• 
  John M. Grunsfeld

  Himself
• 
  Sara Seager

  Herself
• 
  Charles Mattias 'Matt' Mountain

  Himself
• 
  Blake Bullock

  Herself
• 
  Jon Arenberg

  Himself
• 
  Jason Kalirai

  Himself
• 
  Amy Lo

  Herself
• 
  Lee Feinberg

  Himself

• 
  Adam Reiss

  Himself
• 
  John Mather

  Himself
• 
  Eric Smith

  Himself
• 
  Katheryn Friend

  Herself
• 
  Markus Kissler-Patig

  Himself
• 
  Julianne Dalcanton

  Herself
• 
  Nathaniel Kahn

  Narrator