There are many alternative non-rocket designs such as: cruise missiles, boats (Titanic is always popular), planes, jets, etc. The little plastic straw MUST go over the hook (not just the shaft as the drawing in the space derby kit illustrates) This is where the rubber bands will hook on - the wire hook will cut the rubber bands without the plastic straw liner!!! Lubricate the rubber bands (spray silicon, ethylene glycol, castor oil, ...)! Stretch them numerous times before loading, hand wind the bands numerous times before races (20 winds, then 40 winds, then 60, 80, 100) -- this helps relax the elastic properties of the band and makes it more pliable and durable (this is exactly why the clowns stretch the balloons before blowing them up!). The plastic dowel at the rear of the space derby to hold the rubber bands MUST be kept from rotating (groove out the back so the dowel can sit in it!) - do not glue it! Do not glue the front nose/propeller assembly into the front of the space derby. It is pulled off to re-load new rubber bands! Do not glue the back dowel onto the rocket. It is pulled off to re-load new rubber bands! The propeller should have the rounded shaft-end pointing into (touching) the space derby (this makes the bending of the wire easier and it reduces friction). Use 3 rubber bands together.

Make Sure The Propeller Is On Correctly.
Several Space vehicles this year had the propellers on backwards. When looking at the hub (center) of the propeller closely, there will be rounded end and a rougher end that is not even. The rounded end goes towards the rocket ship and should be touching the small metal bushing. The rougher end has a little protrusion that is designed to catch the wire when it is bent over. Which leads to the next tip...

Don't Cut The Bent Over Wire Too Short.
We were guilty of this one. In the attempt to be neat I cut it too short and then during the winding, the propeller can slip and spin around. Leave a little more than you think is necessary and you should be fine. Just bend it over to form an inverted 'U', with plenty to grab the prop, and then there should be no trouble.
by Ron Alley