Spaceplane Design & SSTOs

Learn how to design effective spaceplanes and Single Stage To Orbit (SSTO) vehicles in Kerbal Space Program. We'll cover essential parts like the CR-7 R.A.P.I.E.R. engine and key design principles.

Alright, let's talk about building spaceplanes and those awesome Single Stage To Orbit (SSTO) craft! These can be a bit tricky, but once you get the hang of them, they're incredibly rewarding. We're going to focus on a key component that makes many of these designs possible: the CR-7 R.A.P.I.E.R. engine. ### CR-7 R.A.P.I.E.R. Engine This engine is a real workhorse. It's a hybrid that can switch between two modes: air-breathing and closed cycle. Think of it as having two engines in one! * Air-Breathing Mode: In this mode, the R.A.P.I.E.R. uses both onboard methane and air it sucks in from the atmosphere. This is super efficient for gaining altitude when you're flying through the denser parts of Kerbin's atmosphere. It's like a jet engine, but with a rocket's potential! * Closed Cycle Mode: Once you're too high for the engine to breathe air, or when you need maximum thrust, it switches to this mode. Here, it uses onboard methane and oxidizer (Methalox) to operate like a traditional rocket engine. This is what you'll rely on for reaching orbit and beyond. Why is this great for spaceplanes and SSTOs? Because you can use the cheap, air-breathing ascent to get a significant portion of the way to orbit, saving you a ton of fuel. Then, you switch to closed cycle mode to finish the job without needing a separate rocket stage. It's a game-changer for efficiency! Keep in mind: The R.A.P.I.E.R. has a relatively low Isp (specific impulse) as a jet engine, but its closed-cycle Isp is decent. Its thrust is pretty average in both modes. The real magic is its versatility. This engine is a recurring part from KSP 1, and for good reason. It's a marvel of technology, popular for spaceplane designs, and profitable for manufacturers like C7 and Rockomax. Getting comfortable with the R.A.P.I.E.R. is a big step towards mastering spaceplane and SSTO construction in Kerbal Space Program.