Jewel of the Solar System: Part 7 – Drop Zone! Design and Test a Probe

In this activity, split into four or more about 40-minute sessions, youth will:

• Build a parachute and probe that can descend and land safely from a high point.
• Creatively use the information learned in previous lessons to perform science and engineering techniques of design, construction, and testing.
• Learn the value of experimentation that allows testing, improvement, and refinement as a professional part of engineering.
• Activity Goals: Include data from readings in their experimental design; use experiment and analysis to study, force, motion and mass; consider real-world challenges in their parachute/probe designs, such as proper descent and on-target landing on varied surfaces using the "habits of mind" of engineers.

Note: This activity is part of the Jewel of the Solar System activity guide, which includes:

1. What Do I See When I Picture Saturn?
2. Where Are We in the Solar System?
3. Discovering Saturn: The Real "Lord of the Rings"
4. Saturn's Fascinating Features
5. My Spacecraft to Saturn
6. All About Titan and Huygens Probe
7. Drop Zone! Design and Test a Probe (current activity)
8. Celebrating Saturn and Cassini

• Classroom or cafeteria for construction; gym or schoolyard for testing.

• Find location for later testing parachutes and parachuting probes (in Session 4).

• Copy the student "Parachuting Probe Packets."
• Nest the pages and fold them. Check to make sure the pages are in order. Staple into booklets (5.5 x 8.5 inches) using a long-arm stapler.
• Set up a safe testing area from which to drop the probes. If it is not safe to use an elevated, protected, common traffic area, use a ramp or volleyball net. Draw a “target” landing area with chalk or place a hulahoop.
• Make a clay ball for the probe drop, to use as a baseline time test.
• If you have access to a small portable wading pool, use this for the landing in liquid test. (Be sure the students understand that there will not be liquid water on Titan’s surface, though there are lakes of liquid methane.)
• For the volleyball net drop zone, wrap the probe in its parachute and launch by throwing it over the net. The parachute must open and float to the ground without harming the probe. The net establishes a minimum height for the probe to climb before falling to Earth, and also a “safe zone” that is kept student-free until all probes have been thrown. Probes are retrieved after throwing.

• Students who don’t have experience with building activities or who need opportunities to increase their fine motor skills may need additional time or days to re-visit their structure. They may also need technical assistance from you.
• You can group students who have more experience with those who have less — remember, one child may take over and may require careful facilitation.
• Remind students that a “failed” probe is an opportunity to re-design and not a reflection of the team’s potential or ability.

• Allow 20 minutes or more to make the probe packets and to set up construction materials for the parachutes and probes.
• To encourage thinking like engineers, give the measurements for the parachute and string to students in metric units. To convert inches to centimeters (cm), multiply inches by 2.54. Example: 14 inches = 2.54*14 cm = 35.56 cm.
• Students may have “unlimited” or set distribution from the type and amount of materials you gather. You can set “prices” on the materials, and give students a limited budget or you can give them a set of supplies and a budget to buy more.
• If napkins or tissue paper are not available, opened sheets of 2-page newspaper are an option. Cut the 4 pieces of string the same length as the edge of the paper and use a heavier test object.

For time limitations, students can conduct a parachute inquiry only. The questions in the "Parachuting Probe Packet" can be applied to parachutes rather than probes. You can still design/re-design for a slow descent in a targeted area. Discuss “controlled testing” where only one design factor changes at a time: material type, string length, or washer size.

For engineers, experimentation to test, fail, learn, and improve is a natural part of the design-build-test process, and is not considered a failure but an opportunity for progress and eventual success in space.

Engineers design and build spacecraft and instruments as solutions for science objectives rather than for looks or for their own personal goals.

• Control: In an engineering experiment, a condition that doesn’t change.
• Controlled Test: An experiment where only one condition changes from trial to trial, so that the effects of that condition are clear.
• Engineering Design Process: Consists of these steps – identify problem; brainstorm; iterate the design: build, test and evaluate, and redesign; share solution.
• Impulse: Impulse is the force of an impact multiplied by the amount of time the force is exerted. There are two types of impulse: hard and fast, and soft and slow.
• Variable: The condition that changes in an engineering experiment.

