Hi guys. I set myself a goal to design a SSTO space plane capable of carrying small payloads to LKO. I've set some restrictions; it must use the Mk3 shuttle cockpit and Mk3 fuselages (because using parts with wonky centres of mass is fun!) and it will not use nuclear engines. After a few weeks of on-and-off tinkering and scrapping four previous prototypes, I've finally got something that works. The Hauler Mk. 5 does get into orbit with a lot of brute force and very little gracefulness, with a mass of 50t at launch, 6 turbojets, 92(!) air intakes, 2 aerospike rockets and loads of fuel. It has all the power and fuel to get into orbit and beyond, but it's a nightmare for me to pilot. The craft is really unstable travelling at supersonic speeds at altitudes of about 25k. SAS is not reliable under those conditions; any attempts made to correct rolling ends up with the whole thing slowly resonating into catastrophe. I have FAR, Chatterer, Procedural wings, Procedural fairings and the Kethane mod installed in my game. What changes should be made to this design to improve its handling at high speeds and altitude? What settings could I tweak in the FAR light Assistance to make this thing fly straight? Pics here: Plan view Side view And if you want to fly this nightmare: Hauler 5 craft file I know this thing currently has way too much jet fuel and the RCS needs tweaking, but I'm outta ideas when it comes to aerodynamics. Help?