Thread

NASA asked several former SR-71A staffers to help secret restart

327 points · 403 comments · ilamont

walrus01 · 1790727565 · focus · HN ↗
I'd be more astonished if there isn't something superior to the SR71 (likely unmanned) that has been flying around at night from facilities like Groom Lake for years. Look at how long the RQ180 was flying around in semi-public and known about before it became seen in daylight by plane spotters in Greece. And a long time before that there were public relations approved photos of the Lockheed Martin Polecat.
There were a series of extremely public quotations from senior DoD officially recently about how they plan to aggressively retire the Global Hawk program (which is a mostly non stealth aircraft), reading between the lines it's because they have something much better.
edit: for those who haven't seen the RQ180: <a href="https://www.google.com/search?client=firefox-b-d&q=RQ180+greece" rel="nofollow">https://www.google.com/search?client=firefox-b-d&q=RQ180+gre...
edit 2 (apologies for the X link): <a href="https://x.com/MechDesignxyz/status/2041281689838584193" rel="nofollow">https://x.com/MechDesignxyz/status/2041281689838584193
1. hilsdev · 1790727775 · focus · HN ↗
  I suspect everything comparable of late has been orbital, which begs the question what is it they’re worried about with orbital? Satellite warfare is already accelerating if the rumors are true, is it that this is untouchable still? Is there some new camera sensor where eliminating that extra atmospheric diffraction or slowing down (lol) is needed?
  1. walrus01 · 1790727944 · focus · HN ↗
    I am sure that the orbital capabilities are also vastly improved from what the public has ever seen. But I think there's likely a high degree of tactical value in having something that can keep station over a certain active conflict area (as an RQ180 can, maybe flying in a racetrack pattern at altitude, with sensors aimed down).
    If you've ever seen the publicly released videos and audio of an RQ9 operator in communication with ground units watching the activity of a group of men/vehicles on the ground, in live real time, something like that.
    As compared to periodic revisits by LEO orbit satellites that don't maintain persistent live coverage, or the extreme distance and data acquisition problem that aiming sensors in geostationary orbit at a 10x10km target area might pose.
    Demiurge · 1790730404 · focus · HN ↗
    There are satellites in geostationary orbit that have realtime live feed and agile pointing capability. However, besides the SAR, RGB style observations are limited by clouds, and also you can’t switch out the sensors on a whim. Airborne platforms are always more flexible and cheaper for certain missions.
    walrus01 · 1790730520 · focus · HN ↗
    Without leaking anything that's even remotely close to classified, WAMI (wide area multispectral imagery) sensor systems that can mount on even relatively medium sized group 3 UAV are really damn good these days. This is a pretty basic unit compared to the things that aren't publicly known:
    <a href="https://www.logostech.net/products/redkite/" rel="nofollow">https://www.logostech.net/products/redkite/
    <a href="https://www.logostech.net/products/blackkite-i/" rel="nofollow">https://www.logostech.net/products/blackkite-i/
    jauntywundrkind · 1790733633 · focus · HN ↗
    This guy has been working on their own SAR drone for a while, just had another really nice blog post. Definitely looks like it weighs <10 lbs. He post-processes, but I doubt that's that hard to rework. <a href="https://hforsten.com/interferometric-synthetic-aperture-radar-drone.html" rel="nofollow">https://hforsten.com/interferometric-synthetic-aperture-rada...
    walrus01 · 1790734313 · focus · HN ↗
    It looks like a DIY implementation of some of the commercial land surveying SAR payloads that companies will sell you (for $60,000) to fly below a DJI M400 or similar size craft for tasks like monitoring open pit mines, etc. Also not realtime data return over RF data link, it's a download and post-process workflow.
    adastra22 · 1790731526 · focus · HN ↗
    I think you are confused. Spy satellites do not use geostationary orbits.
    walrus01 · 1790731837 · focus · HN ↗
    It's not something I can cite with any public URL to a website that's an authoritative source, but if by 'spy' you include SIGINT satellites in that category, yes they absolutely do... Ever seen a diagram of a Boeing (Hughes) 702 series satellite bus and antenna system built for L/S-bands like frequency ranges similar to those used by Thuraya, Inmarsat and Iridium handhelds?