Give the students time to complete the last page of the Parachuting Probe Packet — “Questions for Spacecraft Engineers.” Bring the group together, and ask each question and get responses from the students. It is a good idea to chart their responses.

Ask the following questions and record student responses on the board or on chart paper:

• Which designs or design elements seemed the most stable, or added stability?
• Which parachutes seemed to take the longest to land?
• Which designs or design elements seemed to hit the target, or closest to the target, most often?
• Is there a “best weight” the probe needs to be in order to land accurately?
• Is there a relationship between parachute size and probe weight?
• What do you like best about working like a spacecraft engineer?
• What do you think are the biggest challenges they face?
• What questions do you still have?

As you circulate and look at the students’ writing, ask yourself the following questions:

• Is the experimental plan clear and sequential?
• Has the data been recorded in an organized way?
• Does the reflective writing show evidence of critical and creative thought?

• In the week prior to this activity, alert the students that they will be building a model of a probe — encourage them to describe to their families what a probe does, to get their family’s ideas about what kinds of household recyclable material to use, and to ask them to contribute to the collection of materials. Tired of the same old home videos? Check out videos from another world — Saturn!

• Putting a probe into space around another planet takes a team of dedicated scientists, engineers, and others at NASA working together. Learn about some of the people who make space exploration possible.

Credit: Georgia Institute of Technology

Ayanna Howard is a robotics engineer at Georgia Tech University. She designs, builds, and programs robots to help scientists (and humans) perform jobs that are either too dangerous, tedious, or currently impossible for humans. Her interest in engineering and NASA was sparked one day in junior high school, when people from the Jet Propulsion Laboratory came to her school to judge the students’ parachute egg-drop contest. “I decided at age 11 that I wanted to create artificial limbs for people. I planned to go to medical school, but discovered I hated biology in high school — especially dissecting frogs. Then I heard about robotics and realized that, if I became an engineer, I could do exactly what I wanted to do — and no frogs!”

When talking to young students, Ayanna says, “It’s really rewarding when you hear people say, ‘Maybe I can do that,’ or ‘I want to hear more.’ I look at their eyes and think: Wow, I really do have a cool job.”

Read more about Ayanna

Resources

• Hear students share their stories of their internships at JPL.
• Are there volcanoes on Titan?
• Find lots of educational resources on the JPL education website.

Taking Science to the Next Step

Special thanks to Dr. Jean-Pierre Lebreton and Dr. Ralph Lorenz, Cassini mission scientists, for the extension activities offered here.

• Optimization exercise: Students can experiment with parachuting paper or cardstock cone-shaped “shields.” A broad cone gives more drag (slows you down more) while a narrow cone is more stable, given the same amount of material. Students can first measure the time it takes a washer or ball of clay to fall from a given height. Parachuting shields earn points based on how much more slowly they fall. They also earn points for stability — specifically for how close they fall to a target drawn on the ground. Points can be “charged” for how much material is used to construct the shields. There should be some optimum design where the cone is sharp enough to fall in a stable fashion and to land close to the target, but not so sharp it needs lots of material to have enough drag.
• Characterizing an unknown surface: One of the Huygens Probe’s responsibilities was to characterize the surface of Titan from the impact as recorded with onboard instruments to measure the probe’s acceleration and deceleration. You can model this for the children by creating different surfaces hidden enclosed in cardboard boxes: for example, sand, gravel, brick, and water. Students can make a hole in the box top, and drop a “probe” (marble) into the hole at the top of the box, and try to guess what the surface is from the sound it makes. If possible, set up a microphone/computer hook-up, so students can “look” at the sound.

Literacy

• Give each team of students time to write a set of step-by-step directions to go with their drawing to facilitate construction of a probe. Have teams exchange plans and build.