SoberSquid

Excellent resources. Yeah, the math definitely isn't for everyone. I don't often do the math by hand, other than workplace doodles. Mostly I use Kerbal Engineer to figure out Delta-V levels when building, and rough estimate charts like this guy when playing. I just wanted to outline how the math works out for people who wanted to know

Breaking this down a bit more for any kerbalnauts that want to do this by hand for fun and profit. Hopefully my math isn't off here, if it is, feel free to correct me! For anyone who doesn't know what a logarithm is, it calculates out "How many times (x) do we multiply y to get number z" (log ^ y (z) = x) , for example, 5 * 5 * 5 = 125, so log^5(125)=3. For the rocket equation, we are looking at a natural logarithm, which uses Euler's Number (2.71828) as Y. So ln is the same as saying log^2.71828, or log^e. So lets break down the rocket equation based on the information in the OP The rocket equation when using Isp is DeltaV=Isp*g0*ln(M0/M1), where g0 = Gravity (9.81m/s^2), M0 is mass when full of fuel, and M1 is empty weight. So pulling down from above, we have an approximate empty weight of 12.8 (Fuel units weigh about 0.0111 each, so 46.1-(0.0111*3000)) DeltaV=800*9.81*ln(46.1/12.8) DeltaV=7848*ln(3.6015625) DeltaV=7848*1.325 DeltaV=10398.6 So you should have plenty of DeltaV for things, assuming you have a way to get all that into space directly. The harder part of those engines is they are pretty bad in Atmosphere by comparison (Having an Isp of 280 instead of 800 in atmosphere, plugging that into the equation you come out to 3639.51, on those engines alone, you won't even get into orbit from the surface! For TWR you are looking at TWR=Thrust/(m0*g), so in this case, TWR on Kerbin would be 120/(46.1*9.81), or 0.265, whereas in space it would be 2.603 (120/46.1). As such, I would expect your ship to work quite well in space with those engines, but on Kerbin, It wouldn't lift off by itself. Taking that ship, strapping it to a rocket and getting it to space first is your best bet. Once in space, the ship should easily be able to make it to the mun and back.