You will need enough hoagie buns for each child to have one, mayo, mustard, relish, sliced cheese, various lunch meats, olives, carrot sticks, celery sticks, broccoli and cauliflower, tomatoes and lettuce, large pretzel sticks.
Have each child make a hoagie sandwich and then allow them to use the other items to turn their sandwich into a rocket ship or other space vehicle.
References / Source:
GSLC Pow Wow 2005