4 ms·

That's interesting, also a possible insight into what the X-37b mission is. Retrieving payloads, but what payloads?

khuey 4y ago
The X-37B is much smaller than the shuttle (it was originally intended to fit in the shuttle's payload bay). It physically can't retrieve satellites of any significant size.
- kranke155 4y ago
  I'm really curious, do we have any idea whatsoever what the X-37 is being used for?
  - cjbgkagh 4y ago
    A big advantage of space planes is the ability to change orbit very quickly, could be used for reconnoissance or as a weapons delivery vehicle.
    - the_third_wave 4y ago
      Only if they're in low enough orbits to make use of atmospheric drag. Such orbits decay quickly if the vehicle does not have boost capacity. Given the extremely long missions this thing flies - several missions over 700 days - it seems unlikely for it to make use of atmospheric drag. It might do so when in a highly elliptical orbit but even then it needs to perform a burn at apogee to keep it from re-entering before long.
      - cjbgkagh 4y ago
        There is value from the optionality of having a capability even if it isn’t regularly used.
  - jacquesm 4y ago
    That highly depends on who 'we' is. Anybody really in the know is definitely not going to spill the beans. The payload is very small, the stated reasons it flew its missions are 'testbed' for various technologies. Which may well be all there is to it.
  - fragmede 4y ago
    The links to the specific missions on the wikipedia page have some expert conjecture, based on observations by amateur skywatchers, so we have a good idea that it's being used to launch military surveillance and communications satellites, as well as being used to test new hardware. Which is all rather broad and generic, but if it were aliens, it's not like they'd tell us anyway. Even if it were actually confirmed that OTV-1 launched a military surveillance satellite, we still wouldn't know how good it is at that other than some hard limits due to physics (mirror size and atmospheric interference).
  - timschmidt 4y ago
    https://www.youtube.com/watch?v=EQN4hId5psg https://www.youtube.com/watch?v=EQN4hId5psg "Everything We Know About The US Air Force's Secret Space Plane - The X-37B" by Scott Manley
  - Lammy 4y ago
    Obviously total speculation, but it's the right size to be a flying speed-of-light weapon platform. USAF have been interested in such tech for a long time. Some fun links: - Directed Energy Directorate home page during the years 1999–2006: https://web.archive.org/web/20060831035044/http://www.de.afrl.af.mil/ https://web.archive.org/web/20060831035044/http://www.de.afr... - Directed Energy Directorate home page during the years 2009–2016: https://web.archive.org/web/20160428181404/http://www.kirtland.af.mil/afrl_de/ https://web.archive.org/web/20160428181404/http://www.kirtla... - LASER Effects Test Facility fact sheet from 2002 showing a 50-kilowatt CO² LASER setting a test target on fire: https://web.archive.org/web/20070315131556/http://www.de.afrl.af.mil/factsheets/letf.pdf https://web.archive.org/web/20070315131556/http://www.de.afr...
    - nradov 4y ago
      It seems small for any sort of directed energy weapon with a useful power output. There wouldn't be enough capacity for a big generator and heat radiators.
      - Tostino 4y ago
