I just wanted to see if others had the same issue, because I cannot reproduce this thing. Or at least I don’t see want can trigger it. And it will not happen when I focus the view on the vessel. So I can easily done multiple small burst to control the descent and all goes well. But on this specific attempt it changed, I can’t tell if it was in the middle of a burst, or in between two bursts. Yes I view the ISP by right clicking on the engine. It’s a really simple design, no fancy things here. Reactor, one Fuel tank, 2x hitchhiker (it was for a station in orbit contract of 9 kerbonauts), little can for the pilot, batteries, solar panels and mech jeb. Not even any landing gear. But landing on the greater flat on the engine is not so much of a big deal on Minmus, so I give it a try to collect ground samples, EVA and crew report. (and I landed it without any other problem that the one described here). Yes MechJeb is up-to-date for 0.90 and the career was started in 0.90 No Fuel line. I can, later today, attach the craft file, but again it didn’t seem to be specifically attached to this craft. (or at least it’s not my impression) Thanks NASA Hire me, yes I wish NASA can hire me too