Oh. My. Gosh. I nearly cried, that Starling flew so well! I vainly attempted building my own SSTO for ages. The KR-X Sparrow from Zombiephylax seemed to be my best hope, but I could never reach orbit with enough fuel to 120km for timewarping... I nearly gave up completely. Until Now! Kicking the NERVAs in at 2/3rds throttle does the trick - right through the 'danger zone' above 25,000km. I could probably milk the jet to get me to 30,000kms but that's really jumpy on the throttle, and then I would end up losing altitude before gaining enough speed (that was always my problem in the Sparrow). Good sir, I salute thee!