[MikeDubreuil]

I think a lot of teams use the trips as a reward for time put towards the robot. Keep track of how many hours each student participates during the 6 weeks. Explain that only X amount of students can go, lie if you have to. Give "double time" for time spent at mandatory meetings, if someone doesn't show up for a mandatory meeting a familly member should have died or they get time taken away from their total.

People who are all about FIRST don't need the trip as a prize to know why they should put a lot of time into FIRST. However, newbies usually need to experience the first year before they decide to throw tons of their time at it.