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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

#21

Post by jfoutz »

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

Well, Restore-L looks to service satellites not designed for service. If you knew the X-37 was coming, and you knew it was a flying gas station, i'd bet that problem is far far easier. You don't have to take the target apart in space and put it back together. On the other hand, an easily accessible common connector seems like something we could have standardized on and implemented 15-20 years ago.

Again, i have no evidence of any of this. But it's my favorite pet theory.

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

#22

Post by wolf550e »

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...

SNC are building a small shuttle-like thing that lands gently on a runway. they planned to build a crewed version, but lost the NASA competition to SpaceX and Boeing. They won a contract for cargo, with an unmanned variant, possibly because NASA is really interested in "dissimilar redundancy".

https://en.wikipedia.org/wiki/Dream_Chaser

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

#23

Post by robotresearcher »

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.

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.

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

#25

Post by theoh »

blackguardx wrote: post #17
jessriedel wrote: post #15

Earlier quoted context omitted.

Yea, wings on spacecraft are about as elegant as parachutes. They can make sense for certain uses, but, as a rule of thumb, they are inelegant and not futuristic.

Technically, the space shuttle and this space plane are lifting bodies, which I think is pretty cool and elegant.

... there's something particularly evocative about this image taken during early lifting body research: https://www.nasa.gov/centers/dryden/multimedia/imagegallery/...

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

#26

Post by bediger4000 »

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 cost of the program is also classified." - naturally! As someone much, much smarter than me noted, there's very few real state secrets, but there's tons of career-ending blunders, accounting mistakes, ridiculous overcharging and independent validation and verification companies that just happen to be owned by a distant relative. Those categories are not mutually exclusive.

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

#27

Post by Retric »

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.

These things would fit inside the shuttle which creates a very different design with much lower thermal stresses.

Remember, the initial shuttle design was actually viewed as an improvement by real rockets scientists even if the project ballooned into ridiculous territory there really is a lot of value in those short stubby wings.

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

#28

Post by kens »

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…

My assumption is that "perform risk reduction" means "try things out to make sure they will work when we use them later". For instance, now they have more confidence that they can leave the spaceship orbiting for two years without something breaking. Kind of like Apollo 8 (fly around the moon without landing) was risk reduction for Apollo 11 (land on the moon).

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

#29

Post by wolf550e »

azinman2 wrote: post #10
Animats wrote: post #5

Earlier quoted context omitted.

Toxic propellants. Nitrogen tetroxide / hydrazine. Both components are highly toxic. The big space shuttle used those for its maneuvering propulsion, and ground crews had to wear all the protective gear after landing until the propellant had been drained.

Is it all combusted perfectly, or do they lose some and just leave droplets of toxic liquid propellant in their paths as they fly?

The combustion byproducts are toxic and some uncombusted propellants are left in the pipes and can leak out. Has to be washed.

The emergency APU on F-16 fighters uses hydrazine and if it was used and the jet landed on a civilian airport (e.g. engine failure) then you need to have it safely washed before anyone can approach the plane. https://youtu.be/Puia_yQxir8?t=178

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

#30

Post by JacobDotVI »

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 can be thought of finding a cheaper / faster / easier way to test a hypothesis than performing a full experiment. Think of it like surveying a sample instead of a population.
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