Student Activity #2

Large distances cause a communication time delay

[Sojourner navigating rocks in the Mars Yard]





  1. The first person in line is the robot.
  2. The last person in line is mission control.
  3. The other people in line represent the "time delay."
  4. All teams begin at the same time.
  5. When the teacher says "Begin," mission control decides on an object to have the robot retrieve. Mission control needs to decide what commands need to be given to the robot, one command at a time, in order to have the object retrieved.
  6. Mission Control whispers one command to the person next to them, that person repeats whispering the message to the person in front of them, and so forth until the command reaches the robot.
  7. The robot performs the command and tells the person behind him or her that he or she has done so. That person informs the person behind him or her, and so on, until the message reaches mission control.
  8. Mission control sends another command in the same manner.
  9. When the robot has retrieved the object, he or she goes to the end of the line and becomes mission control. The person at the head of the line now becomes a new robot.
  10. Repeat until all objects have been retrieved.


Extending this activity:

[Live from Earth & Mars]__________________________________________________