Blue Origins, update Options

[edstrick]

I have wondered if a 2 stage double DC-X type might be able to launch from Texas and land the first stage in Florida, but I think that's decidedly too long a hop for even a long-throw first stage. I'd like to see some calculations. A DC-X type first stage could do a partially fueled reverse hop from a downrange landing site to get back to it's primary launch site.

[Bob Shaw]

I think the word you're looking for is 'Kistler'!


Bob Shaw

[edstrick]

The Kstler vehicles are being soft <parachute and airbag?> landed, but not as VTVL vehicles. I don't know good details on their design, especially first stage landing and second stage re-entry and landing, but I wish them success.

[djellison]

With such high gravity to fight against, and a nice thick atmosphere that's screaming out for chutes, parafoils etc.... landing with rockets on Earth just doesn't make a lot of sense to me.

Doug

[AndyG]

[L]anding with rockets on Earth just doesn't make a lot of sense to me.

I agree.

Using one of the fresh envelope-backs I got for Christmas, I see that retro-rocket-landing an Apollo CM from the drogue release altitude and speed, for example, would require something like a beefed-up AJ10-137 engine (massing around 4000kg), 31 seconds' thrust (1450 kg of fuel and oxidiser), all crammed into a 5800 kg mass capsule (!!). Naturally the engine would have to poke through the heat shield, which additionally complicates matters.

Comparing that to the (original) 245kg parachutes-and-drogues-and-deployment package, it's an absolute no-brainer.

<long pause>

...though, in its favour <whispering> it would look rather Heinleinian.

Andy

[mcaplinger]

Comparing that to the (original) 245kg parachutes-and-drogues-and-deployment package, it's an absolute no-brainer.

If you're never going to use the vehicle again, absolutely.

The arguments for VTVL all revolve around reusability and rapid turnaround. See, for example, http://www.thespacereview.com/article/412/1

I'm agnostic on the topic; like most engineering, there is no clear best solution. It's very dependent on the mission profile and on the logistical/economic assumptions.

[climber]

If you're never going to use the vehicle again, absolutely.
I'm agnostic on the topic; like most engineering, there is no clear best solution. It's very dependent on the mission profile and on the logistical/economic assumptions.

I agree but I also wonder if a Soyouz-like last seconds hard brake retro-rocket solution could be used. There's no need here to have a "smooth" hard-brake since there's nobody inside. Is they can get the retro rocket working in the good force vector and then inflate air bags so the stage doen't hit too hard, I bet it'll not be too much of an extra weight as compared to reusability. And it'll be an elegant solution.

[Bob Shaw]

I agree but I also wonder if a Soyouz-like last seconds hard brake retro-rocket solution could be used. There's no need here to have a "smooth" hard-brake since there's nobody inside. Is they can get the retro rocket working in the good force vector and then inflate air bags so the stage doen't hit too hard, I bet it'll not be too much of an extra weight as compared to reusability. And it'll be an elegant solution.

Or there's the scheme for the Energia boosters, which would have landed under parachutes on Rogallo Gemini-style outriggers (you know what I mean!) and with the final impact cushioned by solid rockets. That gear is what all the square lumps were on the side of the Energia boosters - sadly, of course, never to be used in anger. So a liquid fuel first-stage land recovery system for *big* vehicles has already been built (and the boosters continue to fly in the form of Tsyklon). I was told years ago by Gerry Webb (at that time he was very cosy with the ex-Soviet rocketeers) that the core stage could also be recovered, but I've never found any references to that elsewhere.

Bob Shaw

[mchan]

So a liquid fuel first-stage land recovery system for *big* vehicles has already been built (and the boosters continue to fly in the form of Tsyklon).

Ahh, Zenit?

[Bob Shaw]

Ahh, Zenit?

Absolutely. My rocketry database hit a nadir!

Nil Points!


Bob Shaw

[Jim from NSF.com]

Yeah (sigh), that's probably quite true; a useful payload in all likelihood cannot be delivered via this method. Again, I'll speak to him next week & we'll play with the numbers some more; he's considering this as a thesis topic. Thanks Bob & remcook for your valuable critical commentary!

Thesis? The idea shouldn't have even got past the back of the envelope, much less an idea for a thesis. Somebody's engineering education is severely lacking. If this is the type of people in AFSPACECOM, then our military space cadre is in worse shape than in the 90's (which was worse than any point in history)

This proposal is similar to the "transfer" in the movie "Mission to Mars", where the crew "jumped" from the "MTV" to the a vehicle in Mars orbit. Both are impossible

[nprev]

Well, it actually was just a back-of-the envelope exercise, Jim; it wasn't submitted for consideration or anything like that. He's still fishing for a topic & hadn't heard of the Blue Origin project, so we spent about ten minutes talking about it.

Of course, anything's possible if enough energy is available (admittedly a purely academic assumption). Whether it's affordable, practical, or desirable, aye, there's the rub!

[edstrick]

Landing an Apollo like capsule on rockets is -- of course -- an idiot idea, unless it's a final impact softening like Soyuz does. But for a VTVL vehicle, it's a different story. The vehicle has a much lower mass-per-square-meter of surface (lot of empty tankage), so atmosphere drag will be more effective in slowing it down. It's already got tanks, and rocket engines and vehicle structural support strength enough to be able to sit fuelly fueled for launch. All you need is landing legs, radar, throttleable engines, and fuel. Certainly, a parachute brake system could help. That boils down to design tradeoffs.