I'm watching the live TV from NASA broadcasting the ISS / SpaceX Dragon docking and I've seen a red light and a white flashing light. See them at the bottom of this image

screenshot from NASA live TV.

What are they for?

  • 4
    $\begingroup$ Navigation lights. If you see a spaceship the red/green split, and white tail mast tells you direction it is going. (Making a bad boating joke here). $\endgroup$
    – geoffc
    Aug 16, 2017 at 13:14

1 Answer 1


Navigation lights. Red on port, green on starboard, white on top, and yellow on bottom. The white light is also usually used as a tracking light from distance.


  • 4
    $\begingroup$ Really? Red/Green/white? Just like a boat! I was joking earlier! Yellow for the bottom that is not useful on a boat. Cool. $\endgroup$
    – geoffc
    Aug 16, 2017 at 23:03
  • 2
    $\begingroup$ @geoffc -- And just like an airplane. The similarity is intentional, as are the terms docking and berthing. $\endgroup$ Aug 17, 2017 at 3:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.