Jim Jarvis launched his 3 stage rocket ThreeCarbYen to 175,000ft at the recent Balls 2018 launch event. N5800 to N1560 to M1401, very impressive and it was all recovered!
Video Caption: This three-stage flight was performed by Jim Jarvis (with lots of help) at Balls 27 on September 21, 2018. The launch was help at the Black Rock Desert in Nevada. The flight reached about 175,000 feet.