards. It won't be fully confirmed until they do light tests.
I couldn't agree more with this statement.
With the dwindling funds that space programs are receiving these days, it is a wonder that we can even send probes into space any more.
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Just as the Hubble happened to be flying by...
Sleep your way to a whiter smile...date a dentist!
I was really bummed when the Beagle rover went MIA years ago... so good for ESA, this is a great accomplishment!
Why do they make Hubble and Herschel sensitive to infrared light? I would think it most important to pick a spectrum that will provide the best information (i.e. instruments should be sentitive to gamma rays if you are looking for gamma ray bursts from supernovae); if that is their criteria, how does infrared help them see what they are looking for?
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I'm not sure who "we" is here, but note that it is mostly a European project, not a US one. It's good to see more international missions because it means more science and different ways of approaching designs and management. Russia's Keep-It-Simple and incremental improvement approach to manned-mission designs have been a fine lesson for NASA, for example. Hopefully NASA will learn new tricks from others' unmanned missions also, as they are learning from our stuff. Plus, more science.
Table-ized A.I.
Perhaps we should ask some Japanese to get some because today, it is tomorrow there.
Questions question questions. Hopefully someone who's been keeping up with event is reading. This is exciting stuff!
;)
I'm curious how far out this will be in comparison to Hubble. Is this in a Lagrange Point? The articles I'm finding via Google just note the distance but don't say much else about it.
Also, will the longer wavelengths give it a better chance of imaging through dust? What effect will it have on the images produced as opposed to Hubble?
Finally, given it's about a meter larger in diameter for the mirror, do they expect that this one will be able to actually image exoplanets? I seem to recall a blip of a story that Hubble 'may' have been able to actually image an exoplanet, but from what I recall, it was almost like a pimple on the edge of a solar disc. Exciting to people in the field, but visually it left something to be desired
Thanks
Infrared can pass through dust, such as that which composes nebulae, that would block other wavelengths.
"I disapprove of what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall, re Voltaire
There are several good reasons to concentrate on infrared radiation. A few, off the top of my head, are: the relative transparency of the interstellar medium in the infrared compared to optical and UV; the optical design of infrared telescopes is closer to that of the familiar optical types compared to X-ray and gamma-ray telescopes; the presence of strong emission lines in the infrared from ionization species unavailable in the optical; the fact that UV and optical emission from distant objects is seen in the infrared due to their high redshifts; and that the thermal emission of circumstellar dust peaks in the infrared. Similar lists exist for the other bandpasses, but screw them :)
Good reasons for placing infrared telescopes into space include the high opacity of the Earth's atmosphere in the infrared, the high thermal emissivity of the Earth and atmosphere in the infrared, and the low temperatures at which the detectors need to be kept.
"I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain
Why do they make Hubble and Herschel sensitive to infrared light? I would think it most important to pick a spectrum that will provide the best information...
Exactly. What spectrum you pick depends on what information you want to get.
Infrared is good for a lot of things. Dust clouds are mostly transparent to infrared, for example, so the infrared is good if you want to look, say, at the nuclei of galaxies (such as our own galaxy) which are surrounded by dust. And if you want to look at galaxies at high redshifts, which is to say, far away (and hence far back in time), infrared is good because the light is shifted into the infrared. Infrared is good at looking for planets, since they emit in the thermal infrared. And many other things.
But if you want to look at gamma-ray bursts from supernovae, no, probably infrared isn't the right way to look. You might want to try the Fermi telescope instead.
There is no one "right" spectrum frequency. They each offer different information; different clues. For example, an animal that can see 3 colors has more potential information than an animal that can only see 1 or 2.
And while Hubble and Herschel may be able to overlap somewhat, they are specialized (optimized) for different frequencies. It's difficult to make a single scope that can see every frequency well, so they send up different scopes for different spectrum ranges. Different materials make for better reflectors, conduits, and sensors for different frequencies. That's just life on the Spectrum Highway.
Think how AM radios need a long wire (coiled in practice) for an antenna. FM radios and traditional TV need about a meter-long antenna(s), and cell-phones have about a 3-inch antenna. No single antenna works best for all. Same with light-based scopes.
Table-ized A.I.
It's all optical, from 200 nm to 2000 nm.
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"Largest" is simply poorly qualified. There's lots of different metrics that they could be referencing, such as weight (of the whole probe), aperture of light-gathering reflector/lens, and total energy of light/radiation it's able to collect and/or process per unit of time from a typical or reference target. Dollars/Euros spent also, for that matter.
