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Christmas in June
June 4, 2012 12:55 PM   Subscribe

The United States Department of Defense has generously "decided to give NASA two telescopes as big as, and even more powerful than, the Hubble Space Telescope." They apparently had some antiquated spy satellite hardware sitting around unused and unwanted. NASA still needs to find money to outfit them with recording instruments and pay a team to manage them, which may take 8 years
posted by crayz (69 comments total) 24 users marked this as a favorite

 
Also, from HN discussion:
I worked on the Hubble (my dad was systems manager for Perkin-Elmer's bid), on the ball bearings. They are literally the ones that were rejected from the spy sats.

The spy sats bought a bunch of ball bearings (these might be a foot in diameter and are speced to be extremely low noise at low turn rates). They tested them all (using a phono needle resting on the outside of the bearing while it was slowly turned). The ones that made the least noise went in the sat while the others were sealed in a plastic bag and put on a shelf in the clean room.

I was told that when Hubble came along, the US no longer had the capability to make those (I'm not sure if that was true). In any event the ones that went in Hubble were the least noisy of the ones that had sat on the shelf.
posted by crayz at 12:56 PM on June 4, 2012 [18 favorites]


At last, we can read newspapers on the Moon!
posted by Capt. Renault at 1:00 PM on June 4, 2012 [2 favorites]


For a moment I read NASA as NSA, which would better fit with my expectations of defense spending.
posted by slogger at 1:01 PM on June 4, 2012 [1 favorite]


In space no one can hear your ball bearings.
posted by Trurl at 1:02 PM on June 4, 2012 [12 favorites]


I know all about America's priorities, but it's still kind of a shock to hear it spelled out like that.
posted by Stagger Lee at 1:03 PM on June 4, 2012 [31 favorites]


Ditto.
posted by victory_laser at 1:04 PM on June 4, 2012


Peace dividend!!!!!
posted by wenestvedt at 1:08 PM on June 4, 2012 [3 favorites]


I'm pretty sure this is a carefully-designed experiment intended to simultaneously improve and destroy morale at NASA.
posted by Tomorrowful at 1:10 PM on June 4, 2012 [12 favorites]


The fact that both the Hubble and the KH-11 imaging satellites fit into the same space is widely believed to be not that much of a coincidence.

The long part, here, will be getting the instruments. Just the first call for proposals is going to be crazy fun. First, NASA's going to need to unpack the documentation and figure out exactly what the instrument fit specifications are -- how large can they be, how much power can they draw, etc.

Installing them, once they make them, won't take long, and launching them is easy enough -- Delta IV Heavy.

But, wow -- NASA was just handled two HSTs, without the primary mirror flaw, and with steerable secondaries. That's huge, given that HST is coming to the end of its useful life.

Indeed, I'd only launch one of them -- you won't get servicing missions like HST had, so build the best instruments you can and orbit, when they fail or you have to bring it down, then build better instruments and fly them in the other copy.

Then, of course, find out who built them and see what a few more copies cost. After all, the design is the hard part. We know they built many of these....
posted by eriko at 1:13 PM on June 4, 2012 [5 favorites]


Honey, those idiots on Alpha Centauri haven't taken in their garbage cans again!
posted by arcticseal at 1:13 PM on June 4, 2012 [2 favorites]


"The good news is that we're giving you a network of high powered observation satellites. The bad news is that you'll be maintaining them, and they'll be pointed at the Earth."
posted by Stagger Lee at 1:17 PM on June 4, 2012 [2 favorites]


eriko: " But, wow -- NASA was just handled two HSTs, without the primary mirror flaw, and with steerable secondaries. That's huge, given that HST is coming to the end of its useful life."

Yes, exactly. And Hubble cost what, $2.5bn? A fantastic windfall for NASA!
posted by zarq at 1:18 PM on June 4, 2012 [1 favorite]


What, if anything, does this mean for the James Webb telescope? Hopefully this isn't some sort of back-door ploy for NASA's legislative enemies to use to kill the Webb telescope.
posted by Thorzdad at 1:20 PM on June 4, 2012 [1 favorite]


That's huge, given that HST is coming to the end of its useful life.

