I Love Chemically-Fueled, Vertical Take-Off Rockets But Doesn't Humanity Need a More Elegant Way to Get into Space?

[Antares JS]

SpinLaunch is fascinating but could this really be scaled up to handle bigger payloads and orbital launches?
https://www.space.com/spinlaunch-nasa-suborbital-test-flight-agreement

Spin launch is a joke. I could see it being useful for throwing things off the moon, but I'm 99.99% sure it will never work on Earth. The atmosphere will act like a brick wall to anything moving at hypersonic speed coming out of their evacuated centrifuge.

Before anyone says "b-but successful test!" the projectile was pretty clearly not stable and tumbling when it broke through the membrane into the atmosphere.

There is also the issue of the massive g-forces that centrifuge will produce. That environment is not good for delicate satellites.

 

[brockrwood]

Giant, lighter than air, rocket launch platforms floating near the edge of space. Fascinating idea.

—- snip —-
Perhaps the final frontier for airships is space travel, but that is a real possibility. California firm JP Aerospace aims to use airships to carry rockets to the edge of space, where they will gradually accelerate into orbit.
—- snip —-

https://www.discovery.com/science/airships
Just how high can a lighter than air craft go? 90,000 feet?

http://www.jpaerospace.com/ATO/ATO.html

 

[smstachwick]

Giant, lighter than air, rocket launch platforms floating near the edge of space. Fascinating idea.

—- snip —-
Perhaps the final frontier for airships is space travel, but that is a real possibility. California firm JP Aerospace aims to use airships to carry rockets to the edge of space, where they will gradually accelerate into orbit.
—- snip —-

https://www.discovery.com/science/airships
Just how high can a lighter than air craft go? 90,000 feet?

http://www.jpaerospace.com/ATO/ATO.html

Felix Baumgartner’s jump in 2012 was from 127,851 ft.

 

[Antares JS]

Extremely skeptical about this airship thing. Calling even 127,851 feet "the edge of space" is a bit generous. Even if we go by the lower American boundary to space, 50 miles is 264,000 feet. Felix Baumgartner was less than halfway there.

 

[smstachwick]

Extremely skeptical about this airship thing. Calling even 127,851 feet "the edge of space" is a bit generous. Even if we go by the lower American boundary to space, 50 miles is 264,000 feet. Felix Baumgartner was less than halfway there.

People don’t really grasp how huge the atmosphere is or how thin it gets (and stays).

 

[Jeff Lassahn]

It doesn't really matter how close to some arbitrary "edge of space" the balloons can get. The key really crazy idea here is that phrase "gradually accelerate into orbit". They seem to be saying they believe that there's some trajectory from balloon altitude at zero velocity to orbital altitude and velocity where every point along the path has some combination of buoyancy, lift, and centripetal force that's in balance and also survivable in terms of heat load and whatnot. So the balloon ship can work its way along that trajectory at its leisure using low thrust engines.

That's absolutely nuts, but I can't prove it's wrong. If it's actually possible it changes everything about how to get into orbit.

I'd feel a lot better about their chances if the website had some kind of paper or something showing how the math works out.

 

[John Taylor]

[I am re-posting this musing here, as it was starting to get very far afield of the original message thread it was in...]

In the other thread, we were discussing whether Virgin Galactic's "Spaceship 2" is really a spaceship because it does not seem to ever get to the "Karman line" that most experts agree is where Earth's atmosphere ends and "space" begins.

While I admit that some might just dismiss Spaceship 2 as just a really high flying "rocket plane", still, I like the idea of the air-launched "spaceship", a la "Spaceship 2" and the old, venerable, X-15 rocket plane.

It seems to make sense: You make a really big, high-flying, but still air-breathing aircraft. Then you launch or drop a rocket powered "spaceship" from the aircraft. Maybe the spaceship is both "scramjet" and "rocket" craft, or some sort of hybrid. Wouldn't that be the most economical, most elegant way to get into space? Here we are in 2021, 60 years after Yuri Gagarin became the first human in space, and we are still, basically, doing this the same way: We point a large, chemically fueled rocket at the sky and then we light that roman candle. Then the rocket goes (essentially) straight up, vertically, against the gravity well of Earth, expending enormous amounts of fuel in the process. Ultimately, a fairly small payload on the top of the rocket gets into space.

I love rockets! I am a BAR model rocketeer. But as a space enthusiast, I think we ("we" being humanity) need a more elegant way to get into space. Space elevator? Some sort of rail gun that magnetically hurls a payload into space? An air-launched spaceship? A horizontal take off craft that begins as an air-breathing jet airplane, turns into some sort of hybrid jet/rocket craft at some point, and then finally becomes a pure rocket craft that enters space?

No. When you get down to it all is big boys with big toys. The attraction of a big chemical rocket thundering off the pad, muscling it's way upward, expressing all there is to love about the thrust, fire, smoke, and the noise.
Noise so intense they have to flood the exhaust pit with swimming pools full of water every second to suppress the sound vibrations. Otherwise the rocket itself would vibrate apart.
What's not to love about that?

 

[aerostadt]

It doesn't really matter how close to some arbitrary "edge of space" the balloons can get. The key really crazy idea here is that phrase "gradually accelerate into orbit". They seem to be saying they believe that there's some trajectory from balloon altitude at zero velocity to orbital altitude and velocity where every point along the path has some combination of buoyancy, lift, and centripetal force that's in balance and also survivable in terms of heat load and whatnot. So the balloon ship can work its way along that trajectory at its leisure using low thrust engines.

That's absolutely nuts, but I can't prove it's wrong. If it's actually possible it changes everything about how to get into orbit.

I'd feel a lot better about their chances if the website had some kind of paper or something showing how the math works out.

Something like this was posted in TRF years ago. It would be difficult to find now. I am kinda thinking that if this is one of those schemes that we are still talking about and there isn't noticeable progress, there may be no there there. I definitely agree that we would like to see the mathematical analysis on how feasible this is. Even though the air is rarefied at the high altitudes, there can still be lift on a vehicle, but there will be drag, also. So, the analysis would have to show the thrust can provide enough lift and overcome drag to lift the vehicle to a practical orbital altitude and velocity.

 

[techrat]

Here's the thing about vertically launched, chemically fueled rockets. Unless you've got some other way of pushing a few tons into orbit, this seems to be the best way given the technology we've currently got. I mean, if you watch these launches, you'll notice they are going supersonic less than 90 seconds from leaving the pad. Very little gets to that kind of speed so quickly, and remember that to even get anywhere near orbital velocities you're talking about at least 17,000 mph.

There's that spin-launch system they are trying out, but, unless you're willing to try nuclear powered rockets, it just takes a massive amount of energy to push against Earth's gravity well. And for that, all we've got currently is controlled explosive fuel. While I would love for some newfangled physics to come about, so far, none of it has become technically feasible.