• Students will investigate why researchers grow protein crystals on an International Space Station.
  • Students will grow crystals.
  • Students will think about how the microgravity environment may change how they do the experiment.


  • 250 milliliters of warm water
  • Spoon
  • Salt
  • Pencil
  • Two drinking glasses
  • 15 centimeter piece of string


  • Pour the 250 milliliters of warm water into a glass
  • Pour salt into water, stirring until the salt dissolves. Continue adding salt until no more will dissolve. (Some undissolved salt will re-main at the bottom of the glass)
  • Pour the clear salt water into another glass. (Leave the undissolved salt in the first glass)
  • Tie the string around the pencil
  • Lay the pencil across the top of the glass, allowing the string to hang down into the water
  • Place the glass in a protected place
  • Check the glass weekly
  • Once crystals form, check daily


  • How long does it take for the first crystals to form?
  • What do you observe on your daily observations?