All Hollywood exaggeration aside, if the 'better than Hubble' telescopes are entirely worthless to the DoD, you'd have to assume that what they are using is at least a generation better, surely. They're not going to give away their 'close second' stuff in case they need it, so presumably what is up there and running (or about to be) kicks Hubble's arse into a cocked hat.

It quotes Hubble itself as capable of seeing a dime on the washington monument. And that is the old and crappy telescope from space tech... Scary.
posted by Brockles at 1:22 PM on June 4, 2012 [4 favorites]


Wow, I am so conflicted by this news and what it says about our priorities as a nation.
posted by odinsdream at 1:22 PM on June 4, 2012 [8 favorites]


Hey, guys! We were going to tape a bottle of Madeira to the side of one of our drones, but it looks like it might throw off the balance or something? Something about aerodynamics? Anyway, if you want to drink it while you do your space photo shit, you can have it I guess.

We actually put it in the dumpster behind the cafeteria a second ago, but then Dan was like, "Oh wait maybe the poindexters might want it?" so it's only got a little bit of cole slaw on it.
posted by Greg Nog at 1:23 PM on June 4, 2012 [35 favorites]


It quotes Hubble itself as capable of seeing a dime on the washington monument.

I was told by a Chinese student once that members of the Chinese military aren't allowed to look at any sensitive information/maps/etc outdoors, because they assume it's being read
posted by crayz at 1:24 PM on June 4, 2012 [13 favorites]




I was told by a Chinese student once that members of the Chinese military aren't allowed to look at any sensitive information/maps/etc outdoors, because they assume it's being read
posted by crayz at 1:24 PM on June 4 [+] [!]


Meanwhile, fire departments everywhere struggle to get handheld radios that work reliably.
posted by Stagger Lee at 1:28 PM on June 4, 2012 [21 favorites]


Some of Hubble's instruments would be damaged by trying to observe the Earth; it's too bright. The same will probably be true of these two scopes as NASA is likely to instrument them.

The James Webb scope is expected to teach us a lot, but it's an infrared telescope. It will be great to have such a large platform in that previously blocked band, but I'd like us to still have a space telescope capable of visible imaging. In that sense Webb really won't be a replacement for Hubble, but these two scopes could be.
posted by localroger at 1:33 PM on June 4, 2012 [2 favorites]


Bear in mind that just building the telescope itself is no-where near the full cost of a project like Hubble (or one of the KeyHole satellites for that matter). You have to pay to build the instruments to go in the thing, for the crew of people needed to keep the mission running and processing the data, the launch costs, the cost of any mid-mission updates or upgrades etc etc. None of these things are cheap.

What, if anything, does this mean for the James Webb telescope?

Nothing. The mirror on the Webb telescope is huge compared to these: 6.5m in diameter. Plus, the JWT is optimised for infrared observation, which these telescopes almost certainly aren't.
posted by pharm at 1:34 PM on June 4, 2012


Someone please tell me that this isn't the government equivalent of cleaning out my garage and giving most of the stuff to that weird couple who lives down the street instead of hauling it all the way to the dumpster behind the grocery store then?
posted by Blue_Villain at 1:38 PM on June 4, 2012 [2 favorites]


Someone at the Washington Post has a real sense of humor about space funding
The surprise announcement Monday is a reminder that NASA isn’t the only space enterprise in the government — and isn’t even the best funded.
Gosh, really? NASA isn't as well funded as the military and spy agencies? I'm pretty sure my surprised face is visible in KH-11.
posted by Nelson at 1:39 PM on June 4, 2012 [8 favorites]


Why would the Department of Defense be looking at the Deep Field View?

Is the Truth really out there?!
posted by DigDoug at 1:42 PM on June 4, 2012


From what I've heard so far (including discussions with someone who had known this announcement is coming), these are very far from complete satellites - so what's needed is not just the instrumentation, but also the superstructure, solar panels, computers, wiring, star trackers, etc. etc. etc. It's not comparable to NASA being given two Hubbles, but rather just the mirror assemblies for them.

