Lesson Idea | Make a Planetary Exploration Balloon

Subject: Science
Grade Levels: 3-12
Time Required: 30-60 minutes

Overview

In this activity, students will design a balloon and gondola system capable of supporting weight. Students will then determine the mass needed to cause the balloon to ascend at a given rate, descend at a given rate, and/or maintain a constant altitude over a set period of time.

Materials

- Helium balloons (2-3 per group)
- Paper or plastic cup, or other small container (1 or more per group)
- String or ribbon (approximately 1 meter per group)
- Meter stick, ruler, or measuring tape
- Stopwatch, smartphone timer, OR online timer
- Small objects, such as plastic beads, metal washers, or other classroom and household items to serve as ballast
- Tape (transparent, masking, etc.)
- (Optional) scale for measuring mass
- (Optional) hanging scale for measuring the upward force of the balloon

Management

- Have a few extra helium balloons in case some pop.
- Keep the activity indoors to prevent balloons from floating away and contributing to ground and water pollution.
- Consider taping measuring strips against a wall or flat surface so students can see their balloon’s altitude.
- Older students may calculate the buoyant force (see Extensions) before testing to determine the mass needed for the challenge(s).

Procedures

1. Tell students they are going to simulate a scientific balloon mission by designing a balloon and gondola system that will ascend or descend at a designated rate or maintain a steady altitude while supporting mass in a container.

2. Share some images of scientific balloons and describe some of the ways NASA uses or plans to use high-altitude balloons as described in the Background section.

3. Ask students to describe the forces they will have to consider while completing the challenge(s). Explain terms (e.g., gravity, weight, buoyancy, lift) as necessary, depending on student knowledge.

4. Consider having older students complete the force calculations as described in the Extensions section.

5. Have students come up with and sketch a design for their balloon and gondola system that uses string, tape, a cup and a balloon. Remind them they will need to design a way to hang their gondola from the balloon so that it will support items placed inside it.

6. Ask students to predict how much mass in kilograms (or how many of a certain item) will be needed to accomplish one or more of the following challenges:

- Maintain altitude: Students must find the appropriate amount of mass to place in the cup that will cause the balloon to float and maintain a steady altitude of approximately 3 feet (1 meter) for 30 seconds. (Fb = Fg)
- Controlled ascent: Students must find the appropriate amount of mass to place in the cup that will cause the balloon to ascend at a rate between 10 and 20 inches per second (0.25 to 0.5 meters per second). (Fb > Fg)
- Controlled descent: Students must find the appropriate amount of mass to place in the cup that will cause the balloon to descend at a rate between 10 and 20 inches per second (0.25 to 0.5 meters per second). (Fb < Fg)

For futher information, please visit Jet Propulsion Laboratory website.