Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

reuters.com

Post reply on HN
Print view View original

71–80 of 177 posts

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

#71

Post by exabrial »

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.

Clearly you've never needed to plant a nuclear bomb on an asteroid hurtling towards the Earth.

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

#72

Post by anarazel »

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.

Preface: I don't think this is a likely explanation.

But if you think it is, there's a big advantage of kinetic weapons over ICBMs, namely that they are a lot more credible as a first strike weapon. ICBMs launches are quite detectable, allowing counter strikes (hi there nuclear deterrence).

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

#73

Post by mapt »

sandworm101 wrote: post #70
mapt wrote: post #66

Earlier quoted context omitted.

The driving requirement of the Shuttle was that it should be feasible to steal a Soviet satellite sporting unknown new orbital technology, before the Soviets had the opportunity to intervene, and that it be prepared to fly fairly quickly whatever its faults to be ready for potential Soviet expansions into spaceflight as an area of competition. There were a lot of other requirements and stakeholders that were part of…

Nobody seriously though Shuttle could bring back a hostile spacecraft. The logistics of such a thing are ridiculous. What Shuttle could have done was to bring back friendly sats. The only friendly sats worth bringing back would be something that couldn't be allowed to re-enter. The only things that couldn't ever be allowed to re-enter would be something nuclear, either a reactor or a bomb. Shuttle was envisioned as a…

Such a system could orbit a number of times during maintenance operations of friendly satellites; It would not need the cross-range that the Shuttle was built for.

I get a lot of "Nobody seriously thought this", but the high cross-range required of single-orbit-and-land is the long pole in the tent that stretches the rest of the requirements; It's not a reasonable tradeoff unless espionage was a use-case that could not be ruled out.

Without the requirement to land a large cargo bay with an extreme cross-range, the optimal design looks nothing like the Shuttle. The Shuttle cost an order of magnitude more than that optimal design.

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

#74

Post by jjoonathan »

taneq wrote: post #65
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

People always talk about kinetic strikes in the context of big flashy things like rockets and spaceplanes. I'd be a lot more worried about them being dropped from stratospheric balloons - maybe not so useful for full scale bunker busting but extremely cheap to make and almost indefensible against as a strategic strike system.

Err, shoot the balloons?

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

#75

Post by nradov »

bjd2385 wrote: post #16
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.

Way I see it is, if we can land a rover the size of a minivan on a different planet, we should be able to do this without much more effort. Money, perhaps, yes; but, we've already done it.

You might think so, but the difficulty doesn't scale linearly with size and weight. For example there's a practical upper bound on airbags to absorb landing shock; we can't just build larger ones for a capsule carrying humans.

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

#76

Post by taneq »

jjoonathan wrote: post #74
taneq wrote: post #65

Earlier quoted context omitted.

People always talk about kinetic strikes in the context of big flashy things like rockets and spaceplanes. I'd be a lot more worried about them being dropped from stratospheric balloons - maybe not so useful for full scale bunker busting but extremely cheap to make and almost indefensible against as a strategic strike system.

Err, shoot the balloons?

60+ km straight up is a long way to shoot.

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

#77

Post by nradov »

mapt wrote: post #66
sandworm101 wrote: post #58

Earlier quoted context omitted.

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…

The driving requirement of the Shuttle was that it should be feasible to steal a Soviet satellite sporting unknown new orbital technology, before the Soviets had the opportunity to intervene, and that it be prepared to fly fairly quickly whatever its faults to be ready for potential Soviet expansions into spaceflight as an area of competition. There were a lot of other requirements and stakeholders that were part of…

That's completely wrong. There was no serious consideration of stealing Soviet satellites. Everyone knew that we'd never be able to get away with that.

The driving requirement was to act as a successor to the SR-71. Launch, make a single reconnaissance pass over the Soviet Union, and then utilize the cross-range capability to land immediately so that the film could be developed. But by the time the Shuttle was actually built, spy satellites equipped with digital cameras had improved so much that it became moot.

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

#78

Post by dpc59 »

jjoonathan wrote: post #74
taneq wrote: post #65

Earlier quoted context omitted.

People always talk about kinetic strikes in the context of big flashy things like rockets and spaceplanes. I'd be a lot more worried about them being dropped from stratospheric balloons - maybe not so useful for full scale bunker busting but extremely cheap to make and almost indefensible against as a strategic strike system.

Err, shoot the balloons?

The ressources required to shoot stuff that's in the stratosphere are on a whole other ballpark than what your average revolutionaries can do.

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

#79

Post by nradov »

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

Orbital kinetic bombardment is a silly concept suitable only for cheap sci-fi novels. There's no benefit in having kinetic weapons permanently positioned in orbit. The satellites would be easily tracked and vulnerable to ASAT weapons. They can't strike a target much faster than a ballistic missile launched from land or sea. And they would be much more expensive. Anything in orbit is out of reach of maintenance. It takes a lot of energy to get a satellite into a stable orbit, and then yet more energy to de-orbit a missile.

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

#80

Post by joshschreuder »

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

> During the Vietnam War, there was limited use of the Lazy Dog bomb, a steel projectile shaped like a conventional bomb but only about 1" long and 3/8" diameter. A piece of sheet metal was folded to make the fins and welded to the rear of the projectile. These were dumped from aircraft onto enemy troops and had the same effect as a machine gun fired vertically.[3][4] Observers visiting a battlefield after an attack said it looked like the ground had been 'tenderized' using a gigantic fork. Bodies had been penetrated longitudinally from shoulder to lower abdomen

That is utterly terrifying.

Post reply on HN