Single-stage-to-orbit has been a dream for spaceflight for generations. It could seriously lower the cost of getting payloads to orbit.
It may yet happen.
Radian Aerospace has a handful of engineers, far fewer than they will need to build something that flies. But they have a neat concept. It would be fantastic if they can pull this off.
Refunder Blunder, Part 77
34 minutes ago
10 comments:
I read about that earlier today and agree, this might be what gets it done. Funny how RAH used to talk about doing all of that off of Pikes Peak. I like the ground-based sled ideal better.
Link's busted. They talking about the railgun method?
I guess they’ve been hit with something.
try this. The plane would launch from a rocket-sled, sort of a glorified catapult.
Sort of like the early Wright Flyers.
https://www.geekwire.com/2022/radian-aerospace-comes-out-of-stealth-and-raises-27-5m-for-orbital-space-plane-development
I keep having visions of a '67 Chevy with a jet strapped to the roof.
The spaceplane is not a new concept, I don't think that graphic is "new"; it is unfortunate that the launch system captures the attention, where the real story is in the prototype rockets. It's the way it's written, like a better explanation got edited and what was left got tagged on to the end of another, semi-related sentence. Grant there have been improvements to rail tech over the Wrights, or the stuff my step-father was working with at Edwards in the sixties, but the physics of it all in my mind have it tearing up the tracks behind it before it gains lift velocity.
A magnetic railgun, OTOH, get's complicated quick, but a shot up Pike's Peak was mentioned somewhere, sometime; may have been grain-of-salt. More famous as a moon-weapon.
As an old lift-tech my attention was captured by the 5,000 lb payload ...
TB: “The Moon is a Harsh Mistress”?
Yes, though a better representation in popular culture would be the Viper launch tubes in the original Battlestar. Dropping rocks on the ... recalcitrant, fired out/off of a repurposed magnetic "rail" gun running miles across the lunar, ahhhh, moonscape. Not necessarily on a rail, but following a track system of magnets (at polarity with the magnetic hulls of the cargo pods it was launching).
In the sixties there was talk of building something like that up Pike's Peak, but it was determined it wouldn't achieve escape velocity.
The problem is energy needed vs energy imparted plus energy carried.
That is just to get to orbit at 17++KMPH, suborbital is far less.
Fastest air breathing bird is the X34A at almost mach 10 and 110,000ft
(20mi). A mig made it to 123,000 fett for a record. X15 made it to
340,000 but less than mach 3. At most those were suborbital parabolas.
The special sauce is enough velocity from the ground level and a fuel
that is energy dense enough to add to that. To come down from orbit
you first need to slow down, takes a air amount of energy to combat
inertia (see shuttle OMS engines), That and the slower you get to
in space the slower you are in air lest it burn you up. The shuttle
was a balancing act enough fuel and thrust to slow down and enough
Thermal surface to take the considerable heat.
That suggests saving fuel going up is helpful. but current fuels
with oxidizer to continue are require bulk and weight.
Right now the Falcon-9 booster (only) in a full effort can make
LEO with essentially no fuel left and no payload. MECO for the
Falcon-9 is about or above 50 miles at Mach 10 speed in order
to land and it retains about 2% of its total fuel decelerate
and to land.
So to fly to space (orbit) you need to launch faster than SR71
and have enough fuel and engine in air to get to greater than
mach 10 and 120,000 ft while fighting gravity and drag, where
enough fuel and oxidizer to continue as air is then in very
short supply to burn. Then you need enough fuel for return
and reaction controls as wings at 25++ miles altitude are
really mostly useless and above 80 miles just dead weight
till you get down into the air thick enough to make them
useful again.
In all cases the first 15 to 20 miles of altitude are the
hardest, it limits speed due to drag and heating. Current
tech (falcon 9) eats nearly half of its fuel (booster)
getting to that level.
SSO requires some tech we don't have. Most SiFi sorta
skirts that or implies deriving it from the atoms itself.
Eck!
Oh! I thought that was going to be about that nifty why-not-I-ask-you yeet approach, where they strap you into a centrifuge and whirl you up to near escape velocity. I'd be happy to go, except for the fact that at my age 500 times the force of gravity might be a bit over my limits.
https://www.gizmodo.com.au/2021/11/this-company-wants-to-launch-satellites-into-orbit-using-a-giant-spinning-centrifugal-slingshot/
I remember something back in the 1980s where a pressurized gas cannon method was proposed, but not for spaceflight, more for launching satellites and space station supplies. It ended up getting designed as a long-range artillery piece for Iraq before the 1991 war.
https://en.wikipedia.org/wiki/Project_Babylon
If it's similar, the cannon is going to need to be wider, and far longer - no jokes, please - than the 150 ft. cannon Iraq had.
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