04-12-2014, 02:37 PM | #11 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Spaceships] Winged Spaceships
Spaceships more than makes up for that by ignoring tank mass and atmospheric performance reduction (the SSME has roughly a 20% loss in performance at sea level). In addition, mps should actually be ISp/3,280.
Last edited by Anthony; 04-12-2014 at 03:15 PM. |
04-12-2014, 03:00 PM | #12 |
Night Watchman
Join Date: Oct 2010
Location: Cambridge, UK
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Re: [Spaceships] Winged Spaceships
Got a source for that? I like wacky Cold War projects.
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04-12-2014, 03:08 PM | #13 |
Join Date: Mar 2013
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Re: [Spaceships] Winged Spaceships
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04-12-2014, 03:39 PM | #14 |
Computer Scientist
Join Date: Aug 2004
Location: Dallas, Texas
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Re: [Spaceships] Winged Spaceships
All I can find is the TU-119, which had some kind of heat-driven turboprops with heat supplied by an onboard reactor, which couldn't have been too critical on weight because several of the test flights were made with the reactor in shutdown.
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04-12-2014, 03:57 PM | #15 |
Join Date: Aug 2004
Location: Alameda, CA
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Re: [Spaceships] Winged Spaceships
I know about a test in the USA involving a B-36. The reactor wasn't used to power the aircraft. Just tests to see if a reactor can be carried. The project was canceled due to fears of a crash.
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04-12-2014, 04:10 PM | #16 |
Join Date: Mar 2013
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Re: [Spaceships] Winged Spaceships
From what I understand the problem comes from trying to use the reactor to power the engines. Basically you can build a plane that has enough lift to carry a reactor, you can't build a reactor that can generate enough power to make the plane fly
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04-12-2014, 04:12 PM | #17 | |
Join Date: Jul 2005
Location: Jeffersonville, Ind.
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Re: [Spaceships] Winged Spaceships
NASA had a functioning nuclear rocket (not a ram-rocket mind you) in testing for years that had good performance, but required too much maintenance and required too much enriched radioactives to be a serious contender for spaceflight. At the end of the project they pulled the control rods out and caused it to explode, which ****** the Soviets off because of test ban treaties.
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04-12-2014, 05:36 PM | #18 |
Join Date: Mar 2013
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Re: [Spaceships] Winged Spaceships
Ok, the reason I asked this question is that I'm working on creating stats for something like the Dassault Aerospace Transporter. For those of you who don't know what that is (Likely most of you) that was something a bit like the Concorde but with both jet and rocket engine, the jet engines would have accelerated it to Mach 2 before the rocket engines took over accelerating it to Mach 4. At that point a separate orbiter, a bit like the Space Shuttle, would separate from it a la the Short-Mayo Composite which then ascends to orbit.
Problems with this is that the booster stage needs to be separately streamlined, and the need for both jet and rocket engines, both of these cut into the fuel percentage, I'm only getting 10 fuel tanks for a measly 2.1 mps out of the tanks using standard values. And it really should have streamlining on the airframe level from Interstellar Wars (Which would help, a single jet engine and fuel tank would provide a staggering 1.32 mps) |
04-12-2014, 06:20 PM | #19 |
Join Date: Feb 2005
Location: Berkeley, CA
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Re: [Spaceships] Winged Spaceships
Well, that's not a problem with the performance rules, it's entirely realistic that you need a fuel fraction of 85-90% to get into orbit. That's a significant factor in why things like the device you're describing have never been built -- they simply can't be built without exotic materials or exotic propellants.
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04-12-2014, 06:41 PM | #20 |
Join Date: Mar 2013
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Re: [Spaceships] Winged Spaceships
From what I understand Jet engines are supposed to help in cases like this, while jet engines weigh more then rocket engines they don't need oxidant. It also avoids the problem poorer performance close to sea levels of rockets, which means you might be able to get away with lower thrust but high ISp designs.
If I switch to a X15-B inspired design things get a little better, but part of my problem is that one of the worlds I'm working with has a higher escape velocity then Earth |
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