Sofia, the Historic Airplane-Borne Telescope, Lands For the Last Time (wired.com) 27
An anonymous reader quotes a report from Wired: Over the past eight years, a modified Boeing 747 jetliner has flown hundreds of flights on a unique mission: carrying a 19-ton, 2.5-meter telescope known as Sofia, or the Stratospheric Observatory for Infrared Astronomy. Flying a telescope on a jumbo jet offered a way to peer into the heavens at wavelengths that could not be glimpsed from the ground -- but the ticket was expensive. So yesterday, NASA and the German space agency grounded the mission. Its final flight landed early Thursday morning at NASA's Armstrong Flight Research Center in the desert near Los Angeles.
Sofia was an innovative way to gaze at the infrared universe. Infrared light is essentially heat radiation -- but astronomers can't probe cosmic objects like dust-enshrouded stars and galaxies without the water vapor in Earth's atmosphere absorbing that light. That confounds attempts to observe those objects with telescopes built on mountaintops, like the observatories in Hawaii and Chile. But by soaring through the stratosphere, at an elevation of 40,000 feet or higher, Sofia could fly above that water vapor and get a much better view. "Almost 50 percent of the energy of the universe comes out in the mid- to far infrared. Sofia has played an important and unique role for its lifetime, probing that entire wavelength range, and we've been able to observe all manner of phenomena that were otherwise invisible to other facilities," says Jim De Buizer, Sofia senior scientist at NASA's Ames Research Center in Mountain View, California.
De Buizer and the Sofia team have made a number of significant astronomical discoveries, including measuring cosmic magnetic fields permeating nearby galaxies, charting the growth of massive stars, observing Pluto's faint shadow as it passed in front of a distant star, and even discovering water on the sunlit surface of the moon's southern hemisphere. The data from Sofia's final flight will map stellar nebulas and help scientists study the magnetic fields of the Sculptor starburst galaxy. But while flying a telescope in a jet is much less expensive than launching one aboard a spacecraft, like NASA's Spitzer and Webb space telescopes and the European Space Agency's Herschel Space Observatory, it's still not cheap. There are costs for the pilots, staff, engineers, and mechanics -- plus a round of repairs to the aircraft that had to be made in 2018. Sofia costs NASA about $85 million per year -- a significant fraction of its astrophysics budget. And that's actually only 80 percent of the funding it needs; NASA's German counterparts provided the rest. It was ultimately the mission's high operating costs, relative to its scientific output, that took Sofia down. "At the end of the day, the project itself just wasn't productive. You're talking about almost a Hubble cost for operations, but with a fraction of the scientific productivity," says Casey Dreier, senior space policy adviser for the Planetary Society, a nonprofit research organization based in Pasadena, California.
"I feel for the scientists. They can't control the operational costs," Dreier says. "But Sofia got eight years of operations. It had a good, healthy life, for a mission."
Sofia was an innovative way to gaze at the infrared universe. Infrared light is essentially heat radiation -- but astronomers can't probe cosmic objects like dust-enshrouded stars and galaxies without the water vapor in Earth's atmosphere absorbing that light. That confounds attempts to observe those objects with telescopes built on mountaintops, like the observatories in Hawaii and Chile. But by soaring through the stratosphere, at an elevation of 40,000 feet or higher, Sofia could fly above that water vapor and get a much better view. "Almost 50 percent of the energy of the universe comes out in the mid- to far infrared. Sofia has played an important and unique role for its lifetime, probing that entire wavelength range, and we've been able to observe all manner of phenomena that were otherwise invisible to other facilities," says Jim De Buizer, Sofia senior scientist at NASA's Ames Research Center in Mountain View, California.
De Buizer and the Sofia team have made a number of significant astronomical discoveries, including measuring cosmic magnetic fields permeating nearby galaxies, charting the growth of massive stars, observing Pluto's faint shadow as it passed in front of a distant star, and even discovering water on the sunlit surface of the moon's southern hemisphere. The data from Sofia's final flight will map stellar nebulas and help scientists study the magnetic fields of the Sculptor starburst galaxy. But while flying a telescope in a jet is much less expensive than launching one aboard a spacecraft, like NASA's Spitzer and Webb space telescopes and the European Space Agency's Herschel Space Observatory, it's still not cheap. There are costs for the pilots, staff, engineers, and mechanics -- plus a round of repairs to the aircraft that had to be made in 2018. Sofia costs NASA about $85 million per year -- a significant fraction of its astrophysics budget. And that's actually only 80 percent of the funding it needs; NASA's German counterparts provided the rest. It was ultimately the mission's high operating costs, relative to its scientific output, that took Sofia down. "At the end of the day, the project itself just wasn't productive. You're talking about almost a Hubble cost for operations, but with a fraction of the scientific productivity," says Casey Dreier, senior space policy adviser for the Planetary Society, a nonprofit research organization based in Pasadena, California.
"I feel for the scientists. They can't control the operational costs," Dreier says. "But Sofia got eight years of operations. It had a good, healthy life, for a mission."
Airship? (Score:2)
Sounds like a job for an airship. Maybe we should do some more work on high-altitude airships [nasa.gov].
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My interest in the story was limited, but I'm pretty sure the balloons can't get that high. Maybe hydrogen instead of helium? But then you need to plan for the inevitable fire...
