940 Weekends

How To Build A Stomp Rocket With An Educator From NASA’s Jet Propulsion Lab

For more advice on fun stuff to do with your kids, from ridiculously overqualified experts, check out the rest of our 940 Weekends.

Before you get your kids pumped about spending their retirement years on Mars, you need to explain how they’re going to get there. Enter Ota Lutz, an educator with NASA’s Jet Propulsion Laboratory, who never needs to use the phrase, “It’s not rocket science.” Lutz says that the first step to getting kids to understand rocketry is to understand the principles behind it.

While you could spend hours crafting one of those firework-propelled models that provide seconds of fun, how about a rocket that teaches the same thing and it’s reuseable. Lutz says the easiest way to get young kids into rocketry is building stomp rockets. That’s a sub-$5, sub one-hour project, which, according to Lutz, even impresses astronauts who have been in the real thing. How do you get a spacecraft made of paper, PVC pipe, and a 2-liter bottle to fly more than 100 feet in the air? To infinity, and beyond:

Hit Up The Hardware Store

If you happen to have a bunch of half-inch PVC pipe laying around, this step might be unnecessary. If you relish any excuse to go to Home Depot (Parking lot hot dogs! Power tool demonstrations!), here’s one more. Take this detailed materials list with you, which includes the diagram for the launcher. Here’s the quick reference guide to what you’ll need:

Stuff you have at home:

  • 2 sheets of 8.5 x 11-inch construction paper (printer paper works, too, just don’t use newsprint).
  • masking tape
  • Duct tape
  • A 2-liter plastic bottle. It’s a good idea to have one or 2 extra because eventually they’ll fail. And NASA scientists don’t like when things fail.

How To Put Everything Together

For The Launcher: The PVC pipes fit together without any glue or tape, except for the duct tape needed to fix the mouth of the plastic bottle to the pipe. That’s going to be where you kid jumps on it and creates an air explosion out of the bottle. Once you have your pieces, constructing the launcher will take about a minute.

For The Rocket:

  • First, bust out your paper. This is going be the fuselage.
  • Roll a sheet into a cylinder around that 24-inch length of PVC pipe. Note, that pipe isn’t going into the air. It’s just a mold for the rocket so it’s the same width as the launch tube.
  • Tape the paper seam with masking tape, being careful not to tape it to the pipe.
  • Make the fuselage fit snugly, but not too tight. It needs to slide easily into position on the launcher, but not get stuck. “People tend to roll it like a death grip,” Lutz says. “The best case scenario there is the nose cone blows off.”
Blowing-up Stomp Rocket Menino Community Center

Flickr / Learn 2 Teach

Get Creative With The Nose Cone and Fins

Before your kid throws a bunch of glitter on the rocket’s fuselage and misspells NASA in crayon, they need to build a nose cone and fins from the remaining paper.

For the nose cone, make sure it’s air tight and test out different iterations. Some could be shorter and stubbier. Others can be longer and sharper. “I used to tell students I saw chewing gum that they should stick it in the nose cone. Adding a little weight helps.” Think of it like an arrow: the head weighs more than the tail.

Next, tape fins onto the rocket’s base. According to Lutz, fins are the biggest variables in terms of performance. They create drag for stability, but not enough to hinder performance. “Proportional” and “firm,” are JPL’s terms. Try experimenting with different weights, sizes, number, and shape of fins.

If you have an aerospace engineer in the family, it’s worth a FaceTime.

NASA SFX Campers Test Their Stomp Rockets

NASA

T-Minus 10, 9, 8 …

After giving your rocket a sweet name (you might want to stay away from Falcon 9) you’re ready to launch. Shoot for a calm day, or find a launch site behind a building or other windbreak. Once everything is in place, it’s stompin’ time. Just make sure they use good technique. Lutz says to make sure their feet are perpendicular, not parallel, to the bottle. Just steer clear of the flight paths of major metropolitan airports, because this thing is going stratospheric.

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