kirbo

Gentlemen! Thank you so much for you answers! I've got it worked out now. Many thanks!

Ah! Great info! Thanks! But when I do my delta/V equations, I plugged in the proper μ for Kerbin of 3530.461 I found on the wiki, and it seems like the delta/V is still too high. Any advice?

So I've got a scenario in which I have a craft in a stable orbit around Kerbin at near as makes no difference 100km. I want to raise the orbit from 100km to 600km, and I want to be able to calculate the delta/V for both burns of the Hohmann transfer. I know the equations are and for the second, where μ is the gravitational parameter of Kerbin, which the wiki states is 3530.461m/s, r1 is the starting radius, and r2 is the ending radius. So if I plug this in, I get v1=sq(3530.461/100)*sq((2*600)/(100+600) - 1. First step, v1=sq(35.3046) * sq(1200/700)-1 Second step, v1= 5.9417* (1.3092 - 1) Third step, v1= 5.9417*.3092 Fourth step, v1= 1.837km/s Now if I convert that to m/s by multiplying by 1000, I get v1=1837m/s. For the second formula, I can plug in to get v2= sq(3530.461/600)*(1-sq((2*100)/(100+600))) First step, v2=sq(5.8841*(1-sq((200/700)) Second step, v2=sq(5.8847*(1-sq(.2857)) Third step, v2=2.4257(1-.5345) Fourth step, v2= 2.4257*.4655 so v2=1.128km/s or 1128m/s. So, if I add v1 and v2, if will give me the total delta/V for the Hohmann, but when I add them up, I'm left with a delta v of 2965m/s, which sounds waaaaay, waaaaaaay to high if I'm just trying to go from 100km to 650km. What am I doing wrong? I'm thinking maybe it's because I'm using the wrong μ. I know that μ = GM, with g being the gravitational constant and M being the mass of the planet. So, if the constant of gravity at Kerbin's surface is 9.81, perhaps I should send a probe up to 100,000m and re-measure the gravitational constant so that I can recalculate the new, lower μ and get a more accurate delta/V equations? Thanks! Kirbo