Explore - Health in Space

Space Stations - Beans in Space!


Children perform 20 bicep curls with cans that model the weight of dried beans on Earth and the weight of the same number of beans on the Moon or in space. They explore how astronauts need to exercise each day — just like us on Earth — but for 2+ hours each day!

Activity Time

5 minutes

Intended Audience

  • Families or other mixed-age groups, including children as young as 4 years old with assistance from an older child, teen, or adult
  • School-aged children ages 5–7 and 8–9
  • Tweens up to about age 13

Type of Program

  Facilitated hands-on experience
  Station, presented in combination with related activities
  Passive program
  Demonstration by facilitator

What's the Point?

  • Astronauts — and kids! — need to exercise to stay healthy.
  • Because astronauts float in space, their muscles do not need to work as hard as they did on Earth, and they become smaller and weaker (i.e., begin to atrophy).


For the facilitator:

For Each Group of 1–3 Children

  • 3 opaque non-breakable containers (clean, empty coffee cans work well)
  • Tape (to seal the containers)
  • 3 ½ cups of dried beans, any type
  • Paper or foam to stuff inside the Earth and Moon cans so that the beans don't rattle
  • 3 labels, one for each can


  • Review the Beans in Space Facilitator Background Information and Explore! Health in Space Discussion Guide.
  • Prepare the three containers, each with different amounts of beans to model its weight on Earth, on the Moon, or in space.
    • Place three cups of beans into a can and label it "3000 Beans on Earth."
    • Place 1/2 cup of beans into a can and label it "3000 Beans on the Moon."
    • Label the empty can "3000 Beans in Space."
    • Make sure the lids on the containers are on tight or sealed so there can't be any peeking!
  • Provide the “Earth,” “Moon,” and “Space” cans in a bag or bin, or place them at a table so that participants can access them.

There are approximately 3,000 beans in 3 cups of navy beans. Placing a specific number on the container label will help the children to realize that even though the weight of an object may change in space, the mass of those objects will remain the same.

The day before the activity

Provide the “Earth,” “Moon,” and “Space” cans in a bag or bin, or place them at a table so that participants can access them.


1.  Share ideas and knowledge.

  • Introduce yourself. Help the children learn each other’s names (if they don’t know each other already).
  • Use the Explore! Health in Space Discussion Guide to draw participants into the activity and frame the activity with the main message:  Astronauts — and kids! — need to exercise to stay healthy.

2.  Exercise like an astronaut! Encourage each participant to lift the can labeled “3000 Beans on the Moon” in one hand and the can labeled “3000 Beans on Earth” up and down 20 times. Invite them to do the same “workout” with the can labeled “3000 Beans in Space” compared with the “Earth” can in the other arm.

3.  Compare observations and connect them to the “real world.” Prompt the children to compare their experiences lifting each of the cans with other children and/or family members. Prompt them to connect that experience to what astronauts experience in space.

For older children, emphasize the concept that weight and mass are not the same things. Although mass remains the same in space, weight changes in microgravity. Ask them if they think a can filled with 3000 dried beans — or anything else — has the same mass on Earth as 3000 beans in space or on the Moon.

4.  Explain that in space (a microgravity environment), astronauts’ muscles become smaller and weaker (i.e., begin to atrophy). Their muscles don’t have to work hard to lift their bodies or the equipment that the astronauts use — it is like lifting the “Space” can. In space, where there is no gravity for their muscles to pull against, their muscles become weaker. On the Moon, which has about 1/6 the pull of gravity that Earth has, future explorers’ muscles will get a little bit of a workout.  

5.  Conclude. Summarize that astronauts work out almost two hours every day while they are in space and even then, they still lose muscle mass. Kids and adults on Earth also lose muscle mass if we don’t exercise enough! There are many challenges astronauts face as they live and work in space. Daily life in space is different than life on Earth, but in both environments humans have the same basic needs.

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