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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

#51

Post by dogma1138 »

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

Hubble fixes? Also it seems that quite a few shuttle missions were satellite servicing missions including relaunching sattlites that failed to get into the correct orbit: https://en.m.wikipedia.org/wiki/STS-49

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

#52

Post by maverick_iceman »

jcims wrote: post #12
Animats wrote: post #2

Whatever the X-37B does, it seems to do it very well. This is its fourth mission. Missions - that don't need people - are the luckiest missions in the world..

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.

What would be the point?

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

#53

Post by dogma1138 »

ceejayoz wrote: post #49
dogma1138 wrote: post #47

Earlier quoted context omitted.

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 t…

Lunar orbit isn't earth reentry tho, even the SuperDraco doesn't seem to carry enough fuel nor have the specific impulse for an earth landing when you remove the aerobreaking.

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

#54

Post by sandworm101 »

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

Refuelling sats won't ever be a thing. There is no real need. Any refuelling vehicle will need it's own propulsion/rcs system and a docking scheme. Once docked and/or latched onto the target ... job done. The refuelling vessel becomes the new orbital manoeuvring system for the depleted sat. Cost wise, that makes more sense than having a large tanker bouncing around between clients. With the switch to ion propulsion total fuel may also not be the limiting factor. Ion thrusters can become very inefficient and/or useless after years in space. Flying up and bolting on a new rig is simpler than trying to actually service/replace such parts.

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

#55

Post by dogma1138 »

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

Look at the payload capacity of the X37 it would do about as much damage as a bunker buster.

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

#56

Post by dtparr »

jessaustin wrote: post #48
JshWright wrote: post #36

Earlier quoted context omitted.

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?

Actually, most objects of any size are actively tracked pretty much continually from the ground. That's especially true of a state's classified space plane.

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

#57

Post by ceejayoz »

dogma1138 wrote: post #53
ceejayoz wrote: post #49

Earlier quoted context omitted.

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 t…

Lunar orbit isn't earth reentry tho, even the SuperDraco doesn't seem to carry enough fuel nor have the specific impulse for an earth landing when you remove the aerobreaking.

OK? I'm not sure what point you're trying to make, then, as there's not a no-atmosphere, Earth-sized body in the solar system for your argument to apply to.

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

#58

Post by sandworm101 »

colordrops wrote: post #13
Animats wrote: post #9

This is the X-37B. There's a contract for an X-37C, 1.8x as big and possibly capable of carrying humans.[1] That would be a nice little spacecraft. It's time to get past capsules, without building something as big and fragile as the Space Shuttle. The USAF and Boeing aren't saying much about it, though. [1] http://www.spacesafetymagazine.com/aerospace-engineering/spa...

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.

There are a few things that wings can do that capsules cannot. Shuttle's wing were never actually used for their intended purpose. Wings allow for "once over and return" flights. Shuttle's creators envisioned it launching into a polar orbit, overflying the USSR to [redacted] then land back home without a second orbit. That requires the ability to 'fly' through the atmosphere to make up for the earth's rotation during your orbit. For a vehicle doing multiple orbits, such wings would allow it greater latitude on return. It wouldn't have to wait for its orbit to line up as perfectly with the intended landing site.

"The militarily specified 1,085 nmi (2,009 km; 1,249 mi) cross range requirement was one of the primary reasons for the Shuttle's large wings, compared to modern commercial designs with very minimal control surfaces and glide capability." https://en.wikipedia.org/wiki/Space_Shuttle

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

#59

Post by trothamel »

jessaustin wrote: post #48
JshWright wrote: post #36

Earlier quoted context omitted.

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?

Actually, it's pretty easy to keep track of the X-37. You could see where it would have been had it not landed here:

http://www.heavens-above.com/orbit.aspx?satid=40651&lat=0&ln...

If it was to get close to a non-US military satellite, one could expect people to complain diplomatically, at least.

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

#60

Post by matt4077 »

wolf550e wrote: post #33
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 is a completely normal term in R&D. It just means experiment to raise confidence in a particular proposed approach, before going full scale production. It is meant to raise the TRL[1] of a technology, to gain experience with it. In my software day job, we write throw away code to test out an idea, and we call it proof of concept. It is used to find out early if the schedule for a feature is too optimis…

i feel like it should be "reduce risk" instead of "perform risk reduction", but I guess I can see that these (now?) mean slightly different things.
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