Thread

The top secret URSALA, RAQUEL, and FARRAH satellites (2025)

306 points · 162 comments · Bluestein

Almondsetat · 1790809198 · focus · HN ↗
The incredible and futuristic technologies the US managed to deploy decades before the competition reminds me of the story of how the NRO gifted NASA a couple of their old decommissioned satellites in 2012 and they turned out to be basically upgraded Hubble telescopes pointed at earth. The US from the 90s to the 2000s had multiple Hubble-level telescopes just for spying while NASA was fighting for scraps to study the entire cosmos.
1. monocasa · 1790813494 · focus · HN ↗
  Way longer than that. The first KH-11 satellites that Hubble shares its design with were in orbit in the late 1970s.
  <a href="https://en.wikipedia.org/wiki/KH-11_KENNEN" rel="nofollow">https://en.wikipedia.org/wiki/KH-11_KENNEN
  1. palmotea · 1790830542 · focus · HN ↗
    > Way longer than that. The first KH-11 satellites that Hubble shares its design with were in orbit in the late 1970s.
    I'm not sure if it actually "shares its design" with KH-11, but has a more indirect connection, e.g.:
    <a href="https://news.ycombinator.com/item?id=23150092">https://news.ycombinator.com/item?id=23150092:
    > My favorite KH-11/Hubble story is that during the design of the Hubble Space Telescope, NASA originally wanted a 3 meter mirror. However when they began to design and budget the satellite they were quietly told they should reconsider and use a 2.4 meter mirror, as this would be significantly cheaper since they would be able to leverage existed machinery capable of created mirrors of that size and precision. That infrastructure and manufacturing process had already been created a decade earlier for Keyhole.
    monocasa · 1790833328 · focus · HN ↗
    Except that's not the only connection. Which is why a lot of the pictures in the wiki page I posted are actually of Hubble.
    ra · 1790838309 · focus · HN ↗
    I often see Hubble in the twilight, it's one of the few big satellites you can readily see with the naked eye - not quite as bright as the ISS but pretty close.
    Why have i never seen these, is it simply that I wasn't looking for them?
    stanac · 1790840843 · focus · HN ↗
    If I was to repurpose Hubble to be a spy satellite I would paint it black... I know it's not that simple due to sun radiation (including heat), they where probably coated with some mat black material or something to avoid this kind of detection. I'm just guessing since Hubble looks like it's wrapped in aluminum foil.
    monocasa · 1790873524 · focus · HN ↗
    Yeah, and block v also have straight up stealth coatings in addition to not being as bright.
    sandworm101 · 1790851679 · focus · HN ↗
    You assume they are in similar orbits. The spy sats might be higher than Hubble, which itself was very high for a shuttle program.
    verzali · 1790871234 · focus · HN ↗
    I have also wondered about similar questions.
    One is that Hubble's mirror is not expected to burn up on re-entry and may therefore hit the ground.
    How is this managed with similar spy satellites? Presumably the problem is more acute, because not only do you need to avoid killing someone, but you also want to avoid any chance of falling on hostile territory. Are they actively steered into known parts of the ocean? Or does something else happen (one suggestion with Hubble was actually to fire a missile at it just before entry in order to break the mirror in space).
    monocasa · 1790873417 · focus · HN ↗
    Yeah, they're deorbited into a known part of the ocean.
    And just because the mirror won't technically completely burn up in reentry doesn't mean it'd leave anything useful for adversaries.
    walrus01 · 1790905291 · focus · HN ↗
    see the part here about Point Nemo: <a href="https://en.wikipedia.org/wiki/Pole_of_inaccessibility" rel="nofollow">https://en.wikipedia.org/wiki/Pole_of_inaccessibility
    monocasa · 1790873268 · focus · HN ↗
    Both an incredibly different orbit, the fact that the location of NRO satellites aren't nearly as published, as well as the newer ones using simple stealth coatings so they don't shine as bright.
    voidUpdate · 1790849249 · focus · HN ↗
    If the manufacturing for the 2.4 meter mirrors existed a decade earlier, and Hubble used the existing processes, does that mean all the KH-11 satellites also have the spherical aberration problem that Hubble has?
    iririririr · 1790850032 · focus · HN ↗
    or hubble has the aberration because the design optimized for cost on that bandwidth, because nobody would ever need to zoom individual fibers on a newspaper page? remember those where pointed the other way around.
    but that's an awesome rabbit hole you pointed out!
    scrlk · 1790857594 · focus · HN ↗
    The spherical aberration of Hubble's main mirror was caused by a manufacturing defect.
    Perkin-Elmer designed a new null corrector to verify that the mirror was made to spec, but the null corrector was incorrectly assembled (one of the lenses was out by a few mm). They also used the previous null corrector to test, which showed that the mirror was incorrectly ground, but decided that the new null corrector's measurements was correct.
    voidUpdate · 1790858602 · focus · HN ↗
    But wouldn't they have needed to do that for KH satellites too? If they're making new equipment and processes, they'll be saving a lot less money from using KH mirrors
    rtkwe · 1790870968 · focus · HN ↗
    It was a new piece of test/validation equipment used on Hubble first. Reread it, they used the new equipment to test Hubble that had an error during assembly, they also crosschecked against the old machine which showed the mirror was flawed, and incorrectly decided that the newer machine was correct when it passed the Hubble mirror.
    The test equipment is a much smaller part of the cost than developing, building and testing the machines required to actually grind the mirrors to spec in the first place.
    sandworm101 · 1790851836 · focus · HN ↗
    The mirror/sensor package is just the payload. The rest of the bird, from power and communications to navigation and pointing, could have been lifted directly from a spysat program.

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