
The James Webb Telescope, the largest science project in US government history - Tomte
http://arstechnica.com/science/2016/03/meet-the-largest-science-project-in-us-government-history-the-james-webb-telescope/
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nickhalfasleep
This article also fails to mention that this beautiful, shiny telescope will
assemble itself with atomic precision after having the snot shook out of it at
several G's by the launch vehicle to get it there.

In exoplanet identification and characterization is where I bet the Webb will
make it's place in history for the researchers. IR is a great frequency to
show liquid / gaseous water in an atmosphere of an earth like planet, and if
all goes well, this telescope will be able to detect that.

That is something a spy satellite doesn't have to do, have decent resolution
for items next to suns many orders of magnitude larger and brigher than they
are.

~~~
rootbear
All of NASA will be on sedatives until this thing unfolds itself successfully.
It's even more scary than the Curiosity sky crane landing system.

~~~
topspin
JWST seems like too much for NASA given the record. Galileo's high-gain
antenna deployment failure, Hubble optics flaws, numerous near fatal problems
with GP-B, MCO burning up... all of these and more speak to NASA's track
record with complex space observatories.

At L2 JWST will be beyond the reach of astronauts at the time it's launched,
so all this stuff; cryocoolers, folded sunshield, folded reflector, etc. have
to `just work' with no opportunity for repairs. It just doesn't seem likely.

I desperately want it to work, but if it were up to me I'd trade it in for a
large but mechanically simple optical interferometer, launched by spacex or
whomever, bolted together at the IIS and operated from a serviceable orbit.
That would be a lot closer to what one should expect of NASA.

~~~
rootbear
I don't think it's possible to do the science they want JWST to do unless you
get out to L2 or beyond. They are basically measuring heat, and Earth puts out
a lot of that. And they want to be in an orbit that doesn't pass into shadow,
for reasons of solar power. I understand, and somewhat share, your concerns,
but JWST is designed the way it is because that's how it has to be done to
accomplish its goals.

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mturmon
The cryocooler for the infrared imager has proven to be the toughest design
issue with JWST, at least so far, and AFAIK it's still on the critical path
for the mission. ([http://spacenews.com/northrop-grumman-at-last-set-to-ship-
tr...](http://spacenews.com/northrop-grumman-at-last-set-to-ship-troubled-
jwst-cryocooler/))

I was surprised the cryocooler was not mentioned in the article. The sunshade
is there, but that's not nearly as big an engineering challenge.

~~~
leephillips
Fair point.

But try to juggle context, tutorial scientific background, factual overview,
news, human interest, and inspiration, and you'll be amazed how fast your
allotted 3,000 words gets used up.

~~~
mturmon
Sure, I get it. You covered a lot of ground.

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tfm
"Putting an astronomical telescope in space was a natural solution, and it
followed directly—and, according to some, very directly—from the spy satellite
program."

Can anyone expand upon this? I know the NRO has recently donated some of its
old gear to NASA, but is there much cross-pollination between the space-
operating agencies?

~~~
drzaiusapelord
I also have trouble with this claim. Its been documented several times that
problems NASA stuggles with have sometimes been solved by the DoD, but due to
classification cannot be shared with NASA. No, this isn't some evil
conspiracy, but NASA is open-ish and the contractors that do their work don't
do so under classification, so anything given to NASA would quickly fall into
the hands of America's enemies.

That said, I think this is true in a very general sense for more commodity
space tech. Lets say, lens grinding on this level has been done for DoD
projects, but because that's probably not classified (at least past a certain
level), its easy for NASA's contractors to just re-use that lens grinding
method than re-engineering a new one. Because the spy satellite programs are
classified, we really can't know how much of it goes back into NASA programs,
but I imagine something might.

~~~
mturmon
Let's suppose you were an expert in optical design for space systems --
lenses, mirrors, coolers, detectors, electronics, thermal design -- and worked
at NASA on a space telescope.

When that space telescope (say it was Hubble or Spitzer) was launched, you
would be looking for another project. That's a small world. Maybe you would
talk to a friend who works for intelligence agencies and find out what they
are looking for.

And the reverse happens too. If you've explored the design space for an
intelligence agency, you would be well-positioned to re-use that knowledge for
a space telescope. You mention the classification barrier, but the basic
physics drivers will be more apparent the second time around.

Case in point: Larry James
([http://www.jpl.nasa.gov/about/bio_james.php](http://www.jpl.nasa.gov/about/bio_james.php)),
who is the Deputy Director for JPL, but who used to be Air Force Deputy Chief
of Staff for Intelligence, Surveillance and Reconnaissance at the Pentagon,
and who before _that_ was a Shuttle payload specialist. He's a technical
executive, but there are pure technical examples as well.

OK, and a second example, of a segmented mirror demonstrator:
[http://www.nps.edu/About/News/NPS-New-Home-for-Giant-
Segment...](http://www.nps.edu/About/News/NPS-New-Home-for-Giant-Segmented-
Mirror-Space-Telescope-.html) ("NASA’s James Webb Space Telescope, named for
the former NASA administrator and scheduled for launch in 2014 [ _erp!_ ],
will deploy the next generation of SMT technology on a mission to image light
from the earliest galaxies in the universe.")

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madaxe_again
Nice article, but the diagram halfway down that shows the EM spectrum.... I'm
scratching my head over why "Audio" is apparently now electromagnetism.

