The Space Derby is a racing event for unpowered, unmanned miniature space ships. The Space Derby race is an annual event run by Pack 317. With the help of adults, Cub Scouts build their own space ship from kits containing a block of balsa wood, plastic wings, a plastic propeller, and four rubber bands.

Get ready to "blast off" in Fall 2021!

Vehicle Construction

Pack 317 provides an official Space Derby kit to each Cub Scout. The Scout begins with a block of balsa wood, three plastic wings, and four rubber bands. The finished rocket must meet all requirements, as set forth in the Pack 317 Official Space Derby Rules (below).


Blocks can be sanded with sandpaper, sanding block, or a powered sander. Following basic design rules, a Cub Scout is able to design and decorate the car as they choose. Rockets vary from unfinished blocks to whimsical objects, to accurate replicas of actual space ships.

The Race

The Pack 317 Space Derby Race is run on a four-line hand-crafted wood derby track. We use race officials at both ends of the track to administer and officiate the results of the race. The race is run in heats, by den, and overall pack winners.

2021 Cub Scout Pack 317 Official Space Derby Rules

Event Rules & Regulations

  • All rockets must pass the following inspection to qualify for the race:

    1. Only basic materials supplied in the Official BSA kit may be used. The hanging device supplied in the kit must be used.

    2. The rocket body may be no longer than 7 inches, not including the propeller and fins. Width 2.75 inches - Three rubber bands per rocket.

    3. There are no restrictions on the weight of the rocket. The rockets may be detailed in any way as long as it does not exceed length restrictions, is flight worthy, structurally sound and does not interfere with another rocket during the race.

    4. The nose cone (propeller assembly) must not be glued in place on the nose of the rocket.

    5. A notch or groove should be formed in the tail of the rocket to seat the band holding dowel. The band holding dowel must not be glued in place. (These rules allow band replacement in case of breaks)

    6. Scout may use graphite powder between the propeller and the bushing if desired. Other forms of lubrication are prohibited.

    7. Rockets with wet paint will be disqualified

    8. Once the rocket is submitted for entry, no further adjustments can be made except in the case of mechanical failure.

    9. At registration judges will assign a number to the rocket and separate it by Den.

    10. Officials will wind the rocket propeller up to 50 winds then place the rocket into position at the finish line. Upon completion of the race, the race official will give the rocket back to the pilot.

  • The race will broken into several heats:

    • Lions

    • Tigers

    • Wolves

    • Bears

    • Webelos

    • Arrow of Light

    • Overall Pack Champions (1st Place from each den heat)

  • Any entry that experiences a mechanical failure will be allowed to re-race if it can be repaired during the same heat. It will count as a heat loss if it cannot be repaired prior to the beginning of the next heat. All repairs of this type must be done with a race official observing and certifying as to its flight worthiness.

  • The fastest rocket to the finish line is the winner. In the event that all rockets don’t reach the end of track, the one that goes the furthest is declared the winner.

  • The race will be double elimination. A rocket's lane position will be changed between the first and second runs. A rocket must lose twice before it is eliminated.

  • Only the Racing Volunteers will be allowed in the Space Track area

  • One Rocket per Scout

  • All rulings by “Space Command” are FINAL.

Tips & Tricks

  1. The hanger’s rounded end must point forward.

  2. The hanger must not protrude into the rubber-band chamber.

  3. The hanger must be very firmly glued on.

  4. Groove for rear dowel is deep enough so dowel does not twist when rubber motor is wound tight. Do NOT glue the prop nose cone so that rubber bands can be replaced.

  5. Lubricate rubber bands in castor oil or a glycerin/soap mixture if they seem dried out or brittle.

  6. Propeller nose button can be lubricated with graphite.

  7. Fins are accurately aligned so rocket flies straight.

  8. Test the propeller and rubber band strength by winding the propellers clockwise.