Knyght Posted May 29, 2012 Share Posted May 29, 2012 I\'ve attached what I have so far. This is much better than my first attempt but seems to have its own set of problems.So I really like the idea I have here, but the execution is proving problematic. The idea is that the fuselage of the shuttle is made from fuel tanks, and these feed the engine below. Any fuel not used on mission can be burned off before/during re-entry, then the engine detached. With the dry tanks the glider should be fairly light and (hopefully) controllable.Observations and problems:1. I seem to have plenty enough thrust and fuel to get to orbit. This isn\'t a problem.2. Massive problem 1: It\'s stable enough (with ASAS) to go up just fine. But something is making it flip if you so much as try to turn slightly to get to orbit. I\'m thinking it\'s either the wings or the top-heavy nature of the craft. Can fix by lowering thrust quite a lot while turning but this presumably mess up orbiting attempts and is terribly inefficient anyway.3. Massive problem 2: Since the engine is made to drop off along with unnecessary RCS/RCS fuel/ASAS the fuel doesn\'t flow, and since the engine is direcly below, I can\'t seem to get a direct line of sight for the fuel duct. This is annoying. Can I reroute the fuel through say, the wings? I don\'t want to move the tanks because they are the crux of what makes this design pretty neat.4. Maybe the best idea is to use less RCS thrusters (there are so many from when the craft was so unstable that it needed them just to remain stable), swap the ASAS for a SAS and put an ASAS between the coupler and tricoupler and put the engine directly underneath the fuel tanks. I don\'t really like this idea since I\'d probably need bigger wings and thus more thrust and more stability tinkering. Also that is the boring way out.5. It\'s still pretty unstable, even with all those struts.6. Maybe I should move the wings forward a bit? dunno. Can\'t test the glider until I can get the fuel out of the tanks anyway.So I would like some suggestions from my fellow engineers. Link to comment Share on other sites More sharing options...
Knyght Posted May 29, 2012 Author Share Posted May 29, 2012 Oh, woops. apparently you can re-route fuel through the wings. Awesome. Now just the stability! Link to comment Share on other sites More sharing options...
sal_vager Posted May 29, 2012 Share Posted May 29, 2012 I think I can help with problem 1, the wings are grabbing air when you turn, try keeping the shuttle sideways and pitch over more gently, with the main wings unable to grip the air it should reduce the tendency to fall over, at least that\'s how I manage it.You could also try adding wings to the bottom, they will grab air and try to keep you vertical, it\'s not a cure but it can help. Link to comment Share on other sites More sharing options...
Endeavour Posted May 29, 2012 Share Posted May 29, 2012 I don\'t think you need an ASAS because you have the nose cone version of it. Link to comment Share on other sites More sharing options...
Knyght Posted May 29, 2012 Author Share Posted May 29, 2012 I thought the avionics package worked differently from regular ASAS? Like, it doesn\'t keep you pointed in the same direction or so. Link to comment Share on other sites More sharing options...
sal_vager Posted May 29, 2012 Share Posted May 29, 2012 That\'s true, the Avionics package is like the ASAS but it does not prevent you from steering, and it can drift, though not very fast.The ASAS can hold you rock solid if you have enough SAS, wings and gimballed engines for the ASAS to control, but every craft I have made similar to yours has also had so much force tipping it over that ASAS cannot stop it.Also you could test your shuttle if you launch it without the rocket, just take the rocket off, rename it 'shuttle test' or similar, and save the craft, you\'ll still have the complete shuttle and launcher under its original name.I\'ll send you my old 0.14.4 design, it\'ll work in 0.15 and it might help you, it can get to orbit, thrust about a bit for orbital rendezvous, de-orbit and glide, it cant land though unless you put wheels on it, but they made it look strange to me. Link to comment Share on other sites More sharing options...
Endeavour Posted May 30, 2012 Share Posted May 30, 2012 Every shuttle I have that works has the rockets around the plane, not under it. Link to comment Share on other sites More sharing options...
togfox Posted May 30, 2012 Share Posted May 30, 2012 2. Massive problem 1: It\'s stable enough (with ASAS) to go up just fine. But something is making it flip if you so much as try to turn slightly to get to orbit. I\'m thinking it\'s either the wings or the top-heavy nature of the craft. Can fix by lowering thrust quite a lot while turning but this presumably mess up orbiting attempts and is terribly inefficient anyway.Rotate your craft in the VAB by 90 degrees. This means you\'ll ascend the same way, but when you do your gravity turn the turn profile has changed as the wings are now playing a different role in the gravity turn. It took me a little bit to understand the wings of the shuttle were affect the craft as a whole despite being under power from below. Your shuttle is more than a passenger - until it disengages it physically is a part of the lifter and the wings/surface area needs to be respected. Link to comment Share on other sites More sharing options...
StellarUniverse Posted May 30, 2012 Share Posted May 30, 2012 However, you need some skill to get to Mun. I have did it once. Also, 16/0=? should be found for ?x0=16. That means divide by zero is undefined. Link to comment Share on other sites More sharing options...
Knyght Posted May 30, 2012 Author Share Posted May 30, 2012 Yeah I remade it and built it outwards rather than vertically (easy fix I figured) and all is fine now <3And I already rotated it 90deg, figured that out pretty early.And I\'ve been to the Mun and back. Actually found that relatively easy. The hard part is landing.But all is well. Thanks. Link to comment Share on other sites More sharing options...
s3f Posted May 30, 2012 Share Posted May 30, 2012 i just tested you design, ascent was really nice but needs moar boosters neither over- now underpowered. but you staging is somewhat flawed the shuttle\'s engine didnt fire and got seperated. it\'s too late now but if you want i could try and improve your design. been working on some shuttle designs huge explosions on the launchpad myself lately Link to comment Share on other sites More sharing options...
Twinky827 Posted May 30, 2012 Share Posted May 30, 2012 That\'s not a shuttle, thats a plane ontop of a rocket... At least I actually make it look like the REAL shuttle Link to comment Share on other sites More sharing options...
Endeavour Posted May 31, 2012 Share Posted May 31, 2012 That\'s not a shuttle, thats a plane ontop of a rocket... At least I actually make it look like the REAL shuttleIs it asymmetric? I must see it if it is. Link to comment Share on other sites More sharing options...
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