SOFIA, a Telescope On an Aeroplane That Has Been Scrutinized For Years, To Shut Down (nature.com) 39
NASA and the German Aerospace Center are permanently shutting down the Stratospheric Observatory for Infrared Astronomy (SOFIA), a telescope on an aeroplane that has been scrutinized for years for its high cost and low scientific output. From a report: Since 2014, the observatory has made hundreds of flights above the water vapour in Earth's atmosphere to get an unobscured view of celestial objects and to gather data at infrared wavelengths. SOFIA has measured magnetic fields in galaxies1, spotted water on sunlit portions of the Moon2 and detected the first type of ion that formed in the Universe, helium hydride3. But it costs NASA around $85 million a year to operate, which is nearly as much as the operational expenses for the Hubble Space Telescope. On 28 April, NASA and the German Aerospace Center, the two partners in SOFIA, announced that they will close down the observatory by 30 September.
Competition (Score:5, Insightful)
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> immediate needs
What examples of immediate needs are there when observing celestial bodies that are billions of years old?
Re:Competition (Score:4, Insightful)
> immediate needs
What examples of immediate needs are there when observing celestial bodies that are billions of years old?
If something happens, such as a hypernova [wikipedia.org] in a nearby galaxy. We could learn much with a telescope that can quickly swing into position to observe.
JWST can only look at half the sky. You have to wait six months to see the other half.
Re: Competition (Score:4, Insightful)
SOFIA was/is only useful for observing the night sky, so itâ(TM)s Field off observation isnâ(TM)t much different than JWST.
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Maybe this plane could be stationed like bombers at the height of the cold war: Sitting 24x7 at the end of a runway, gassed up with crew strapped in, and ready to scramble within seconds in response to any enemy hypernova.
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Asteroids.
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Typically, th
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Also, airplanes have pretty intense maintenance needs. This cuts greatly into the effective observation times.
Re:Competition (Score:5, Informative)
SOFIA observes in the 0.3 to 1600 m wavelength range.
JWST (the Webb) observes in the 0.6 to 28.3 m wavelength range.
So there is an entire wavelength range that is NOT covered by the Webb.
The larger issue here is: science, and especially astronomy, is cash-starved, and thus it is necessary to choose wisely which projects to fund. If astronomers had the option, both projects would be kept operational; but this option does not exist (as can be promptly seen by the fact that a large fraction of the astronomy work is actually performed by postdocs, who are used as "cheaper" labor, as there is a worldwide lack of resources to hire more permanent researchers and faculty).
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in my post above, "m" should obviously read "um" in the wavelengths (where u = mu; but the Greek character was not accepted by slashdot system).
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Slashdot has non-ASCII character handling that would embarrass a 1980s Pascal program (the last formal programming training I had ; I know of what I speak), as befits a system programmed in the late 1990s after the introduction of Unicode.
I've got to admit that this is one of the more complex decisions. Not that Slashdot attempts anything more complex than "Ugggh, ASCII ! Ugggh !!! [chest thumping]"
[WIKI https://en.wikipedia.org/wiki/... [wikipedia.org] ] The official symbol for the SI prefix micro- is a Greek lowercase mu. In Unicode, there is also a micro sign with the code point U+00B5 (Â), distinct from the code point U+03BC (μ) of the Greek letter lowercase mu. According to the Unicode Consortium, the Greek letter character is preferred,[12] but implementations must recognize the micro sign as well. Most fonts use the same glyph for the two characters.
Does "& micro ;" work? No.
Doe
Aeroplane (Score:2, Funny)
Troubled program (Score:5, Informative)
SOFIA was meant as a stopgap until Spitzer came online. But huge delays in its construction meant it only got off the ground in 2007, 4 years after Spitzer launched.
In a good year, SOFIA will do 800 hours of observation. Any space telescope will do 8760 h/year.
SOFIA is installed in a 45 year-old Boeing 747SP, one of the last 4 SPs still flying. It has a D inspection coming up.
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Why? with the JWST it's obsolete.
Re: Don't throw it away just because it's old. (Score:3)
Pretty hard to update and/or change the instruments on JWST, while that could be done on a mission by mission basis with SOFIA. SOFIA also has a less restrictive field of observation than JWST.
