I'm mainly surprised that we have reusable space planes at all. You'd think that would get more attention.
Experimental USAF space plane breaks record for orbital spaceflight
41–50 of 114 posts
Re: Experimental USAF space plane breaks record for orbital spaceflight
#42Obvious 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…
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…
Yes, orbital mechanics are very non-intuitive.
Thinking "you're in space so can go anywhere" makes as much sense as thinking it's easy to go from Canada to the top of the Everest just because they're both on land.
Re: Experimental USAF space plane breaks record for orbital spaceflight
#43> breaks record of orbital spaceflight It broke it's own record of "time-in-orbit" and as far as spaceflight records go this is one of the least relevant. Once a spacecraft gets to orbit it is very easy to stay there almost indefinitely. Hell, the ISS breaks the record for "continuous habitation in orbit" every day.
While true, and I see your point, it's also worth pointing out: the ISS doesn't need to make any trips back down again. This is a re-usable spaceship, albeit one humans don't get to ride in.
The ISS problem is arguably harder. It doesn't need to survive reentry but you also can't take the whole thing apart, clean it, and put it back together again in a nice climate-controlled machine shop. You have to do it in cramped zero-gravity and keep most of the systems online while you're doing it.
Re: Experimental USAF space plane breaks record for orbital spaceflight
#44Excellent. Never the less, still super curious about the tictac thing. :)
Re: Experimental USAF space plane breaks record for orbital spaceflight
#45Obvious 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…
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 repeatedly change orbit around earth, provided you have an abundant energy source?
Re: Experimental USAF space plane breaks record for orbital spaceflight
#46Earlier quoted context omitted.
The U.S. Air Force's former top civilian, Heather Wilson, said it dips into the atmosphere and uses its aerodynamic surfaces to change its orbit. Ref: https://www.military.com/daily-news/2019/07/23/former-secaf-...
There's no free lunch in orbit. If it dips into the atmosphere enough for control surfaces to bite then it has to boost back up again to avoid orbital decay. Either way it can't possibly carry enough fuel to do much of that.
> it has to boost back up again to avoid orbital decay
It doesn’t have to return to orbit. Switching from an orbital trajectory to a parabolic intercept path would be feasible, and open valuable tactical space.
Re: Experimental USAF space plane breaks record for orbital spaceflight
#47Obvious 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…
Literally all of these could occur more cheaply without deorbiting the spacecraft.
"Bringing back an opponent's satellite for examination"...
Re: Experimental USAF space plane breaks record for orbital spaceflight
#48Earlier quoted context omitted.
Nah. Bolt cutters on an arm, or even just spray paint. You don’t need to be close to do an electronic attack. If you’re close, you might as well hit it with a hammer or snip the antenna and solar arrays off.
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...
Re: Experimental USAF space plane breaks record for orbital spaceflight
#49> NASA began the X-37 program in 1999;
Maybe officially, but I definitely know people who were working on a Space Plane program in the early 90s.
Re: Experimental USAF space plane breaks record for orbital spaceflight
#50Earlier quoted context omitted.
"Liberator"
Hold still while I freedom you!
Could you please review the site guidelines and not post unsubstantive comments to HN? We ban accounts that repeatedly do that because we're trying for a bit better than internet default here.