Proof of concept Mk 3 SSTO

[Jovus]

I made this craft as a potential learning guide for those who are having trouble using Mk 3 parts to make an SSTO spaceplane in KSP 1.02. She doesn't fly pretty, but she'll get the job done, and bring 16 passengers along for the ride. (Alternatively, you can replace the cabin with a cargo bay.)

Download: http://kerbalx.com/Jovus/Trial-Mk-3-SSTO.craft

To fly to space, hit the staging button for take-off. Leave the runway at around 80m/s, promptly put the gear up and pull into a 30 degree climb. Continue climbing until you get to 10km, then level off until you reach ~ Mach 1. (Probably more like Mach 0.93 or something; don't sweat exactitudes.) Once you get there, climb to ~14km without losing too much speed. Then, enter a ~10 degree dive to punch through the Mach barrier. Once you're going something like Mach 1.4 or 1.5, pull up and begin climbing again. Around 18km, level off and ride the power curve. You'll start to overheat from atmospheric effects; that's fine. Once you hit Mach 3.5 or so, pull up gently until you get to 20km, then ride the air level until your airbreathers die down to around 400kN of thrust. (You do have a thrust readout, right?) Finally, switch to rockets by pressing 1 (which also toggles the air intakes) and pull up sharply to get above the drag. Level out once your Ap is around 45 or 50 for a more efficient right to orbit.

WARNING: this is intended as a proof of concept, not as a workhorse. In order to become a truly useful spaceplane, it needs some modifications, such as solar panels, and probably a little tweaking of the flight surface placement to aid stability. It is my hope that if you're having trouble using Mk 3 parts for SSTO spaceplanes, this design will offer you a starting point for getting it right.

[Chris_2]

Nice no-nonsense SSTO. You could try to reduce drag as much as possible to allow crossing the sound barrier without performing a dive. Maybe remove the canards, some of the air-intakes (those have a lot of drag and are usually not worth it in 1.02) and maybe use smaller wheels? Maybe that'll reduce drag enough...

[Jovus]

Nice no-nonsense SSTO. You could try to reduce drag as much as possible to allow crossing the sound barrier without performing a dive. Maybe remove the canards, some of the air-intakes (those have a lot of drag and are usually not worth it in 1.02) and maybe use smaller wheels? Maybe that'll reduce drag enough...

Hey, thanks for the feedback!

I wouldn't be surprised at all if there were many ways to optimize this to work much better. For one thing, there's going to be an LFO imbalance for most flight paths. For another, you're right about the intakes and possibly the wheels. I just threw this together in about 45 minutes to see if it could be done after seeing that people were having trouble with it, and thought I'd show the fruits of my labor in case it helps anyone.

If I were making this thing serious, I'd probably also put a smidge of dihedral on the wings. It tends to show a bit of corkscrew instability at high altitudes.

As for the canards, I think even in an optimized design I'd keep them. For one, they add some pitch authority, and I'm not comfortable just leaving that to the horizontal stabilizer on a beast this big. For another, they make it look like it has eyebrows. Everything needs a small touch of flair when it can get away with it, no?