This is still a big leg up for getting future space telescopes built. Money will have to come from somewhere to do it, though (currently there's basically no money in the NASA budget for new space telescopes other than JWST over the entire next decade). 2.4 meter mirrors have almost 4 times the collecting area (which determines the science capabilities) as the proposed WFIRST project, but even with the mirrors provided for free the bigger satellite will likely cost ~4x as much to build and launch as WFIRST (based on a very rough estimate from a knowledgeable individual).

If you are interested, it might be worth following the comments on this blog post; so far, 25% of them are from a Nobel Prize winner (and another 25% are by a leader of the new efforts who's at the forefront of the field).
posted by janewman at 1:50 PM on June 4, 2012 [4 favorites]


Kickstarter!
posted by tilde at 1:52 PM on June 4, 2012 [18 favorites]


The two new telescopes — which so far don’t even have names, other than Telescope One and Telescope Two

I say call them "Thing 1" and "Thing 2", but Tweedledum and Tweedledee seem somehow more appropriate.
posted by Gungho at 1:55 PM on June 4, 2012 [3 favorites]


Is it time to get rid of the US Defense complex as we know it and, as a society, progress to the future yet?

No? They still need 50% of our tax revenue to protect us from boogeymen? Terror alert status orange? Ok, I'll go back inside.
posted by Salvor Hardin at 2:02 PM on June 4, 2012 [4 favorites]


I was told by a Chinese student once that members of the Chinese military aren't allowed to look at any sensitive information/maps/etc outdoors, because they assume it's being read

What is the (theoretical) best resolution a spy satellite could get? Serious question. Best I've heard of is half a meter, but I've no expertise on this.
posted by IndigoJones at 2:08 PM on June 4, 2012


The telescopes are a little big for NASA right now, but he'll grow into them.
posted by brain_drain at 2:11 PM on June 4, 2012 [1 favorite]


They still need 50% of our tax revenue to protect us from boogeymen?

And yet they can't come up with the scratch to keep our bathrooms clean and the trash cans empty. Seriously, prisoners get better facilities than what I have to put up with at work.
posted by backseatpilot at 2:26 PM on June 4, 2012


A fantastic windfall for NASA!

LALALALALALALALA I COULDN'T QUITE HEAR THAT.

Please don't use 'windfall' and 'NASA' in the same sentence ever in DC around budget time. Or any time. You have no idea what the GOP will do next, even with NASA's already skeletal budget.
posted by Slackermagee at 2:32 PM on June 4, 2012 [2 favorites]


IndigoJones, I think the best resolution you can get with these kinds of telescopes is about 5cm. This is due to diffraction; when any wave passes through an aperture, it spreads out (go to a harbor, and watch the waves coming in from the open ocean, you'll see that as they pass the break-wall, the waves will spread into the protected water even though they "shouldn't" if they propagated in a straight-line.) Since light (and really everything, but lets stick with light right now) is a wave, when it passes through a telescope opening, it diffracts, making a pattern of alternating bright and dark rings on the receiving surface. One way to measure the resolution of a telescope then is to figure out how close in angle two point-like light sources could be before the center bright spot of one sits at the 1st dim ring of the 2nd (and vice versa).

The diffraction goes up with the wavelength lambda (longer waves spread out more), and down with the aperture size D (bigger openings diffract less). Turns out that opening angle to the first diffraction minimum is about 1.22 lambda/D for a circular opening. For a 2.5 meter telescope looking at visible light (say 400 nm wavelength), that means the opening angle is about 10^-7 radians. The telescope is about 500 km up, so that means that two objects that are 500 km * 10^-7 ~ 0.05 m = 5 cm apart are at the edge of resolvability.

This diffraction limit is a fundamental limit, so you really can't do better if your technology is based on "big telescope opening to collect light." Though maybe an actual astronomer (janewman) will come and correct me if there's something I missed. I guess that if you use some sort of interferometer (using widely separated small light collectors, basically increasing your effective aperture without the pain of a giant-ass lens/mirror), you could do a lot better, but then you have the problem of collecting enough light to see your target. I have no idea if this has ever been used by spy sats, but considering it was the first thing I thought of, I'm going to guess "probably."
posted by physicsmatt at 2:33 PM on June 4, 2012 [13 favorites]


There's some fantastic information about the resolution capability of the Hubble and spy satellites, the relationship between spy satellite mirrors and the Hubble primary mirror, and other fascinating facts in ... this Ask Metafilter thread.
posted by kyrademon at 2:35 PM on June 4, 2012 [2 favorites]


It is tempting to think that there's rough symmetry in trying to view something in orbit from the ground vs trying to view something on the ground from orbit.