    It's widely accepted in the commercial two way satellite telecom industry that the NSA has comparable things with big unfolding umbrella-like antennas in geostationary which serve a similar purpose for signals collection.
    ErroneousBosh · 1790753741 · focus · HN ↗
    > It's widely accepted in the commercial two way satellite telecom industry that the NSA has comparable things with big unfolding umbrella-like antennas in geostationary which serve a similar purpose for signals collection.
    How does that even work, do people just accept that their satellites hang around suspiciously close to other geostationary satellites and hoover up the very edge of the beam somehow?
    Because if you're transmitting stuff *to* geosynchronous birds you have to aim pretty accurately.
    walrus01 · 1790754980 · focus · HN ↗
    Handheld S/L-band things like Thuraya, Iridium, Globalstar, Inmarsat phones don't transmit in a very directional way at all. Or things like a Garmin inreach that have an Iridium modem in them. They're omnidirectional enough that the broad requirement for a user is to be outdoors with a good view of the sky.
    If you have a NSA-type geostationary satellite somewhere in approximately a 1/5th arc of azimuth along the equator of the earth that can 'see' an area on the ground, with antenna systems aimed at the area of interest (let's say, Afghanistan), it's not necessary for your NSA satellite to be anywhere close to the actual service provider's satellite.
    Note that Thuraya BGAN-like devices and handheld phones talk to geostationary, Iridium is LEO (but likely some combination of LEO, molniya orbit and geostationary can "sniff" it), Globalstar is similarly LEO in its service provider architecture, and Inmarsat is geostationary.
    Also lots of conjecture out there that sigint platforms exist which are good enough to capture ordinary handheld device cellular traffic or VHF/UHF radio traffic that's not intended by its users or terrestrial operators to go into space at all. This is probably done from a combination of low earth orbit platforms and more complicated orbits or what we would call MEO (maybe about the same height as an o3b satellite?) to achieve longer dwell times over an area of interest.
    ErroneousBosh · 1790756677 · focus · HN ↗
    But then with the difference in distance from LEO stuff like Iridium (RIP - I actually saw the ground flash of an Iridium flare once!) you'd need a truly *massive* antenna to hear that out at geosync.
    walrus01 · 1790761766 · focus · HN ↗
    An Iridium 9555 handheld phone talking to Iridium satellites in LEO with its antenna extended transmits in approximately the same frequency range and about the same tx power as an inmarsat isatphone 2. The former is LEO, the latter talks to geostationary.
    Same concept for an Iridium 9555 or its successor in a dock plugged into the small coaxial cable that goes to the external hockey puck sized antenna. This is all happening between approx. 1400 to 1700 MHz in either system.
    Look up the detailed RF specs for the isatphone 2.
    Both of these only work because the channel size is extremely narrow.
    The antenna on the commercial satellites that do two way S/L-band to handheld stuff (or INMARSAT BGAN size terminals) from geostationary is massive, I've no reason to believe that a high budget billion dollar NSA satellite at MEO or higher altitudes wouldn't have a similarly gargantuan unfolding antenna.
    T-A · 1790763327 · focus · HN ↗
    <a href="https://en.wikipedia.org/wiki/Orion_(satellite)" rel="nofollow">https://en.wikipedia.org/wiki/Orion_(satellite)
    adastra22 · 1790809092 · focus · HN ↗
    The NSA does have comparable things. You can even find amateur photos of them in this day and age. But they are not in GEO.
    LorenPechtel · 1790813889 · focus · HN ↗
    The ground units do not have any sort of narrow beam capability, thus you don't need to be anywhere near the satellite to intercept them. I have a low end satellite device: Garmin InReach (text only, provides tracking and emergency communications in the middle of nowhere.) It has a preferred orientation, not a required orientation.
