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Experimental USAF space plane breaks record for orbital spaceflight

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Re: Experimental USAF space plane breaks record for orbital spaceflight

#91

Post by mabbo »

TeMPOraL wrote: post #84
riffraff wrote: post #79

Earlier quoted context omitted.

this still gets launched with a rocket, it's basically a very small unmanned space shuttle, so it's not as "cool" as, say, something that goes to orbit from the ground on its own.

Are single-stage to orbit (SSTO) spaceplanes even possible on Earth with current chemical rockets? They're a PITA to build in Kerbal Space Program, and there the universe is 1/10 the size of the real one (albeit with the same gravitational acceleration).

They are possible, but not economically feasible. Tim Dodd has a fantastic video showing just how ineffective they are.

Two (or three) stage rockets are just so much more efficient.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#92

Post by twic »

exabrial wrote: post #65
colechristensen wrote: post #16

Obvious missions for a long-mission mobile shuttle like this include * intercepting and deorbiting space junk * fixing friendly or sabotaging unfriendly operational satellites * future weapons platform for offense or defense (say intercepting ground-launched sat-killing missiles) * on-demand surveillance (with ordinary spy satellites you have to wait until your orbit is in the right spot, adversaries will know when y…

Sorry to burst your bubble, but the satellite bandwidth just isn't there yet for Netflix at an affordable rate.

So they must be using physical DVDs, interesting.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#93

Post by LeonM »

colechristensen wrote: post #16

Obvious missions for a long-mission mobile shuttle like this include * intercepting and deorbiting space junk * fixing friendly or sabotaging unfriendly operational satellites * future weapons platform for offense or defense (say intercepting ground-launched sat-killing missiles) * on-demand surveillance (with ordinary spy satellites you have to wait until your orbit is in the right spot, adversaries will know when y…

> Prep for mining activities further out

AFAIK there is not a single element that is valuable enough to offset the gigantic costs of mining in space and moving bulk back to earth. The economics just don't work.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#95

Post by dexen »

rezeroed wrote: post #94

Why does the vehicle look rusty? And what the the duct tape looking stuff on the wing leading edge?

The vehicle in the photo has clearly been processed, and is ready for handling or shipping. Not sure if the photo is after-flight or perhaps before.

>rusty

The "rusty" parts look like crevices between protective tiles being sealed with kapton tape[1] - general protective material that handles well extreme environment, and is often used in consumer electronics, especially in places where high temperatures are expected.

>duct tape looking stuff on the wing leading edge

Looks like temporary protective coating of foam, for safe on the ground handling, to prevent damage to the wing leading edge. If the leading edge is anything similar to Space Shuttle's, it's hollow inside, surprisingly thin, and somewhat brittle. Any cracks or damage would cause risk of overheating during re-entry, thus need for extra protection. --

[1] https://en.wikipedia.org/wiki/Kapton

Re: Experimental USAF space plane breaks record for orbital spaceflight

#97

Post by nine_k »

bigiain wrote: post #48
nine_k wrote: post #35

Earlier quoted context omitted.

This kind of sudden malfunction, along with acceleration not due to firing of any engines, would be a signal for the self-destruction device, likely chemically powered (explosive) and mechanically actuated. It would be sure to shatter the interesting electronic parts, burning or detonating any remaining fuel for bonus points.

I suspect the arguments about how much launch mass to devote to self destruct explosive and mechanism - compared to useful payload or manoeuvring propellant - would be interesting to see...

You need an ounce or two of HE, strategically placed, to destroy the sensitive parts with confidence. Nobody needs to shatter the entire satellite to pieces.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#98

Post by nine_k »

jonathankoren wrote: post #62
nine_k wrote: post #35

Earlier quoted context omitted.

This kind of sudden malfunction, along with acceleration not due to firing of any engines, would be a signal for the self-destruction device, likely chemically powered (explosive) and mechanically actuated. It would be sure to shatter the interesting electronic parts, burning or detonating any remaining fuel for bonus points.

I would be very surprised if any orbiting spacecraft built today, or currently being planned has any sort of self destruct. We're talking about capabilities that are still theoretical, albeit pretty plausible and feasible. Anyway, who cares if the self destruct goes off? You're breaking the satellite anyway, and if you were really concerned, about attacker survivability, just launch a gun on board, like Salyut 3. htt…

Indeed; there are many cheaper ways to destroy a satellite, and (IDK if cheaper) air-to-space anti-sat missiles are in service for decades.

Re: Experimental USAF space plane breaks record for orbital spaceflight

#99

Post by _Microft »

tech_yogi wrote: post #45
Tuxer wrote: post #19

Earlier quoted context omitted.

Space isn't like a highway where you can move from A to B at minimal expense. Switching orbits, both orbit heights but mainly orbit inclinations, comes at a very high delta-V expense and therefore propellant expense, which this craft simply doesn't have the volume to hold. This cannot shuttle between LEO stations and switch orbits to imitate multiple observation sats unless those sats and stations are very close in t…

Could it "scoop" matter out of the atmosphere that could be accelerated by solar or nuclear powered ion drive to use as propellant? Alternatively, thinking about the Earth's magnetic field, what if it had a big current loop that could be activated to generate a force and change orbit. I realize that the magnitude of these effects are probably too small to be significant, but could you in principle use them to repeate…

The ESA is developing an air-breathing electric thruster which sounds what you described:

http://www.esa.int/Our_Activities/Space_Engineering_Technolo...

Re: Experimental USAF space plane breaks record for orbital spaceflight

#100

Post by SEJeff »

TeMPOraL wrote: post #84
riffraff wrote: post #79

Earlier quoted context omitted.

this still gets launched with a rocket, it's basically a very small unmanned space shuttle, so it's not as "cool" as, say, something that goes to orbit from the ground on its own.

Are single-stage to orbit (SSTO) spaceplanes even possible on Earth with current chemical rockets? They're a PITA to build in Kerbal Space Program, and there the universe is 1/10 the size of the real one (albeit with the same gravitational acceleration).

There was a lot of discussion after Elon Musk said that Starship (aka the BFS aka Big "Falcon" Spaceship aka the second stage of their starship) will be able to do SSTO, however it would only be able to SSTO with virtually zero payload whatsoever, so isn't very useful.
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