If so, astronomical seeing is the quality to consider:
The best conditions give a seeing disk diameter of ~0.4 arcseconds and are found at high-altitude observatories on small islands such as Mauna Kea or La Palma.
Wikipedia further says of the 50s/60s Keyhole spy satellites
Initially orbiting at altitudes from 165 to 460 kilometers above the surface of the Earth, the cameras could resolve images on the ground down to 7.5 meters in diameter.
A .4 arcsecond disc at 165km is .32m, and at 460km is .9m.

On the other hand, I'm not convinced of my initial hand-wavey argument about the symmetry of looking up from the bottom of the atmosphere vs looking down from way outside the atmosphere…
posted by jepler at 2:35 PM on June 4, 2012


IndigoJones: What is the (theoretical) best resolution a spy satellite could get? Serious question. Best I've heard of is half a meter, but I've no expertise on this.

How big is your mirror, and how high up is your satellite?

With the Hubble Space Telescope, we have a 2.4 m diameter telescope operating at say 240 nm (near UV), which gives us a resolution of (to within factors of 2) about 240x10^-9/2.4 in radians, x 180/pi to get it in degrees, x 3600 to convert to arcseconds, to get 0.02 arcsec, about 20 milliarcsec. That sounds about right to me. (Only an occasional HST user.)

In contrast, if you're looking up through the atmosphere, your resolution is limited by "seeing" - atmospheric blurring - to about an arcsec. Or much worse at Palomar during forest fire season. You can do better at infrared wavelengths, quite a bit better with adaptive optics, but you get the general idea.

Now, I don't know if looking down through the atmosphere has the same problems as looking up through it, but it seems reasonable to guess that it does. So lets go with 1 arcsec seeing, which is 1/206265 radians.

How high up is the telescope? The KH-11 (Keyhole) satellites report orbits around 300 km - that would give them a seeing-limited resolution of 300km/206265 = 1.5m. Good enough for government work?

If seeing isn't an issue (they have super-duper adaptive optics, say) then we can estimate the theoretical resolution of a 2.4 m mirror working at 500 nm wavelengths in a 300 km orbit:
-> Resolving power = wavelength/diameter = 500x10^-9/2.4 radians = 40.3 milliarcsec.
-> 40.3 mas at 300 km corresponds to (500x10^-9/2.4) x 300x10^3 m = 6.25 cm.
Someone should check my math, but that's almost good enough to read a map, and certainly good enough to read a license plate.

But that requires us to believe that the military can perfectly account for atmospheric blurring. (That's not ridiculously far-fetched - they can use reference targets on the ground and tweak things to get crisp lines.) If you need to do better, you need to orbit closer - that's hard - or fly a bigger mirror, which is no problem as long as you are the military and have a few billion $ lying around in the couch cushions.
posted by RedOrGreen at 2:39 PM on June 4, 2012 [2 favorites]


.... aaaaaand Physicsmatt and Jepler have beaten me to it.

Kyrademon, I hadn't seen that thread before either.

Sigh.
posted by RedOrGreen at 2:42 PM on June 4, 2012


Hey, three answers are better than none which what I often get in the blue. Most interesting, much appreciated, thanks to all!
posted by IndigoJones at 2:44 PM on June 4, 2012


NASA has to outfit them with cameras and instruments. NASA also has to come up with the money to pay the scientists to run them...NASA will need eight years to find enough change in the couches at Cape Canaveral to turn these gifts into something they can use.

Do I sense an awesome Kickstarter project?
posted by never used baby shoes at 2:53 PM on June 4, 2012


I sense an awesome echo.
posted by wierdo at 3:03 PM on June 4, 2012 [2 favorites]


metafilter, now with three times the SCIENCE
posted by physicsmatt at 3:08 PM on June 4, 2012 [1 favorite]


two telescopes as big as

Peripheral vision keeps reading this as "two big ass telescopes."
posted by michaelh at 3:11 PM on June 4, 2012 [1 favorite]


Peace dividend!!!!!

