GoSlash27

There is no limiting factor that keeps my SSTOs from achieving orbit, but there is a size limit to how big I build them. They can be a PITA to land when they're too large due to the slow handling response. Best, -Slashy

The Mun landing was faked!

Val, Yeah, I understood that from your OP, but I'm just correcting the oversight. All other things being equal, the location of the CoL relative the CoM *does* matter for dynamic stability, regardless of what the pressure center is doing. I need to differentiate between static stability and dynamic stability as I'm using the terms. Dynamic stability is the tendency to resist disturbances and actively seek a stable state. Static stability is the tendency to fly straight and level with no trim adjustments or control inputs. What you're talking about by my definition is static stability, and yes... the pressure center is what's important here. But for dynamic stability in pitch, you want the CoL behind the CoM. It doesn't have to be far behind it, but it does need to be behind it. Otherwise it will amplify disturbances in pitch rather than damping them. Best, -Slashy

One caveat: The center of lift actually does directly contribute to/ detract from the longitudinal stability. As lift is increased, it creates a pitch moment about the CoG. Having the lift ahead of the CoG will result in an aircraft that is dynamically unstable with pitch; increasing AoA generates more lift, which creates a nose- up pitch moment, which creates more AoA. Having the lift behind the CoG has the opposite effect, creating dynamic stability. An excess of this stability is what causes lawn- darting. For me, the key to stable and controllable aircraft isn't so much the longitudinal position of the CoG, but rather ensuring that it stays put as the fuel drains. This means fuel tanks directly at the CoG. Best, -Slashy

Okay, Disco that doesn't suck: ^ This is more of a funky roller- disco. Best, -Slashy

I didn't see anybody mention this, so I'll put it out there: The Moon is tidally locked to Earth. There is therefore no synchronous orbit within it's sphere of influence, so a lunar elevator is impossible. Best, -Slashy

I use it in early career when it's the only game in town. Better than sending a manned mission for science flybys. Once I unlock a better probe core, it gets relegated to the trash heap. Best, -Slashy

What an odd request!

My rules of thumb: 1 jet per 5-10t of payload. This should work out to about 1 jet per 20-40t of spaceplane. 400 units jet fuel per engine. 1 unit of lift surface per side per 5 tonnes of spaceplane. There's a lot of leeway here. .001m2 *effective* intake area per engine. I recommend the precooler (1 per engine), but the surface mount variable ramp is good also (2 per engine). Rocket fuel varies with type of air breathing engine. 2 Terriers per jet engine or 1 Poodle per pair of jets. Rockets should be vacuum engines. Wings should have enough incidence to give zero angle of attack (prograde marker aligned with nose) at Mach 1. Generally speaking, you can expect about 4t of total spaceplane per t of payload (varies with engine type). Most importantly: Design for minimal drag instead of high thrust. You can make crazy- efficient SSTO spaceplanes that just barely break Mach 1.6 in level flight. The less of your total mass is engines, the more you can dedicate to payload. Best, -Slashy

ihtoit, Is staging (with that amount of fuel) allowed, or must it be a SSTO?

I collect them and use them from time to time. They're pretty handy for some types of calculations. Best, -Slashy

You could expose the trash to vacuum, which would freeze-dry it and kill all the microbes. I bet that would be a fine way to wash clothes in space. Best, -Slashy

veeltch, I'm talking about integrating orbital telescopes like Hubble, Kepler, etc. into KSP for science and expanding the in- game database. Best, -Slashy

awbeck, No worries. If you get to the point where you think you can do it and want to give it a go, hit me up. Best, -Slashy

I would really love to have someone who's fluent in Matlab to create an online version of my stage design spreadsheet. Basically it does the DV calculation backwards for every engine. You plug in the mass of your payload, DV requirement, minimum acceleration, reference body, and % atmospheric density. It spits out how many tanks you need, how many engines, total mass, and total cost for all engines. This allows you to see at a glance which engine you should use for a stage, as well as exactly how to build it. ^ Example screenshot. If you're interested in tackling this, I'd be more than happy to walk you through how the math works. Best, -Slashy

Well again, congratulations and best of luck to you! -Slashy

Congratulations! So if I may ask (and feel free to tell me I may not), what's the plan? Best, -Slashy

But OTOH you can use a rail gun on the lunar surface to propel payloads into an orbital Hohmann transfer for essentially nothing, with a tiny kick at apoapsis to circularize. Cheaper in the long run. Best, -Slashy

I limited my thrust, but not my speed (if that makes any sense). I throttled back my stage 2 SRBs in order to extend their burn time. That may have limited my design's efficiency... I tried to get mine to "float" around 45 km without excessive cosine losses until apoapsis was established. This yielded my best efficiency, but I clearly left some on the table since I don't have MJ. I agree with your findings; using upper stages in parallel is a definite no-no at least until their Isp matches that of the SRBs. I tried a Poodle cluster both ways, and the series lifter was far cheaper (though not cheap enough to bother submitting here). Best, -Slashy

Starhawk, True, but comparing apples to apples, the "Mercury" needs very little ablator (technically none in KSP) while the "Apollo" needs more for a Munar reentry. This makes the disparity worse. As do I. That's why I use hitch hiker cans. But as it sits now... I just never use the multi- crew pods because they're so far out of balance. Happy Super Bowl Day! -Slashy

sal, I'd be inclined to agree with that... if the Mk1-2 was actually more advanced than the Mk.1. When you throw in the 'chute and heat shield (plus a docking port for the "Apollo CM"), the weights are, respectively, 1.2 tonnes vs. 5.9 tonnes. Best, -Slashy

Dearest enfezzed one, Me thinks you may have forgotten a crucial step Best, -Slashy

Sovek, I was conducting my tests in stock. .3m gave me about 15° of pitch. This does raise another potential problem; it apparently doesn't behave the same way in stock as it does in FAR. Also, no doubt, it won't behave the same way with a heat shield as it does without, or with changes to the 'chutes. Best, -Slashy

Whoa! O_O

Waxing_Kibbous, As the old saying goes, "It's your world, Squirrel" Best, -Slashy