Make a Paper Mars Helicopter

Ask students to describe how a helicopter flies. Elements of their description should include fast-moving, horizontal, rotary blades.

Explain that the rotary blades are slightly angled so they can push against the air and lift the helicopter off the ground.

Ask students what else rotates and pushes against air (e.g., a fan). Ask students to compare and contrast a fan with a helicopter. For example, both move air in similar manners, but the helicopter moves a large volume of air downward while a fan usually moves a smaller volume of air toward us.

Explain that a helicopter moves so much air with its large, fast-moving blades, that the force of the blades against the air can overcome the weight of the helicopter and push it up off the ground. The helicopter is working against the force of gravity – which is constantly pulling the helicopter down toward the ground – and generating an upward force called “lift” by rotating its blades through the air. When the force of lift is greater than the force of gravity, the helicopter rises from the ground and flies.

Ask students if a helicopter might fly differently on the Moon or Mars and why. Note: The Moon doesn’t have an atmosphere in which to generate enough lift to fly. Mars has a very thin atmosphere that may be able to support a small helicopter with very fast-moving blades. NASA’s Mars Ingenuity helicopter will test whether this is feasible.

Show students this video about NASA’s Mars Ingenuity helicopter:

Ingenuity is a technology demonstration. In other words, the goal is to see whether it can fly on the Red Planet and study how the design could be improved for a future Mars helicopter.

Explain to students that engineers had to do a lot of testing to figure out what design worked best. Show students this video about testing Ingenuity at NASA’s Jet Propulsion Laboratory:

Explain to students that they will now experiment with building a paper helicopter and try to create the best design.

To have students build their helicopters as an independent project, have them follow the instructions (including a video tutorial with subtitles en Español) here. Teacher-directed instructions continued below.

Have students cut along the dashed lines of the helicopter template.

Have students fold the propeller blades, A and B, in opposite directions along the solid lines. The X and Y panels fold toward the center, and Z is folded upward to give the body of the helicopter rigidity and lower its center of gravity for more stable flight.

Have students do a test flight by standing up, holding the helicopter by its body, raising it as high in the air as they can and dropping it. Ask them: What do you observe? Which way do the blades turn? Drop the helicopter from a higher spot. (Climb a few stairs or stand on a step stool.) How does the performance change?

Ask students what they might change about their helicopter to affect its performance. Encourage them to make one change to their helicopter and do another drop. If students have a hard time thinking of changes, suggest they try making one more fold on the bottom of their helicopter, or try shortening or changing the shape of the blades. How does the performance change? Why does the chosen change have this effect? Have students share their changes and results.

Ask students if they can figure out how to make their blades turn faster or slower. Ask them to figure out how to make their blades turn in the opposite direction.

Ask students to think about how they might improve the performance of their helicopter and make another one that is different from their first. Have them use a different kind of paper or make a much smaller or much larger one. How big of a helicopter can you make that will still work? How small of a helicopter can you make? How do helicopters with different blade sizes compare in performance? What size works best? How do you define "best performance"?

Ask students what happens to the helicopter when they drop it from higher locations. Most students should say that the blades rotate more.

Ask students to drop one of their helicopters and try to count how many times the blades rotate. It’s impossible! Ask how they might solve the problem of counting rotations. Older students may have smartphones and be able to record a slow-motion video. Younger students may be stumped by the challenge.

Have students with access to a slow-motion video proceed in that direction. Have other students attach a straight ribbon to the bottom of their helicopter, stand on the end of the ribbon to hold it securely in place on the floor and drop their helicopter as before. Once the helicopter comes to rest on the ground, have them count the twists in the ribbon to determine how many rotations their helicopter made.

Have students design an experiment that will allow them to predict the number of spins their helicopter will accomplish from an unknown height. Ask students to measure several heights to drop from, using a measuring tape or nonstandard unit of measurement. Have them start dropping from the lowest point possible – usually about two feet from the ground – and recording the number of turns. Have them make a t-chart to record the distance they dropped from and the number of turns.

Have students repeat measurements for a variety of heights that they can easily reach.

Have students graph their results on an x-y plane.

Have students add the height of a step stool or stairs to the height they can reach and use their graph to estimate the number of turns their helicopter will achieve on a drop from that height. Have older students develop a rule for computing the number of turns from a given height.

After they’ve recorded their estimate, have students get on the step stool or stairs and drop their helicopter. They will need a peer or family member to hold the bottom of the ribbon steady on the floor.

As time permits, have students experiment with different helicopter designs and count and graph rotations. What designs rotate slowest and which rotate fastest?