Swords into ball bearings.
posted by Blazecock Pileon at 3:19 PM on June 4, 2012 [1 favorite]


Only used on Sunday's to read Gorbachev's Pravda.
posted by tommasz at 3:19 PM on June 4, 2012


You know when you hear about this poor broke guy winning an expensive car, and you wonder how the hell he's going to pay for insurance and keeping it in repair? I hope that's not the case here.
posted by benito.strauss at 3:20 PM on June 4, 2012 [1 favorite]


Two free telescopes? This sounds like a job for aperture synthesis!
posted by The Tensor at 3:24 PM on June 4, 2012 [2 favorites]


backseatpilot: you should get some active duty guys. I swear that out of my 20 years I must have spent at least 10 cumulative years cleaning things, making other people clean things, writing schedules for who was going to clean things when, inspecting things to see if it needed to be cleaned...

World's largest janitorial service, it often seemed like.
posted by ctmf at 3:31 PM on June 4, 2012


Physicsmatt's calculation looks good to me (it's my understanding that spy satellites probably use the bluest possible visible light, so 400 nm is a good number for the wavelength).

The Tensor: aperture synthesis works great at radio wavelengths, but has only been successfully applied in very limited ways in the optical/infrared. The biggest problem is that you need to understand the relative positions of your telescopes to a fraction of the wavelength of light you're looking at - not too hard when the wavelength is 21 cm, but extremely difficult for a wavelength of 500 nm.
posted by janewman at 3:36 PM on June 4, 2012 [2 favorites]


I'd like to see a checkbox on our 1040's where you can elect to give a dollar amount from your refund to NASA. We have them here in Oregon used to finance all sorts of projects.I'm always throwing $5 here and there. I wouldn't mind giving NASA $50. not hard to imagine 10 million Americans kicking in $50 or more that would be at least $500M a year for NASA in addition to their already "meager" budget of 18 Billion or so...
posted by pdxpogo at 3:43 PM on June 4, 2012 [2 favorites]


Peripheral vision keeps reading this as "two big ass telescopes."

Or one enormous pair of binoculars!
posted by arcticseal at 4:12 PM on June 4, 2012 [2 favorites]


The Sec Dev, the NSA and Joint Cheifs do not want to be sitting in the Sitroom getting grilled by POTUS about the alien armada that just showed up in our sky one day without any warning. Sure the odds are minuscule, but they have a trillion dollar budget, and that is just the declassified parts. So sure they are looking at space, listening for alien phone calls, etc. they've seen the movie, Jeff Goldblum is on standby with a Mac Book Pro waiting for this.
posted by humanfont at 4:22 PM on June 4, 2012 [3 favorites]


(it's my understanding that spy satellites probably use the bluest possible visible light)

I now know how to make my sekrit treasure map invisible to spying satellites!
posted by -harlequin- at 4:26 PM on June 4, 2012


Yeah, but I think we really need gravity wave detection and imaging. Seriously, we don't know diddley, and will remain so unless we put brains and money on the line here. Will it mean fewer advanced scopes with pretty pictures for EM studies? Probably, but I think the returns in knowledge gained, no matter how primitive, will tell us a lot more.

Not a cosmologist
posted by wobh at 4:29 PM on June 4, 2012


What little details exist are in two talks on the National Academies site, specifically the ones by Paul Hertz and Alan Dressler.

Quick outline of the known details, for specialists in the field:

- 2.4m, f/1.2 primary
- Configured for cassegrain f/8, 1.6 arcmin FoV
- The structure has heaters on it, probably meant to operate at 300K.
- Hardware is declassified, but nobody will show pictures of it yet.
- Hardware is currently at Excelis in Rochester.

"Over a year ago, the National Reconnaissance Office (NRO) informed NASA that there was residual spacecraft hardware available for transfer."