    Demiurge · 1790734916 · focus · HN ↗
    Why do you think I am confused? Is this a form of internet condenscension, or are you able to diagnose my mental state based a single comment? No, I don't think I'm confused.
    adastra22 · 1790809341 · focus · HN ↗
    Because GEO is about 100x further than LEO, which means the signal is about 10,000x weaker. Also the risk to geo communications from having multiple birds in the same slot is huge and treaty violating. Why put that risk and insane demand when you can still get global coverage from a dozen or so birds in high polar orbits?
    Nobody does what you are saying, because physics, which leads me to believe that you are confused.
    walrus01 · 1790812844 · focus · HN ↗
    If you think the US doesn't have a plethora of DoD things in geostationary orbit you would be extremely, terribly wrong. In addition to well known programs like AEHF, WGS for two way military satcom purposes, a person with an amateur grade telescope can literally spot the satellite that keeps station near an existing commercial Thuraya satellite:
    <a href="https://en.wikipedia.org/wiki/USA-202" rel="nofollow">https://en.wikipedia.org/wiki/USA-202
    <a href="https://space.skyrocket.de/doc_sdat/thuraya-2.htm" rel="nofollow">https://space.skyrocket.de/doc_sdat/thuraya-2.htm
    <a href="https://space.skyrocket.de/doc_sdat/thuraya-4.htm" rel="nofollow">https://space.skyrocket.de/doc_sdat/thuraya-4.htm
    adastra22 · 1790826000 · focus · HN ↗
    Those are geosat communications, not surveillance. Surveillance is not happening in GEO.
    crote · 1790760605 · focus · HN ↗
    The problem is that "can loiter over an area" and "SR71-like" are fundamental contradictions.
    The whole point of the SR71 is to be stupidly fast, to the point of being impossible to catch. It could outfly missiles, and the mission was done and over by the point anyone could scramble a proper defense. Have it fly circles over a target and you're negating its one main unique selling point.
    Want to loiter over a target? Use an RQ9. Want an impossible-to-stop snapshot camera? Use a satellite. So what's left for the SR71? I guess there are some missions where 1) you don't have air superiority, and 2) the target can hide in time from well-known satellite orbits, but 3) the target can't hide with 15-minute warning from a plane - but are those really common enough to justify the massive investment it'll take?
    walrus01 · 1790765109 · focus · HN ↗
    I was replying to a comment from a person who was talking about satellite ISR, referring to 'can loiter over an area' for why the RQ180 or similar exists and is used in certain tactical scenarios instead of satellite, not to justify some absurd reactivation of the SR71. Please read the comment I replied to and what I wrote again.
    The RQ9 is fine to loiter over and watch an area that has little to no air defenses, more stealthy things are needed if there's some form of credible air defense. There's a number of non faked photos of downed rq9 in yemen in the past couple years that were shot down by fairly basic air defense systems the Houthis acquired from Iran.
    mrguyorama · 1790780988 · focus · HN ↗
    >There's a number of non faked photos of downed rq9 in yemen in the past couple years that were shot down by fairly basic air defense systems the Houthis acquired from Iran
    We have confirmed the loss of like 40 reapers in Iran.
    mrguyorama · 1790780945 · focus · HN ↗
    Also the SR71 can barely loiter at all. It has a turning circle at altitude and speed of 80 miles
  2. morkalork · 1790737353 · focus · HN ↗
    Well there's also the X-37B Orbital "Test Vehicle" that performs some long-run missions. Satellite warfare? Observation instrument tests? Who knows!
    somat · 1790927025 · focus · HN ↗
    My theory is satellite retrieval, Not ours, theirs. Play the long game, year two of a three year mission, do a little unannounced orbital dance, somebody's spy satellite has a unexpected failure, while really it is now in the rf shielded environment of the x-37's payload bay. Year three, bring it down for study.
    Yeah, probably way to much science fiction there, way too many things would go wrong, and spy satellites tend to have huge antenna have fun trying to stuff that in a rather small payload bay. However... One of the space shuttle mission profiles was to deorbit a satellite. Officially, the space shuttle never did this. But I think the airforce really liked the idea and wanted to retain the capability.
