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Unmanned U.S. Air Force space plane lands after secret, two-year mission

reuters.com

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Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#41

Post by ceejayoz »

robotresearcher wrote: post #23
colordrops wrote: post #13

Earlier quoted context omitted.

Capsules aren't inferior. In fact they can land on planets and moons without atmospheres, unlike space planes. And once propulsive landing of capsules is implemented, they can land on Earth without a landing strip, and even on boats.

Capsules like Soyuz can't land without an atmosphere. They use aerobraking and parachutes. You need a big rocket to slow down and land. At which point it's a very different machine.

I'd imagine the grandparent is thinking more SpaceX than Soyuz.

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#42

Post by maxander »

robotresearcher wrote: post #23
colordrops wrote: post #13

Earlier quoted context omitted.

Capsules aren't inferior. In fact they can land on planets and moons without atmospheres, unlike space planes. And once propulsive landing of capsules is implemented, they can land on Earth without a landing strip, and even on boats.

Capsules like Soyuz can't land without an atmosphere. They use aerobraking and parachutes. You need a big rocket to slow down and land. At which point it's a very different machine.

SpaceX's Dragon capsules come with engines, which (in some configurations) are sufficient for powered landings. And it's still called a "capsule."

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#43

Post by ceejayoz »

gibsjose wrote: post #18
jfoutz wrote: post #14

Earlier quoted context omitted.

My guess was to refuel spy satellites. I imagine those sats are tough and can survive a long time. But when they get low on gas they can only do station keeping. If you can count of fuel coming, there's a lot more freedom to shift the track a half a degree as needed. It may be all electronic surveillance. I guess, you can count on satellites not changing after they're launched, so the electronics package would be goo…

On-orbit satellite servicing and refueling has not been performed as of yet, but we are currently working on it: https://sspd.gsfc.nasa.gov/restore-l.html

> On-orbit satellite servicing and refueling has not been performed as of yet

Declassified on-orbit satellite servicing and refueling has not been performed as of yet. I wouldn't be shocked if the X-37 has refueled a NRO bird or two (or just simulated it) as a test.

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#44

Post by jcurbo »

bediger4000 wrote: post #26

I like the semi-gibberish official explanation: The orbiters "perform risk reduction, experimentation and concept-of-operations development for reusable space vehicle technologies," the Air Force has said without providing details. The cost of the program is also classified. How, pray tell, does anything "perform risk reduction"? Does that phrase have any meaning in English, or any other terrestrial language? "The co…

Risk reduction - pretty well explained above. Experimentation - Standard definition. Trying out stuff. Concept-of-operations development - take the experiments and turn them into instructions and procedures for normal operations. Think of it as production compared to experimentation being dev. (concept of operations is a standard document describing the 'how' of something, typically in a tech-agnostic way)

Basically they are using this vehicle to figure out how to do this stuff with future vehicles in a scaled-up way.

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#46

Post by ceejayoz »

compton_effect wrote: post #39
tammer wrote: post #20

Surprised nobody's mentioned this possibility as it usually comes up re: the X-37B. Terrifying but I think not out of the question given the strategic potential of such a weapon. https://en.wikipedia.org/wiki/Kinetic_bombardment

cool idea but I'm gonna assume its a lot more expensive to send up an X-37 and have it crash back down then it is too just send a few nukes at your target.

If you look at it purely from a costs perspective, maybe.

Don't discount the PR disaster that would ensue from the US using nukes in any scenario other than retaliation for a nuclear attack. Nukes used in anger would likely mean worldwide condemnation, sanctions, and pissed allies complaining about fallout.

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#47

Post by dogma1138 »

ceejayoz wrote: post #41
robotresearcher wrote: post #23

Earlier quoted context omitted.

Capsules like Soyuz can't land without an atmosphere. They use aerobraking and parachutes. You need a big rocket to slow down and land. At which point it's a very different machine.

I'd imagine the grandparent is thinking more SpaceX than Soyuz.

SpaceX Dragon capsule can't land without atmosphere either it needs it to aerobreak it doesn't carry nearly enough fuel to come to a rest from orbital reentry speeds using propulsion alone.

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#48

Post by jessaustin »

JshWright wrote: post #36
jcims wrote: post #12

Earlier quoted context omitted.

I always imagine it creeping up on unsuspecting satellites like some kind of space puma. All up close and personal like, giving them a sniff and then slipping away undetected.

It's tough to be sneaky in space...

If the satellite has "local" sensing equipment, then sure there's nowhere to hide. How many satellites have that? If such sensors aren't installed, it's not like anyone down here on the ground will notice. If someone did notice, what could they do in response? Complain to the media?

Re: Unmanned U.S. Air Force space plane lands after secret, two-year mission

#49

Post by ceejayoz »

dogma1138 wrote: post #47
ceejayoz wrote: post #41

Earlier quoted context omitted.

I'd imagine the grandparent is thinking more SpaceX than Soyuz.

SpaceX Dragon capsule can't land without atmosphere either it needs it to aerobreak it doesn't carry nearly enough fuel to come to a rest from orbital reentry speeds using propulsion alone.

https://www.quora.com/Can-the-Dragon-V2-land-on-the-moon

> The Dragon-2 has enough power and fuel to land and ascend back to lunar orbit. The Dragon's SuperDraco has higher performance than the Apollo Lunar Module. Apollo LM descent engines has 10,000 lbf thrust, and 3,500 lbf thrust for ascent (the lander part is left behind). The Dragon's SuperDraco has 16,000 lbf thrust. The Dragon also uses computers to control throttle and land (much more fuel efficient). Hence, the Dragon-2 has enough power and fuel to land and ascend back to lunar orbit even if it carries all it's parts during ascent. However, it may need to cut crew from 7 to 3 to loose more weight for fuel.

(Plus, I said "more SpaceX" as in "capsules with powered descent", not "SpaceX's exact current models as already implemented"...)

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