However the JWST is barely mentioned in the summary, and none of the links seem to lead towards answers to my questions about the relative effectiveness of the two platforms. Yes, the JWST is obviously expensive, but the quality of the results and the availability of the instrument is so much superior that I suspect that's the actua
Re:Airship? (Score:4, Interesting)
While there is some overlap between JWST and SOFIA, SOFIA could observe much longer wavelengths than JWST. At least a couple of instruments on SOFIA could do polarimetry, which can be used the to do the magnetic field measurements mentioned in TFS. I'm not an expert, but I don't think JWST can do polarimetry.
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The problem with high-altitude balloons is that their payload is tiny. IIRC the largest balloons can lift about 1 ton. SOFIA's telescope is much larger than that.
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You can't use a single balloon, but we do have multiple balloon technology. Even children can exploit it, although usually only for amusement and not for the purpose of doin' science.
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Let's see, wikipedia says [wikipedia.org] Sofia first light was in 2010, and the contract was awarded in 1996. That's weird, that's the same year the Next Generation Space Telescope program (resulting in JWST) kicked off.
So, wow, Sofia was in development from 1996 until full-scale operations commenced in 2014, 18
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I think most capital still sees space development beyond satellites as pie in the sky stuff, but recently there's been enough private interest to buck the reliable and porcine methods forced on NASA. It would have been better to have NASA do this stuff by more efficient methods than to wait for billionaires to decide it was a good idea, because we'd have done it sooner, but... congress.
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SOFIA was intended as a stopgap until JWST was launched.
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yeah, SOFIA was years late as they'd underestimated the amount of development required.
Re:Airship? (Score:4, Interesting)
They can get *significantly* higher than a 747 type plane ever will. Its certainly not unheard of for hydrogen balloons to beat the Karman Line, but a Helium balloon will handily get you to around 30 km. Over twice the height Sofia operated at, and with a lot lower fuel costs. Although god knows Helium aint as abundant as it once was.
And yeah, the JWST is obviously the superior telescope, but theres only so many hours in a day to point that thing, so alternatives are needed.
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I'm surprised, but thanks for the information.
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Although god knows Helium aint as abundant as it once was.
Helium is produced as a by-product of conventional natural gas.
But fracking now dominates NG production, and many helium-rich conventional wells have been capped because they aren't profitable.
So helium is in short supply, not because we are "running out," but the opposite: It is being left in the ground.
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hydrogen balloons to beat the Karman Line, but a Helium balloon will handily get you to around 30 km.
Why so? Hydrogen lifts 93% of the displaced air mass, vs 87% for helium. Not much difference at low altitude.
Does the balloon material use up all the mass budget at 30km?
Although god knows Helium ain't as abundant as it once was.
It has been around 24% for quite some time now.
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You'd have to ask the physicists for that. But the nut of it is that it'll rise until its at equilibrium with air pressure and after that height the atmosphere is *lighter* than the helium so theres no lift. Why that line is around 30 km up, whilst Hydrogen gets you pretty much all the way to space, I do not know. I guess its not a linear distribution of pressures going up.
And sure, its 24% for quite some time, but thats partially because we are rationing the shit out of it. (There was a glut a while back w
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And sure, its 24% for quite some time, but thats partially because we are rationing the shit out of it.
Woosh! I meant 24% of the universe for 14 billion years :-) The other 76% is hydrogen, with traces of other elements.
airship should work if it's unstaffed (Score:3)
That could work. It would probably have to stay up there, though. Not go up and down like the plane. Which means no crew. Weather balloons routinely go much higher.
There is a certain altitude at which an airship's bouyancy equals its weight. To fly at any other altitude, it has to use its engines to force the airship up or down. This is why airships normally fly at very low altitudes - so they don't have to use a lot of power to force themselves down landing, or to keep up at cruising altitude.
* Very low me
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That could work. It would probably have to stay up there, though.
Right, I'm picturing it remaining aloft "permanently" (as much as anything can do that.)
Weather balloons routinely go much higher.
Exactly. I looked up and read some abstracts before I suggested it :D
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The largest high-altitude balloon in the world (NASA's 'Big 60') has a volume of 1 million m3, and carries 800 kg to an altitude of 48 km. SOFIA weighs on the order of 20 tons. Using balloons that large routinely would quickly deplete world helium reserves.
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Sounds like a job for an airship. Maybe we should do some more work on high-altitude airships [nasa.gov].
It was an infrared telescope on the plane, so it (now) looks like a job for the James Webb Space Telescope ...
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Re: Yet Another Reason For A Real Space Station (Score:2)
And if the nukes start flying (Putin is getting antsy on the button again) then all of this "defense spending" would ultimately be for nought, except delaying the inevitable.
And people like Putin don't appear out of thin air. There is rotteness from the very botton of society to the very top that caused Putin (and T____ in the US) to get to where they are (or were) in the first place.
Yes, there is collective guilt here, and I am not sorry in the least for pointing it out.
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We need orbital indusries and an orbital habitats
No, we don't. The lesson learned from the ISS is that nobody has much use for a space station.
When is NASA going to start construction?
Why should NASA build it?
If an industrial space station is such a great idea, capitalists can build it with their own money.
RIP (Score:2)
:-(
At least it had a good run.