  3. MadrasTh0rn · 1790743947 · focus · HN ↗
    Orbital is becoming less reliable due to escalating threats
  4. numpad0 · 1790752155 · focus · HN ↗
    Satellites are defenseless and easily shot down, either one by one using ballistic missiles or by creating a sweeping ring of debris, in a full scale WW3 where things like treaties and sanctions don't matter
    wafflemaker · 1790754912 · focus · HN ↗
    Pluss any fuel costs 100x the fuel mass on launch.
    So you're sitting in your orbit and any changes (especially so close to the massive body) are super expensive. Which means sending anything after you must be pretty trivial (once the missile is already in orbit).
    Spaceship just launched 30+ starlink v3 sats on its first orbital flight two days ago. It might as well have been flat disks of missile sats, even multi missile per each disk. Sitting there waiting, getting energy from solar, only having to expand fuel when a strong solar storm temporarily increases atmospheric drag on LEO + some minimal station keeping. A missile type sat with completely different budget for fuel and mass has a big advantage.
    Maneuvering for a rendezvous (intercept), given 5-40 hours time, is very cheap in terms of ∆V (fuel used).
    walrus01 · 1790755348 · focus · HN ↗
    > Maneuvering for a rendezvous (intercept), given 5-40 hours time, is very cheap in terms of ∆V (fuel used).
    Only if you're in approximately the same orbital inclination. Plane change maneuvers once in LEO are very expensive in delta V.
    dotancohen · 1790757806 · focus · HN ↗
    The attacking bird needs to raise apogee to GEO anyway - after that the plane change is relatively cheap. They might not even raise perigee.
    walrus01 · 1790765355 · focus · HN ↗
    I was replying to a comment where the person was talking specifically about LEO. Interfering with things in geostationary orbit is a whole other question.
    dotancohen · 1790769686 · focus · HN ↗
    Even for LEO. Plane changes are expensive - and you've got to then wait potentially many orbits to get a collision. To shorten that timeframe you'd change your apogee or perigee anyway.
    Raising the apogee, then changing the inclination there is relatively cheap - and you can adjust the plane change and apogee to time a collision. Remember - there is no need to recircularize. Just collide. If the goal was to recircularize then I don't know if raising the apogee would be worth it, maybe for extreme cases. But not for a collision.
    LorenPechtel · 1790814076 · focus · HN ↗
    Plane change is extremely expensive--but you only need to match inclination at launch. Put your interceptor at a different elevation, wait until the planes align.
    numpad0 · 1790778593 · focus · HN ↗
    More like, you can just launch couple rings of sand into the polar orbit of Starlink altitude ranges. It'll wipe them all off like a window wiper over few days or so. Or the killer sat could have thrusters to rendezvous with each one, but it'll be more complicated with the size of Starlink constellation.
    gosub100 · 1790769500 · focus · HN ↗
    You forgot lasers
    numpad0 · 1790779053 · focus · HN ↗
    Yeah, China can probably do that too in a WW3 situation. A nuclear PSU wherever low enough latitude with a telescope next to it shooting up anything moving it sees. LEO satellites can't avoid covering everywhere on Earth where latitude is lower than its inclination. It probably has to be articulating and tracking, not like fixed Minecraft beacons, but even that will do its job eventually.
    gosub100 · 1790782366 · focus · HN ↗
    or space based lasers, there's no atmosphere to dampen the pulse
  5. bob1029 · 1790755607 · focus · HN ↗
    There are some mission profiles that simply don't work from orbit. You need too much resolution and frame rate.
    <a href="https://en.wikipedia.org/wiki/ARGUS-IS" rel="nofollow">https://en.wikipedia.org/wiki/ARGUS-IS
    Imagine implementing the above from LEO.
    m4rtink · 1790768876 · focus · HN ↗
    So you have these LEO Internet satellite constellations with thousands of satellites that have a number of satellites above any place on Earth at any given moment...
    bob1029 · 1790779416 · focus · HN ↗
    The optical system required to achieve this is infeasible to deploy at the scale required to compensate for concerns like orbital motion at 15+ fps.
    m4rtink · 1790782642 · focus · HN ↗
    Yeah, that would be the main issue for optical imaging. Still rapid change detection could be doable and of course sigint.

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