        Right, short of a small reactor onboard, it seems unlikely to be able to store the energy or power densities required while in flight. Obviously there may be some unknown breakthrough that allows it...but I'm skeptical.
  - ceejayoz 4y ago
    One common theory is it's being used to do close-up inspections of other countries' satellites. Bonus points if you can attach a magnetic limpet mine to them for future usage.
    - yetanotherloser 4y ago
      Wouldn't the mass change cause some kind of detectable change in the satellite's trajectory over time?
      - ceejayoz 4y ago
        I don't think anything particularly detectable; they're so outweighed by the planet they're orbiting that the barycenter doesn't move measurably. (To be clear, I'd imagine they're only doing the inspection thing right now, but I do suspect they're at least tinkering with on-orbit capture, refueling, disabling etc. with an arm.)
        dmurray 4y ago
        What if your satellite did some more manoeuvres for station keeping, wouldn't you notice the mass difference then?
        lmm 4y ago
        Maybe. The mass of an explosive could be pretty small compared to the mass of a satellite. And even if you do notice that your (secret military) satellite is slightly heavier than the spec says, what would you do about it?
        matthewdgreen 4y ago
        How expensive is it to attach a couple of space-rated external cameras to a modern satellite? This wouldn’t eliminate the threat but it would certainly remove the uncertainty. Presumably once you recognized the threat, then defending against it couldn’t be the hardest problem to solve.
  - euroderf 4y ago
    It carries a negotiating table. Our telepresence on one side, the aliens['] on the other.
    - simne 4y ago
      Or black box, so they will spend millennia to understand, what we want to say :)))))
      - euroderf 4y ago
        Or... freak out and ATTACK!
- joezydeco 4y ago
  What if the X37B was the imaging satellite?
  - dylan604 4y ago
    Why would they build it to retrieve itself? That's very meta
    - IIAOPSW 4y ago
      Don't you get it. Its shuttles retrieving other shuttles all the way up!
      - dylan604 4y ago
        Russian nesting shuttles?
- ridgeguy 4y ago
  This may be changing with rapid extension of satellite size towards the small end of the spectrum. Small size is now significant. For example, a radar imaging constellation might consist of multiple transmit/receive satellites, each of which could be quite small (say, 1 - 5 cu. ft.). The X37B could accommodate that - especially after it snipped the solar panels off.
the_third_wave 4y ago
If that is its mission the answer is "small payloads" since the carrying capacity of the thing would be quite limited with its 2.1 x 1.2 m [1] payload bay. That leaves little room for the grappling arm or other mechanism needed to pluck a satellite out of its orbit. I suspect it does not retrieve payloads but takes them up and down again. Which payloads? Good question. Experimental sensors meant for inclusion in next-generation reconnaissance satellites maybe? [1] https://web.archive.org/web/20150321121050/http://www.boeing.com/boeing/defense-space/ic/sis/x37b_otv/x37b_otv.page https://web.archive.org/web/20150321121050/http://www.boeing...
hammock 4y ago
https://youtu.be/KZX1YCmzHEw?t=109 https://youtu.be/KZX1YCmzHEw?t=109

