Challenge Five

What happens to the bones of the astronauts?

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It is very interesting to study the effect of space travel on the astronauts.  The effect of zero gravity on their bones is particularly fascinating.

alien and astronaut clipartHYPOTHESIS:

What do you think happens to the astronaut’s bones while he or she is in space?  What is your hypothesis?


Students should list their hypotheses or write a list of inquiries regarding the prior questions.  Since the students can not go into space, they will have to do their research by reading books or using the internet.   Students might be able to communicate with an astronaut or a scientist at NASA through the internet.

Sample questions are:

  • What happens to each of the different bones in the skeleton in space?
  • Do the same changes take place in all bones?
  • How long does a person have to stay in space for changes to occur in a bone?
  • What happens to the bones in the ear?
  • What do the astronauts do to help protect their skeletal bones?  ear bones?
  • Can the height of an astronaut change in space?
  • What preventative medical measures are being used to help astronauts prevent the development of  bone problems in space?


This activity is intended to demonstrate one change that can take place in the skeleton of an astronaut. 

The teacher will have to measure the height of each student.  Students can use only one metric ruler and they must design and make a measuring system to determine the height of each student in the class.  All students must use the same measuring system and that system must be in metric units.  The measuring device must show mm.  Differences should be recorded in mm.

The teacher measures each student twice.  Students should not know about the second measurement until all students are measured the first time.  The teacher measures each student.   Each student is told to stand normally and be relaxed.  The height of the student is recorded.  The students in the class are measured a second time but this time the students are told to keep their vertebral column straight and stretched as far as possible.  The results are recorded.

Each student determines the amount of change in the length of his or her skeleton.  The class can collect the data and analyze the data.  They can graph the data.  What do the results of this activity tell you about the vertebral column?

The results should show that each student should have greater height when he or she stands straight and stretches his or her vertebral column.  It shows that the vertebral column can be stretched to become longer. 


Research what happens to astronauts in space. Students should develop their own questions.  Here are a few sample questions that could be used only if they are needed to get the students started toward developing their own inquiries.

  • Can an astronaut’s height increase or decrease in space? 
  • If ‘yes”, where does that difference in height come from? 
  • What bones are involved?  Is that difference in height only from bones?
  • If “no”, what else happens to produce the difference in height? 
  • Why do these changes occur?
  • What force is involved in determining your height?
  • What happens to that force in space?
  • Do astronauts feel the change while they are in space?  If “yes”, what do the astronauts feel?


©2010 Elinor W. Semel   All rights reserved.