The Dr Zooch space shuttle had a much better launch on a C6-3 than on a B6-4. On a C6-5 the ejection happened too late and the rocket broke apart. The Odd'l Rockets Cyclone rocket mapleseed worked every time I launched it, and I lost the AS-203 Saturn 1B later that day on a C engine. Watch in full screen 720p to get a good view of the rockets and orbiter.