The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory • Hacker News Board

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#41

Post by welterde » Fri, Jul 04, 2014, 11:54 AM UTC

privong wrote: post #11

goodcanadian wrote: post #9

Earlier quoted context omitted.

Indeed, there are a couple of key things to note: 1) JWST has not been launched, yet. 2) SOFIA's wavelength coverage is different that JWST's or anything else that is in the pipeline. So, really, they are complimentary observatories.

> 2) SOFIA's wavelength coverage is different that JWST's or anything else that is in the pipeline. Depending on what you mean by "pipeline", that isn't quite true. Work is being done on several far-inrared missions, such as SPICA[0]. I'd consider SPICA to be in "in the pipeline" and it will cover much (if not all) of the far-infrared that SOFIA does. So I wouldn't call JWST and SOFIA complementary; rather, SOFIA is…

I wonder how much more expensive Herschel would have been, if ESA had gone with an closed-cycle cooler instead of using a limited liquid Helium supply directly.

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#42

Post by chenelson » Fri, Jul 04, 2014, 7:08 PM UTC

tekacs wrote: post #39

chenelson wrote: post #33

Earlier quoted context omitted.

And, I guess, Bill Maher is a right-wing nutty? He believes Mars and Moon missions would be a great waste of money. The Bible isn't holding us back....it's our lack of imagination and lazy jokes and the conflation of capital and fiat currency.

... or both you and the GP are partially right and _both_ are holding us back. :/

If we took religion away from history, would we have science?

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#43

Post by qwerty_asdf » Fri, Jul 04, 2014, 7:27 PM UTC

  The telescope on board is 10 times as sensitive 
  and has triple the resolution of NASA’s Kuiper 
  Airborne Observatory, originally launched in 
  1975 on a converted C-141 military cargo plane, 
  and decommissioned in 1995. That telescope was 
  the first to spot the rings around Uranus.

"...the rings around Uranus."

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#44

Post by privong » Fri, Jul 04, 2014, 9:15 PM UTC

welterde wrote: post #41

privong wrote: post #11

Earlier quoted context omitted.

> 2) SOFIA's wavelength coverage is different that JWST's or anything else that is in the pipeline. Depending on what you mean by "pipeline", that isn't quite true. Work is being done on several far-inrared missions, such as SPICA[0]. I'd consider SPICA to be in "in the pipeline" and it will cover much (if not all) of the far-infrared that SOFIA does. So I wouldn't call JWST and SOFIA complementary; rather, SOFIA is…

I wonder how much more expensive Herschel would have been, if ESA had gone with an closed-cycle cooler instead of using a limited liquid Helium supply directly.

I'm not sure closed-cycle coolers can get as cold as evaporation of liquid helium? Herschel was cooled to ~1.7 K [0] while MIRI will only be cooled to 7K [1]. Also, with regard to reliability, evaporation of liquid helium is a pretty foolproof design, while closed-cycle systems can potentially break and end a mission early.

[0] https://en.wikipedia.org/wiki/Herschel_Space_Observatory#Ins...

[1] http://jwst.nasa.gov/miri.html

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#45

Post by rbanffy » Sat, Jul 05, 2014, 1:13 PM UTC

chenelson wrote: post #33

rbanffy wrote: post #20

Earlier quoted context omitted.

One could always ask for support saying a given experiment could prove the, say, biblical flood or somethimg equally silly. If someone believes that all animals on Earth descend from the living cargo of a wooden ship, it should be possible to convince them of anything . Hacking a right-wing nutty congresscritter is an intriguing concept.

And, I guess, Bill Maher is a right-wing nutty? He believes Mars and Moon missions would be a great waste of money. The Bible isn't holding us back....it's our lack of imagination and lazy jokes and the conflation of capital and fiat currency.

> He believes Mars and Moon missions would be a great waste of money.

If they fail to inspire people to continue exploring, yes. I would prefer Moon missions because they'd be cheaper and, as far as inspiration goes, they'd achieve the same results. How many brilliant people have chosen to dedicate their talents to building web technologies because space is no longer cool?

Also, being able to build self sustaining off world colonies may prove handy if we end up unable to stop climate change...

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#46

Post by chenelson » Tue, Jul 08, 2014, 1:57 AM UTC

rbanffy wrote: post #45

chenelson wrote: post #33

Earlier quoted context omitted.

And, I guess, Bill Maher is a right-wing nutty? He believes Mars and Moon missions would be a great waste of money. The Bible isn't holding us back....it's our lack of imagination and lazy jokes and the conflation of capital and fiat currency.

> He believes Mars and Moon missions would be a great waste of money. If they fail to inspire people to continue exploring, yes. I would prefer Moon missions because they'd be cheaper and, as far as inspiration goes, they'd achieve the same results. How many brilliant people have chosen to dedicate their talents to building web technologies because space is no longer cool? Also, being able to build self sustaining of…

I think if something is inspirational, it must be realizable; thus, unless we're talking about mining the moon and requiring human's for labor, we're going to miss the point.

Climate change on Earth is a constant, and if time is x, human existince is a speed bump.

Re: The Jet With a 17-Ton Telescope That NASA Uses as a Flying Observatory

#47

Post by welterde » Sun, Jul 13, 2014, 2:57 AM UTC

privong wrote: post #44

welterde wrote: post #41

Earlier quoted context omitted.

I wonder how much more expensive Herschel would have been, if ESA had gone with an closed-cycle cooler instead of using a limited liquid Helium supply directly.

I'm not sure closed-cycle coolers can get as cold as evaporation of liquid helium? Herschel was cooled to ~1.7 K [0] while MIRI will only be cooled to 7K [1]. Also, with regard to reliability, evaporation of liquid helium is a pretty foolproof design, while closed-cycle systems can potentially break and end a mission early. [0] https://en.wikipedia.org/wiki/Herschel_Space_Observatory#Ins... [1] http://jwst.nasa.gov/m…

Are the individual instruments cooled to that temperature though? Because if they are not, then the difference doesn't matter.

Had a look at the SPIRE manual [0][1] and it seems that Herschel does include an Helium cooler to cool SPIRE and PACS to 300mK.

On the other hand a closed-cycle system can also extend the mission, since you won't run out of cooling at a fixed point in time.

[0] http://herschel.esac.esa.int/Docs/SPIRE/html/spire_handbook.... [1] http://herschel.esac.esa.int/Docs/Herschel/html/ch02.html