I have additional details on this, I launched 2 experiments to my orbital station using a spaceplane and none of them triggered the "Launch new Experiment" check. I had one of the 2 experiments checked with "Complete in orbit around Kerbin" but when I tried to de-orbit it the contract was not completed and it was reset instead (no green checks at all). I did a bit of digging around and this is what I found: * I tried lifting a the same experiment setup using a rocket and it triggered the "Launch new Experiment" check normally. * Then I tried to launch a rocket powered craft from the launchpad and it worked again. * Then I tried to launch a simple jet-engine powered craft and it worked again. * I tried re-launching my original setup with the huge spaceplane and it didn't work..just like when I launched it originally. At this point I suspected the culprits were the docking ports: my spaceplane has the experiment attached to an orbital module using small docking ports, which in turn is attached to the spaceplane using the large docking ports. So I * launched many small space planes with both rockets and jet engines with the experiments attached to a small docking port but this kind of simple setup always worked well. * launched many more complex spaceplanes up until the point I almost replicated my original setup using only stock parts: my contraptions always triggered the "Launch new Experiment" without any problem (aarg!) * As I advanced through the recreation, at some point I created action groups to turn on the engines instead of hitting the spacebar. Turns out this is the problem: you need to use the spacebar when launching. After that I tried many crafts, jet powered, rocket powered, all of them worked when using the spacebar and none of them worked when activating the engine through action groups or manual "click to activate" (from both the runway and the launchpad) I was pretty bummed that I had to re-launch my experiments but then it dawned on me: I returned to my station, created 1 empty stage, pressed my spacebar and bam! The experiment is now launched I'll return it to Kerbin tomorrow. I hope this helps! P.S. The addon is awesome, keep going with the good work