~~~
aylons
Audio signals may - and usually are - represented by EM waves. Do not confuse
"audio signals" with "acoustic signals". The diagram is not only easy to
understand, but also technically correct.

~~~
noselasd
The same image appears on
[https://simple.wikipedia.org/wiki/Electromagnetic_spectrum](https://simple.wikipedia.org/wiki/Electromagnetic_spectrum)
with the text:

"NOTE: The AUDIO entry in this graphic is there for comparison only. Sound
waves and light are two different things entirely."

Imo still somewhat confusing. I've never heard anyone refer to something on
the EM spectrum as audio before.

~~~
aylons
You went to the simple image wikipedia just to find a citation that agrees
with you, while the english Wikipedia has a whole artcicle describing it in
quite an opposite way:
[https://en.wikipedia.org/wiki/Audio_signal](https://en.wikipedia.org/wiki/Audio_signal)

If it is confusing, is because you do not understand what a "signal" means. A
signal is not the phenomenon itself, it is a representation of it.

An audio signal is a signal that represents sound, but it is not sound itself.
If it were, you would not need to call it a signal, it would be simply
"sound". In a slightly different use of adjective, an acoustic signal is a
signal (that may or not be audio, eg, ultrassound) that is carried by sound
waves.

Actually, it only gets confusing if you try to be pedantic, as GP did.
Everyone knows what an audio signal in a EM chart.

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rootbear
I work at NASA Goddard where JWST is being assembled and by coincidence I went
over to look at it today and take a picture. Looking at it from the
observation area, I am once again reminded how enormous this thing is! Getting
a look at something like this can help restore one's perspective, when one is
having a bad day, and be reminded of the amazing things that are done here. I
am not attached to JWST but the group I'm currently in did some work on the
detectors years ago. NASA has a lot riding on this instrument, to be sure. I
look forward to the amazing things it will show us when it's finally on
station doing science.

~~~
grinich
Can you share that photo?

And also who would I ask about getting a tour? ;)

~~~
rootbear
I'm not sure if this works, but let's try:

[https://www.facebook.com/photo.php?fbid=10207140470964842&se...](https://www.facebook.com/photo.php?fbid=10207140470964842&set=a.1206665601489.32464.1074121529)

~~~
leephillips
Worked for me! Thanks!

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niels_olson
So there will be one pointed out at the stars, but I wonder how many NRO will
point back at us?

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sanxiyn
Isn't the largest science project in US the Superconducting Super Collider?
Yes, it was cancelled, but JWST was almost cancelled as well.

~~~
melling
I'm not sure what you are trying to reason. X was cancelled but Y was almost
cancelled. That makes no sense.

According to Wikipedia, $2.2 billion was spent on the SSC before it was
cancelled in 1993.

[https://en.m.wikipedia.org/wiki/Superconducting_Super_Collid...](https://en.m.wikipedia.org/wiki/Superconducting_Super_Collider)

It's unfortunate that it was never completed, it was going to be bigger than
the LHC. Everything we are learning now could have been learned a generation
ago.

~~~
kjs3
Claiming we'd have learned everything the LHC taught us a generation ago also
doesn't make much sense, considering the vast improvements in sensor
technology and data handling that happened between the last generation and
this. It's just as likely we'd have seen little or nothing because our "eyes"
weren't sensitive enough or we couldn't find the needle in the data haystack.

~~~
jgalt212
Perhaps, but in high energy physics, size matters. Or at least size matters
more than most other dimensions.

~~~
TheOtherHobbes
I'd suggest computing matters more.

The SSCO would have been crippled by the sensor and computing technology
available at the time. It would have been able to make very small things go
"boink" a lot, but it would have had problems capturing a fat enough stream of
data to record the results.

LHC wins because signals are statistical, and the more data you have the more
reliably you can say "Uh huh - that's a real signal and not just one of those
random things that happens sometimes."

See also the current debate about whether or not something real is going
"boink" at 750GeV.