"The NRO had determined that this hardware was not suitable for future intelligence missions."
posted by kiltedtaco at 4:55 PM on June 4, 2012


janewman: aperture synthesis works great at radio wavelengths

Would super resolution techniques be more useful, at least for spy satellites?
posted by Z303 at 5:49 PM on June 4, 2012 [1 favorite]


wobh: A lot of astronomers (most definitely including cosmologists!) are interested in gravity wave detection ('imaging' isn't relevant here). However, it is very unclear if current technologies can actually do the job (a satellite to test this, the "LISA Pathfinder", is due to be launched next year). Despite the risks, LISA was the #3 space-based priority from the most Decadal review of what we should do in astrophysics due to the great scientific promise.

WFIRST came out #1 in that review, largely as it would provide substantial advances in both cosmology and the search for extrasolar planets. NASA currently has no money slated for any work on it before ~2018, though - even the top priority doesn't fit in the current budget.
posted by janewman at 5:52 PM on June 4, 2012 [2 favorites]


Meanwhile, fire departments everywhere struggle to get handheld radios that work reliably.

posted by Stagger Lee at 15:28 on June 4 [12 favorites +][!]


My handhelds are . . . ok. These are the best I've used. Handheld radios are more limited by power and antenna height than sophistication of electronics.
posted by the man of twists and turns at 6:05 PM on June 4, 2012


Z303: no idea about super-resolution. I've never encountered it before. The examples given on wikipedia appear to correspond either to:

1) what astronomers call 'drizzling', which can't overcome the diffraction limit; it uses multiple images with larger pixels, offset from each other by a fraction of a pixel, to determine what a higher-resolution image with more pixels would look like
or
2) modeling what's in an image, which can be used to infer a little about what's going on at somewhat smaller scales than the diffraction limit - basically, determining what intrinsic image, blurred out by the diffraction pattern/effects of the telescope + instrument, matches what you actually observe. For instance, if you're looking at images blurred by a 2d Gaussian profile with a sigma of 0.5 arcsec, it's not too hard to distinguish a star (with effectively zero intrinsic size) from a galaxy with a radius of 0.4 arcsec. It'd be very difficult to distinguish stars from tiny (e.g. 0.1 arcsec radius) galaxies in such an image, though; and you can't recover any real details about the structure of even the 0.4 arcsec galaxy on small scales (at best you might get a measure of size and overall shape).
posted by janewman at 6:05 PM on June 4, 2012


Who's gonna argue that this is a reason to maintain high levels of defense spending? After all, think of all the jobs it provides, and just look at the neat technology that NASA gets to use as a result!
posted by 2N2222 at 7:22 PM on June 4, 2012


Second-hand DoD hardware which is much better than what NASA is currently using. Makes me wonder how much science could advance if NASA had the budget to get what the DoD is currently using.
posted by pashdown at 7:30 PM on June 4, 2012 [1 favorite]


My husband, a former astro grad student, made the very good point that in a lot of cases probably the guys in reconnaissance and the guys in telescope optics at NASA went to grad school together. Ultimately there are only so many jobs for a dude or lady who knows how to build state-of-the-art instruments that see stuff from far away, and basically the only places to get trained to build those things are astro departments. So it's not at all surprising that the reconnaissance people would be totally delighted to donate their hand-me-downs to NASA - in many cases these are friends or classmates, almost certainly, and in many cases the people working in reconnaissance instruments got into the field through astro.
posted by town of cats at 8:14 PM on June 4, 2012 [3 favorites]


"It quotes Hubble itself as capable of seeing a dime on the washington monument. And that is the old and crappy telescope from space tech... Scary."

Hubble can't actually do that, for a variety of reasons outlined here. (mostly because it's moving too fast to take clear pictures of the Earth).

I'd like to see a checkbox on our 1040's where you can elect to give a dollar amount from your refund to NASA.

Letting individuals choose how to allocate their tax dollars directly would result in lots of telescopes and national parks, but very few sewers, pothole fixes, and other decidely unsexy projects.
Down that path lies madness.
posted by chrisamiller at 8:26 PM on June 4, 2012 [2 favorites]


6.25 cm. Someone should check my math, but that's almost good enough to read a map, and certainly good enough to read a license plate.

