kUSer

Thanks guys.

So my dry mass is basically my FullMass - WeightOfFuel?

I have been struggling a little recently with KSP. When I do the math my landers have about 5000 Dv, but I tend to run out of fuel way half way back home or even before I have even landed on the surface. After a lot of trials and fails I narrowed my problem down to two things: 1) I am calculating my dry mass wrong and thus think I have more Dv than I actually have. 2) My version of the game is seriously bugged. The way I always calculate my dry mass of a craft is I just remove the stage and the have the new mass of the craft. E.G: A craft consisting of these parts: Stage 2: 1 x Command Pod Mk1 Stage 1: 1 x TR-18A Stack Decoupler 1 x FL-T800 Fuel Tank 1 x LV-T45 "Swivel" Liquid Fuel Engine This ship has a full mass of 6.89 tons. With the TR - 18A Stack Decoupler, FL-T800 Fuel Tank and LV-T45 "Swivel" Liquid Fuel Engine removed it has a dry mass of: 0.89 tons. We also have an Isp of 320 in a vacuum. Using the Dv formula: dv = ln(FullMass/DryMass) * Isp * 9.81 we get that our Dv is about 6 424.702, that's plenty to get to the moon and back (if already in a stable 70 KM orbit around Kerbin). This ship only gets to surface and not back. So what am I doing wrong?

Thanks guys.

I am currently using this algorithm to calculate the total delta v my rocket has: dV = ln(Mstart / Mend) x ISp x 9.81. I have a couple of questions though. Do I need to multiply every time with 9.81 (Kerbin's gravity) or should I multiply with the gravity of the area that I'm in, e.g. on Minmus it would be: dV = ln(Mstart / Mend) x ISp x 0.481, but this would cause a problem if I am in space, as multiplying with 0 (for the gravity) always = 0 Is there a better algorithm for this or am I just confused? Thanks.

Since the new update 1.0 I am finding that the old delta v map is not working anymore since the physics changed. I was wondering does any one know of an up to date delta v map, or how one can calculate how much delta v it would take to get to each planet? Thanks.