I've already completed 5 missions but now I have another mission that I can't complete because I don't understand, I've done several tests and I'm not understanding the mission well, the mission is:
Test swivel fuel engine LV-T 45 in a sub-orbital path over kerbin and I have to reach a height between 150,000 to 160,000
well, I know how to fly in sub-orbital and I managed to get to that height that is necessary for the mission, I installed this engine in my rocket, I completed all the tasks in that mission but when the rocket reaches the maximum height and starts to descend when down the 150,000 meters a part of the mission is disabled because the test must be done between 150,000 and 160,000, I don't understand this mission, I even installed two swivel LV-T 45 engines, one to take the rocket up to 150,000 and then use the second engine at that time, but the mission is still not complete, does anyone know how to do this mission?