melaus

I thought the Oberth effect was caused by high velocity, not neccesarily higher orbital energy. since kenetic energy is 1/2*M*V^2 a change in velocty at a higher velocity adds more kenetic energy to the system ie. your ship (because velocity is squared). and conservation of energy is maintained because your exhaust loses more kenetic energy at higher velocities. as far as the more engines being worse, its the mass of the engines. you basically have the same stored energy (fuel) so your potential is the same. with 3 engines you burn for 1/3 as long for 3 times the force. which is the same energy. however your acceleration is your force divided by your mass, more engines=more mass. you'll find that this distinction does not exactly hold up in high gravity situations because if you have a thrust/weight ratio of 1.1 (barely enough to lift the ship) you're spending 10/11ths of your energy just fighting gravity. but too much thrust/weight ratio when in an atmosphere will cause the wind resistance to pick up exponentially too. the key is to find the right balance of thrust/weight in the atmosphere, and to have almost no engines when far from gravity (one nuclear is ideal).

I wouldn't use the word lift.. with a thrust/weight ratio of 1 its more like hover. Ideally I think you'd want 1.5-2.0 thrust to weight ratio. but this is eve we're talking about so 1.3 or higher is probably a more realistic goal. any lower than that and you'd be spending almost all your energy fighting gravity and not moving. between the two nukes and the 3 man pod, you're gonna be hurting on thrust/weight ratio and hence... fuel.

On my 3 kerbal mission to eve and back I used a nuke engine from eve to kerbin on the second largest tank. as long as you get high enough out of the atmosphere before you make it to your last stage you should be fine with that. but you only want 1 nuke, any more is just a waste of valuable weight which hurts a lot when you're on eve. and congrats on getting a 2000+ ton ship off kerbin, thats the hardest part.

using them requires more parts to lift the same weight than the big engines and tanks even if they are far more efficient. usually i try to keep the part total low and the complexity as low as possible (not that its possible with a 10k ton asparagus rocket)

Here is mine, the picture notes say it all http://imgur.com/a/Z8GzJ I'm working on a 10k ton ship, but I honest dont think i'll get it to work.

measuring mass and the planet's radius with a larger orbital radius may reduce the magnitude of some of the sources of error due to slightly non-eliptical orbit and your measurement of time. Although I dont imagine the error would be very significant even with a smaller orbit as long as you make the measurements accurately.

I know of three successful flights to eve and back with stock rockets (except for mechjeb). None of them used space planes though. Images below http://imgur.com/a/HHPog http://imgur.com/a/Z8GzJ http://kerbalspaceprogram.com/forum/showthread.php/23491-EVE_M-(madness)-the-first-cpu-friendly-eve-return-design!-(-howto-fly)

congrats SpaceGibsy, I have to be honest, I didn't think that ship design could do it without some adjustments. Landing on eve with chutes isn't about making a powerless landing, its about decreasing the fuel used to land. they also have a diminishing rate of return in terms of using lots to slowing you down even more, so a powerless landing might not even be possible. chutes weight a fraction of a ton, while the fuel used to land usually ends up being far more than that. and yes R_rolo1, you're better off with the nuke engine (even with the weight) than with an aerospike, by the time you're on the last stage, if you're not in space or near space with a good enough velocity, you've probably failed anyway. trust me, i've tried.

Interesting ship. have you figured out if that thing can land on eve? that part looks... deadly.

yeah, its all asparagus, 32 stages in all. I haven't seen anyone break the 2000 ton barrier before. It took a lot of trial and error. at that size even the smallest change would make the difference between flying and exploding on the launchpad.

Thats true, I guess i was assuming it said "stock" somewhere in the challenge, my error, and btw thats one of the coolest space planes I've seen

I accept your challenge and I raise you. 3 kerbal missions to eve and back, all stock except mechjeb. Its possible... barely. http://melaus.imgur.com

I dont think you fully appreciate the exponential nature of gaining more Delta-V. for example to move 100 tons a certain distance you'd need a 200 ton stage, and to move 200 tons, you need a 400 ton stage so each stage gets exponentially larger and gets you less Delta-V from it. to get to every planet and back you'd probably need a ship over 50,000 tons (very low estimate), and the largest I've ever seen is in the lower 2000 tons area.

I hope by "all planets" you dont mean in a single trip. because if they can land on all planets and get back on one voyage they should get -1000 points for cheating.

I believe all units in KSP are metric, I'm guessing its Newtons