What does 6.25 cm resolution mean here? A single pixel mapping to a 6.25x6.25 square would mean ~10 pixels for a license plate - much better than the sattelite photos on Google Maps, but not enough to be able to read the digits.
posted by Pruitt-Igoe at 8:54 PM on June 4, 2012


Pruitt-Igoe: to an astronomer, resolution generally means the smallest separation two objects can have where you can still tell that there are in fact two distinct peaks in brightness rather than one. That turns out to be very similar to the diffraction limit discussed above. Detectors will generally have at least 2 (generally >2.5) pixels per resolution element (information will be lost if there are fewer).
posted by janewman at 9:33 PM on June 4, 2012


I'd like to see a checkbox on our 1040's where you can elect to give a dollar amount from your refund
Letting individuals choose how to allocate their tax dollars directly would result in lots of telescopes and national parks, but very few sewers, pothole fixes, and other decidely unsexy projects.

Last I checked, I already get to choose how to allocate my refund, what with it being money that the government's giving back to me because I don't actually owe it in taxes. I somehow doubt a "send some to NASA" checkbox would bring about the collapse of Western Civilization.
posted by brennen at 10:26 PM on June 4, 2012 [2 favorites]


Brockles: "It quotes Hubble itself as capable of seeing a dime on the washington monument. And that is the old and crappy telescope from space tech... Scary."

To be fair, that's geometric resolution, not real-world. IRL air turbulence destroys that resolution, unless you use real-time turbulence correction, which requires either a nearby target source (in space, a star) or target reflector (typically a retroreflector cube*).

It's just not as simple turning the Hubble around and suddenly peeking in your bathroom window. Without turbulence correction, telescopes are noise-limited to roughly 1'x1' resolution or so. You can tell if the car has a license plate, but not what it reads.

* I've long wondered about this need vis-a-vis spy satellites. Then it occurred to me that all you have to do is drop a retroreflector somewhere in the vicinity, perhaps from a high-altitude plane (with a biodegradable parachute and short-term radio beacon to determine its landing spot). It could be a mile away - whether in Siberia or Somalia, no one is likely to find it. The key feature of a retroreflector is that its orientation doesn't matter, so it can tumble in landing and still work perfectly.
posted by IAmBroom at 8:14 AM on June 5, 2012


brennen: "
chrisamiller: Letting individuals choose how to allocate their tax dollars directly would result in lots of telescopes and national parks, but very few sewers, pothole fixes, and other decidely unsexy projects.

Last I checked, I already get to choose how to allocate my refund, what with it being money that the government's giving back to me because I don't actually owe it in taxes. I somehow doubt a "send some to NASA" checkbox would bring about the collapse of Western Civilization.
"

Apples and oranges. chrisamiller is talking about tax dollars and you're discussing voluntary contributions.

The proposed solution to chrisamiller's objection is the "5% Solution", proposed by some sci-fi author I can't recall. You get to determine where 5% of your tax dollars go, so war hawks can fatten the DOD and tree huggers can supply extra hugs to the Interior or EPA. Presumably, 5% (homogenized by taxpayer interests) wouldn't be enough to topple the govt, especially after the yearly average results were taken into account before budgeting.
posted by IAmBroom at 8:22 AM on June 5, 2012


chrisamiller is talking about tax dollars and you're discussing voluntary contributions.

Yes, it's apples to oranges. chrisamiller was responding to pdxpogo talking about a voluntary contribution, not about allocating tax dollars. A mechanism which is already in place in various states. (See here, for example. Or there's this at the Federal level.)
posted by brennen at 8:43 AM on June 5, 2012


Refund != Taxes you paid.
posted by odinsdream at 8:44 AM on June 5, 2012 [1 favorite]


Years ago, when I was in elementary school and the HST was being built, a group of us got to tour the Perkin Elmer facility where it was being built. By then, though, the mirror blank had already been ground, and wasn't available for viewing as it was off being silvered. A couple of other similar mirrors, though, were out and viewable. I asked what the other mirrors were for, since the HST would only need one. The tour guide, one of the engineers, stayed silent for a while, then asked us not to ask any more questions about those mirrors. In retrospect, of course, it's apparent these were mirrors for use on spy telescopes, and our guide was probably breaking some regulations just by showing them to us. Beautiful things, you could stand at the other end of the big room they were worked on in, and see yourself magnified perfectly, if you stood in the right spot.
posted by Blackanvil at 10:25 AM on June 5, 2012 [5 favorites]


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