Here’s an “Offset” for You

I’ll drop this here to offset the not-so-cheerful video by David Attenborough that I just posted [stderr] [And that, in a nutshell, illustrates how “offsets” are bogus: you still get to pollute or do the bad thing, you just make someone somewhere else suffer for it.]

A group of NASA engineers used the JWST as a really spiffy selfie-stick:

So, apparently it’s mostly down to slowly/fully tensioning the heat shield, and then aligning the mirrors, which have to cool fully down before they can be accurately aligned. I know it’s “just a matter of building a very small gear-drive transmission” but the alignment of the mirrors has to be on the order of billionths of an inch accurate, and each one has little wee bitty widgets to do it. I guess that’s one hell of a way to avoid having problems like the Hubble did – it’s an adjustable mirror system that is shaped to precision after it’s deployed.

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I’ve decided I will only refer to it as the “JWST” because I don’t think it reflects the ingloriousness of its namesake.

I used to work with a guy who worked for the NRO back in the day, and one time we were talking about the Hubble and he said “it’s an ‘Arkansas cousin’ of a KH-11/KENNEN” um. I still don’t know how much of that is true, but if you look at pictures of the Hubble and the spy satellite, it is kind of interesting.




Just for fun, I switched the images around to see if you knew which was which. Another spook I once talked to made a rather bold assertion that the Hubble’s mirror flaw was because Perkin/Elmer used a mirror design that was also from a spy satellite and was designed to look through atmosphere not space. I don’t believe that one, it sounds just a bit too spooky for me. Spooks lie a lot, that’s one problem with talking to spooks.

By the way, if a spook ever says, “I could tell you but then I’d have to kill you” the correct response is, “well, tell me then! Suicide by spook sounds awesome!” There are no secrets that come with a kill order attached. Not even the ones ‘Q’ is making up.


  1. Jörg says

    There are no secrets that come with a kill order attached. Not even the ones ‘Q’ is making up.

    How would you know? Everybody who got told such a secret is dead! ;-)

  2. crivitz says

    You did manage to fool me with the Kennen/Hubble switcheroo, but I did kind of wonder why the supposed Kennen was pointed out to space rather than to the earth.

  3. Who Cares says

    I’d say the bit about the mirror being shaped to better look through atmosphere is bovine excrement.
    To many variables to account for to use a static mirror. It is why telescopes with adaptive mirrors project a guide star so that they can change the form of the mirror to match how the atmosphere is messing up the light received that very second.

  4. Pierce R. Butler says

    There are no secrets that come with a kill order attached.

    Maybe not in the National Security agencies, but I’ve heard that in utterly convincing ways from Apple™ employees.

  5. dorfl says

    I can add one more “cool but unverifiable” story that I heard passed around during an astronomy workshop: There’s been a lot of worry since the JWST sunshield is basically the first of its kind. It’s been tested in the lab, but it could turn out that there’s some unforeseen issue that causes it not to work in the field. Supposedly, several of the engineers behind it previously worked on spy satellites, and if you ask them about it – they won’t say outright that there are spy satellites using that kind of sunshield already, but they’ll sort of act like this is already well-tested technology.

  6. StevoR says

    @7. dorfl : Tahnks that’s fascinating and strangely reassuring.

    I wonder if such (hypothetical – or not?) satellites could oen day be repurposed for scientific use?

    Can’t recall whether I shared here already or not but folks can follow the JWST’s deployment progress here :

    Among other places too in hope that helps anyone.

  7. says


    Repurposing is probably not possible. It would require refueling AND it would require that the US intelligence apparatus to decide that they don’t want the capabilities of the Satellite anymore.

    Trust me: it’s spendy to get things into space. Even an old spy satellite with a resolution of a meter per pixel or so would give backup coverage so that you could at least see tanks/big olive trucks moving. Since you might have to wait a number of hours to look at something with your state-of-the-art satellite, it’s at least theoretically possible that a nation who knows the orbits of your satellites (like, say, Russia) might want to time a military advance-to-incursion on one of your allies (say, Ukraine) for just after a satellite passed over, giving you & your ally minimal warning time. The old satellite would have trouble distinguishing lots of things, but even meter-per-pixel resolution (and these have better than that) could spot a fleet of ships, a convoy of trucks, or a column of tanks.

    So the US would never give them up to another use, once they paid to put them in space and so long as they had any operational capabilities. But of course once the fuel runs out & you can’t orient your scope in the direction you want to view, you don’t leave it up there for a Russian space shuttle to go inspect it while it has no fuel to get away. You de-orbit it, without a heat shield, targeting a deep, deep section of the ocean. Then even if they could find the wreckage, they probably couldn’t retrieve it. And even if they retrieved it, they couldn’t make much out of the melted, scorched, and then corroded remains.

    Short version: the US intelligence apparatus is too paranoid to do what is necessary to allow those spy satellites to be used for serious scientific research.

    On the other hand…
    I read a story in Scientific American a few decades back about using a long-wavelength telescopic satellite to peer at the Nile delta and find solid, rocky remains of ancient egyptian buildings and art. IIRC they mapped a sewer system that had once been used by a city that was later destabilized by earthquakes and rolling silt. Turns out that the rock walls of the system they were examining were similar to the thickness of the concrete used to build USSR missile silos, and the space from one side of the silo to the other was larger than the space between one wall of the sewer and its opposite. Apparently it was a situation where we **wanted** the USSR to know our capabilities because we were telling them that they can’t hide their missile silos from us without saying, “You can’t hide your missile silos from us”.

    So they do sometimes do a bit of research by accident.

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