Nairou

Thanks all! Your replies have been extremely helpful! I've now got several promising articles to read. You guys rock!

Thanks, that part makes sense. The thing that doesn't make sense is when people talk about engine parts as having high or low delta-v. Like, the ion engine. Very low thrust, but I've heard repeatedly that it has a high delta-v. I know it has a very high specific impulse, but I would have thought that it had a very low delta-v, given the low thrust. But then, I keep thinking in terms of thrust. If an engine has high thrust, I assume it has high delta-v since it can increase velocity more quickly. Somewhere in here I'm sure my assumptions are incorrect...

Thanks for the awesome replies and links! I didn't realize there was so much technical information in the wiki. Two remaining questions: - As far as calculating the mass of a rocket, which everyone refers to, I assume the only way to do that (without using mods) is to go through each component you use, look up it's mass in the parts listing, and add them up? - Everyone talks about deltaV, and the wiki mentions that it is a change in velocity. That doesn't quite explain what it is or why it's important. What exactly does a high deltaV represent? A rocket that can increase it's speed very quickly? Is that just another representation of thrust? Why do some tasks require a higher deltaV than others?

The two biggest problems I have when building spacecraft are getting it off the launch pad (too heavy, not enough thrust), and running out of fuel (usually before achieving orbit, but sometimes later in more complex missions). I've launched many successful rockets, but it's usually just trial and error after several failed attempts. I've watched videos of people doing really fancy missions with equally fancy rockets, and they never have these problems... How do you calculate how much thrust or fuel you will need for a given spacecraft? I can only assume that's what people are doing, but I don't know where they get the necessary information to make those calculations...