Blue Origins, update |
Blue Origins, update |
Jan 4 2007, 02:47 AM
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#1
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Member Group: Members Posts: 163 Joined: 16-March 05 From: Oakville, Ontario, Canada Member No.: 201 |
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Jan 8 2007, 01:03 PM
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#2
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Founder Group: Chairman Posts: 14434 Joined: 8-February 04 Member No.: 1 |
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 |
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Jan 8 2007, 02:55 PM
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#3
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
[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 |
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Jan 8 2007, 04:35 PM
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#4
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Senior Member Group: Members Posts: 2542 Joined: 13-September 05 Member No.: 497 |
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. -------------------- Disclaimer: This post is based on public information only. Any opinions are my own.
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Jan 8 2007, 07:48 PM
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#5
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Senior Member Group: Members Posts: 2922 Joined: 14-February 06 From: Very close to the Pyrénées Mountains (France) Member No.: 682 |
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. -------------------- |
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Jan 8 2007, 10:22 PM
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#6
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Senior Member Group: Members Posts: 2488 Joined: 17-April 05 From: Glasgow, Scotland, UK Member No.: 239 |
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 -------------------- Remember: Time Flies like the wind - but Fruit Flies like bananas!
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