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Still, I'd have to audit this $85M/year operating costs. Let's see a plane based on a 747-100, the 747SP only had 45 planes ever built so some parts would be hard to find. The crew, I can see that costing $1M/yr, the plane per flight let's say $100K/flight. Say another $10M or so in annual maintenance, tires etc. I still can't see $85M/yr.
While it's made a few contributions to science the fact that they were looking for more publications using the SOFIA instrument says a lot about budgets and usefulness.
Yes
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You've left out, at least, the cost of the planning pipeline (which isn't all done for free by professors in ivory towers, but by instrument specialist technicians on the ground, talking to the professors submitting observation proposals) , and also of the data processing pipeline before redistribution of the calibrated data to the proposal's authors and global databases.
I suspect you're flight crew figure is pretty low too
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>SOFIA also has a less restrictive field of observation than JWST.
How so? Someone else mentioned that SOPHIA can only be used at night, which if true means that it has a very similar observation field as JWST - the half-dome of sky facing away from the sun.
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JWST can't observe a half-dome though. It can spin on the Earth-L2 axis, and it can adjust its angle to that axis by about 40Â. So its field of view is a cylinder with its axis along the Earth-L2 axis.
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Huh, didn't realize it's outward view was limited, I wonder why they didn't put an actuated hinge between the the scope and sun shield? I suppose it's one more system to fail, potentially in a very suboptimal position.
At any rate I think it's not *quite* as limited as you're imagining. Cylinders are a poor visualization aid for fields of view, since they don't offer any bounding faces that extend to infinity the way a spherical sector (or dome) does. A better visualization would be a sphere that had th
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Hmm, though I suppose that's only the *instantaneous* field of view - a ground based observatory can actually look very near the sun shortly after it sets, or before it rises. So over the course of 24 hours an observatory on the equator could see almost the entire sky.
Of course the Webb gets 100% coverage over the course of a year, but there's a whole lot of the most interesting astronomical events where days, and even hours matter, and it's luck of the draw whether those happen within the 40% of the sky t
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Only 5 hours of slewing time and instrument calibration time per year. That's 3-nines performance. I think you'll find it a lot lower than that. Probably better than 5000 hours per year, but I'd honestly doubt claims better than 8000 hours per year.
Yes, SOFIA is less time-efficient than a space telescope, and most ground-based telescopes of comparable size. But it's not as bad as you make out. Needing a crew of operations staff who are also pilots is a major constrai
Moon2? (Score:2)
What and where is "Moon2"? /Will be looking out for Moon2 tonight...
Also, why does it cost $85 million a year to maintain the Hubble Telescope? Does someone have to go up there to give it a good wash once a week?
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Hubble costs include the Space Telescope Science Institute, and a share of NASA's relay satellite system. Observing schedules don't plan themselves.
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Oh? And how exactly could it be done better for cheaper?
Orbital telescopes are *expensive*, and you can't make infrared observations using a ground-based telescope. That leaves airplanes, suborbital rockets, and airships.
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Some infrared observations you can't make from the ground - particularly those looking for readings in the bands where atmospheric water and CO2 absorb large amounts of the incident radiation. The point of SOFIA was that it could get above most of the atmospheric water vapour (water-ice being less of a problem), opening those windows. But leaving the CO2 windows still more or less shut. That's also part of the reason for putting ground-ba
A powerful tool of the occult folks (Score:5, Interesting)
(Disclaimer: I've operated terrestrial telescopes in the 1-8 meter range for almost 20 years, and have numerous friends or former colleagues who worked with/aboard SOFIA.)
The one thing SOFIA could do that no terrestrial telescope could do, and -- to the best of my knowledge -- no space telescope could do either, was position itself basically anywhere on the planet to precisely align with, and follow, occultations. So if a moon of one of the outer planets was going to pass in front of a background star, but it would only appear to do so along a narrow corridor of Earth's surface? Sure, ground-based telescopes might be able to get part of the track -- been there, done that, a couple times -- but SOFIA could fly out over the ocean and get more.
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Yeah, one of the beautiful things about Lagrange telescopes over orbital (or ground/air) is that the planet never gets in their way.
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Thanks very much for that explanation, from someone a lot closer to the entire scene than most of us are. I'd always wondered what SOFIA was good for, really; and now I know a little more. Much appreciated.
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Can't be bothered to remove references4 (Score:2)
[4] Copy and pasted to be fr1st on /.!!!