The X-37B is much smaller than the shuttle (it was originally intended to fit in the shuttle's payload bay). It physically can't retrieve satellites of any significant size.

kranke155 4y ago
I'm really curious, do we have any idea whatsoever what the X-37 is being used for?
- cjbgkagh 4y ago
  A big advantage of space planes is the ability to change orbit very quickly, could be used for reconnoissance or as a weapons delivery vehicle.
  - the_third_wave 4y ago
    Only if they're in low enough orbits to make use of atmospheric drag. Such orbits decay quickly if the vehicle does not have boost capacity. Given the extremely long missions this thing flies - several missions over 700 days - it seems unlikely for it to make use of atmospheric drag. It might do so when in a highly elliptical orbit but even then it needs to perform a burn at apogee to keep it from re-entering before long.
    - cjbgkagh 4y ago
      There is value from the optionality of having a capability even if it isn’t regularly used.
- jacquesm 4y ago
  That highly depends on who 'we' is. Anybody really in the know is definitely not going to spill the beans. The payload is very small, the stated reasons it flew its missions are 'testbed' for various technologies. Which may well be all there is to it.
- fragmede 4y ago
  The links to the specific missions on the wikipedia page have some expert conjecture, based on observations by amateur skywatchers, so we have a good idea that it's being used to launch military surveillance and communications satellites, as well as being used to test new hardware. Which is all rather broad and generic, but if it were aliens, it's not like they'd tell us anyway. Even if it were actually confirmed that OTV-1 launched a military surveillance satellite, we still wouldn't know how good it is at that other than some hard limits due to physics (mirror size and atmospheric interference).
- timschmidt 4y ago
  https://www.youtube.com/watch?v=EQN4hId5psg https://www.youtube.com/watch?v=EQN4hId5psg "Everything We Know About The US Air Force's Secret Space Plane - The X-37B" by Scott Manley
- Lammy 4y ago
  Obviously total speculation, but it's the right size to be a flying speed-of-light weapon platform. USAF have been interested in such tech for a long time. Some fun links: - Directed Energy Directorate home page during the years 1999–2006: https://web.archive.org/web/20060831035044/http://www.de.afrl.af.mil/ https://web.archive.org/web/20060831035044/http://www.de.afr... - Directed Energy Directorate home page during the years 2009–2016: https://web.archive.org/web/20160428181404/http://www.kirtland.af.mil/afrl_de/ https://web.archive.org/web/20160428181404/http://www.kirtla... - LASER Effects Test Facility fact sheet from 2002 showing a 50-kilowatt CO² LASER setting a test target on fire: https://web.archive.org/web/20070315131556/http://www.de.afrl.af.mil/factsheets/letf.pdf https://web.archive.org/web/20070315131556/http://www.de.afr...
  - nradov 4y ago
    It seems small for any sort of directed energy weapon with a useful power output. There wouldn't be enough capacity for a big generator and heat radiators.
    - Tostino 4y ago
      Right, short of a small reactor onboard, it seems unlikely to be able to store the energy or power densities required while in flight. Obviously there may be some unknown breakthrough that allows it...but I'm skeptical.
- ceejayoz 4y ago
  One common theory is it's being used to do close-up inspections of other countries' satellites. Bonus points if you can attach a magnetic limpet mine to them for future usage.
  - yetanotherloser 4y ago
    Wouldn't the mass change cause some kind of detectable change in the satellite's trajectory over time?
    - ceejayoz 4y ago
      I don't think anything particularly detectable; they're so outweighed by the planet they're orbiting that the barycenter doesn't move measurably. (To be clear, I'd imagine they're only doing the inspection thing right now, but I do suspect they're at least tinkering with on-orbit capture, refueling, disabling etc. with an arm.)
      - dmurray 4y ago
        What if your satellite did some more manoeuvres for station keeping, wouldn't you notice the mass difference then?
        lmm 4y ago
        Maybe. The mass of an explosive could be pretty small compared to the mass of a satellite. And even if you do notice that your (secret military) satellite is slightly heavier than the spec says, what would you do about it?
        matthewdgreen 4y ago
        How expensive is it to attach a couple of space-rated external cameras to a modern satellite? This wouldn’t eliminate the threat but it would certainly remove the uncertainty. Presumably once you recognized the threat, then defending against it couldn’t be the hardest problem to solve.
- euroderf 4y ago
  It carries a negotiating table. Our telepresence on one side, the aliens['] on the other.
  - simne 4y ago
    Or black box, so they will spend millennia to understand, what we want to say :)))))
    - euroderf 4y ago
      Or... freak out and ATTACK!
joezydeco 4y ago
What if the X37B was the imaging satellite?
- dylan604 4y ago
  Why would they build it to retrieve itself? That's very meta
  - IIAOPSW 4y ago
    Don't you get it. Its shuttles retrieving other shuttles all the way up!
    - dylan604 4y ago
      Russian nesting shuttles?
ridgeguy 4y ago
This may be changing with rapid extension of satellite size towards the small end of the spectrum. Small size is now significant. For example, a radar imaging constellation might consist of multiple transmit/receive satellites, each of which could be quite small (say, 1 - 5 cu. ft.). The X37B could accommodate that - especially after it snipped the solar panels off.

the_third_wave 4y ago

If that is its mission the answer is "small payloads" since the carrying capacity of the thing would be quite limited with its 2.1 x 1.2 m [1] payload bay. That leaves little room for the grappling arm or other mechanism needed to pluck a satellite out of its orbit. I suspect it does not retrieve payloads but takes them up and down again. Which payloads? Good question. Experimental sensors meant for inclusion in next-generation reconnaissance satellites maybe? [1] https://web.archive.org/web/20150321121050/http://www.boeing.com/boeing/defense-space/ic/sis/x37b_otv/x37b_otv.page https://web.archive.org/web/20150321121050/http://www.boeing...

hammock 4y ago

https://youtu.be/KZX1YCmzHEw?t=109 https://youtu.be/KZX1YCmzHEw?t=109