Table-ized A.I.
The atmosphere is a lovely IR absorber. So, if you're gonna launch a telescope into space, why not look at a band of frequencies you can't see thru the atmosphere? Whatever you see, it'll be something you can't see from the ground (more or less).
So that works pretty well, if the criteria is to see whats never been seen before, discover new things, etc.
http://en.wikipedia.org/wiki/Infrared_astronomy
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
I was tired of looking for water on Mars. Now we can finally see the Herschel factory!
Now who's being ethnocentric?
I assumed GP meant "we" as in "humanity". Of course, now some asshat will accuse me of speciesism.
Fascism starts when the efficiency of the government becomes more important than the rights of the people.
Or singularists accusing you of pro-pluralist bias. Can't win :-)
Table-ized A.I.
The article mentions the long delay for opening the hatch to wait for outgassing to occur, so the sensors won't get contaminated.
But, don't the pyrotechnic bolts which held the hatch closed (which the article also mentions) outgas, and perhaps even send metallic fragments flying? There is obviously some explosive process involved.
I understand they're more reliable than mechanical latches, but given the need, wouldn't a solenoid operated latch have been better? The hatch would have held closed on its own until in space (since it contained a vacuum), and there's presumably not a lot of force needed to release the hatch once in space.
"National Security is the chief cause of national insecurity." - Celine's First Law
Being speciesist isn't bad, you just have to know which species to not like, and no humanity is not a good choice.
Anything can be found funny, from a certain point of view.
Space is not porn. To most people.
I beg to differ, maybe you just don't hang out with those people because they wants tentacles?
The entry should clarify that it is the largest infrared telescope ever launched.
...and perhaps also that there may well be larger telescopes looking down than up.
It is actually the largest telescope every launched into space. It has a larger mirror than Hubble. It is also true that it is the largest infrared telescope launched into space, but then a square is also a rectangle.
Launched by us as in earthlings?
Unfortunately competition has been the primary funding motive for space programs world wide.
Gaseous or not, an explosion produces residue. A solenoid produces none.
"National Security is the chief cause of national insecurity." - Celine's First Law
I shouldn't expect people to actually read the articles before commenting.
The Herschel was designed and built by the ESA, not NASA and the JPL. JPL had nothing to do with it.
"National Security is the chief cause of national insecurity." - Celine's First Law
According to Wikipedia:
At 3.5 meters wide, its telescope incorporates the largest mirror ever deployed in space.
It's also important to note that there are fields other than porn in which size matters. In this case, the size of the mirrors in a telescope is proportional to the quantity of light it can focus to its sensors, and thus proportional to its sensitivity.
The entry should clarify that it is the largest infrared telescope ever launched. Actually, the adjective large should not be used. Space is not porn. To most people.
The kid's never seen an an open elliptical galaxy. Heh.
to boldly look where... no... man... has looked... before!
"Same with light-based scopes."
Not to be pedantic, but all electromagnetic radiation is light, just not the way we're use to hearing it used.
Infra-red light is still light. 802.11 radiation is still electromagnetic radiation. Whether it's an AM radio in an old car, a $400 cell phone, or a telescope in the sky, it's all the same medium.
if that is their criteria, how does infrared help them see what they are looking for?
Night vision, you clod. Astronomers sleep during the day. Why do you think the astronomical Julian day begins at noon?
am i the only curmudgeon who thinks telescope PR should start with 1st light ?
Cover opening doesn't actually mean anything is working - when they have images that are within spec being sent to earth on a regular basis, they have a working scope
Yes, to look for things like missile launches and %$^%@#$# CARRIER LOST
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
I couldn't agree more with this statement.
With the dwindling funds that space programs are receiving these days, it is a wonder that we can even send probes into space any more.
Just FYI: http://www.nasa.gov/home/hqnews/2009/may/HQ_09-102_FY2010Budget.html
That's a 5% increase for those not interested in link clicking.
I am not sure if "light" has a technical definition. Generally when one says "light", they mean either the visible spectrum (to humans), or frequencies close to it. That's what common usage dictates.
Table-ized A.I.
Actually measuring the aperture in wavelengths of light observed by the instrument might be even more meaning full; an instrument like Herschel that observes in the deep infrared need a larger aperture than Hubble to get the same resolution.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Of course, now some asshat will accuse me of speciesism.
Silence, you insensitive clod -- I'm an asshat.