Touchdown

In this challenge, students will use what they know and can investigate about gravity, motion, and forces to design and build a shock-absorbing system that will protect two "astronauts" when they land. Just as engineers had to develop solutions for landing different vehicle types on the Moon and Mars, students will follow the engineering design process to design and build a shock-absorbing system out of paper, straws, and mini-marshmallows; attach their shock absorber to a cardboard platform; and improve their design based on testing results.

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• Read the challenge sheet and activity details to become familiar with the activity.
• Gather the materials above for each group of 3-4 students.
• Prior to student arrival, you may want to assemble a class set of the above materials in gallon-sized resealable plastic bags for quick distribution.

In this composite image from 1969, astronaut Buzz Aldrin can be seen coming down a ladder from the mission's command module (or lander). Shortly after this series of images was taken, Buzz Aldrin became the second person to walk on the Moon. › See more images from the Apollo 11 mission.

Credit: NASA

Landing on the Moon is tricky. Since a spacecraft can go as fast as 18,000 miles per hour (29,000 km per hour) on its way to the Moon, it needs to slow down in order to land gently. And if there are astronauts onboard, the lander also needs to keep them safe.

NASA’s Artemis program will return humans to the Moon by sending the first woman and the first person of color to the lunar surface. A foundational piece of the program is NASA’s Space Launch System, or SLS, a rocket that will allow for human exploration beyond Earth’s orbit. SLS will be used in the Artemis program for a series of uncrewed and crewed missions, eventually carrying astronauts to the Moon during the Artemis III mission. NASA plans to continue sending missions to the Moon about once a year after that while also using SLS to launch robotic scientific missions to places like the Moon, Mars, Saturn, and Jupiter.

Spacecraft on their way to Mars may be traveling as fast as 13,000 miles per hour (21,000 km per hour) when they reach the Red Planet and need to slow down to land safely on the surface. Future missions to Mars will also need to safely land astronauts on the surface.

• What forces affected your lander as it fell? It accelerated [sped up] as it fell due to the pull of gravity. Air also pushed on it, and this air resistance slowed it down.
• After testing, what changes did you make to your lander? Answers will vary.
• Engineers’ early ideas rarely work out perfectly. How does testing help them improve a design? Testing helps you see what works and what doesn’t. Knowing this lets you improve a design by fixing the things that aren’t working well or could work even better.
• What did you learn from watching others test their landers? Answers will vary. But in general, kids will see that there are many ways to successfully tackle a challenge.
• The moon is covered in a thick layer of fine dust. How might this be an advantage? A disadvantage? If the dust layer is soft, it would help cushion a landing. However, if it is too soft, a lander could sink into it and get stuck. Also, the lander’s rocket engine could send up clouds of dust, which could get into the machinery and cause it to jam or malfunction.)

Refer to the engineering rubric.

• Hold a“ How High Can You Go?” contest: Have students drop their landers from two feet. Eliminate all landers that bounce out their “astronauts.” Next, raise the height to three feet. Continue in this fashion until a winner emerges. You can also increase the challenge by having kids add a third marshmallow “astronaut” to their cups.
• Test springs of different sizes: Have students see if the number of folds in an index card makes a difference in the amount of force the spring can absorb. Have them fold index cards with two, four, and six folds. Have them test to see how much of a difference these different springs make in how softly a lander touches down.

Have students use programmable microdevices to determine whether their landing was hard or soft by setting a threshold with an accelerometer:

1. Using a device such as a microbit, we can code simple parameters based on the deceleration of the lander. First try using the on shake function in input and changing it to 8g. This means whatever code we put inside this function will be triggered if the deceleration is greater than eight times the gravity on Earth. Inside the input function, place a show leds block, and draw a picture of what lights should display when the hard landing is triggered.
2. Next to this, place the on button input and set it to A+B. Place a clear screen block inside. This will allow the experiment to be cleared and repeated across all trials.
3. With the code downloaded to their devices, have students add a battery pack. They should secure the device and battery pack to their lander to ensure they stay connected.
4. As they refine their landers, they can increase the challenge by reducing the failure trigger from 8g to 5g or 3g to ensure a safe and soft landing.