In this video we can see an astronaut on the payload bay of the Space Shuttle, placing what looks like a radar reflector, during an EVA. The following image is a frame from the video in question:

astronaut placing radar reflector

Radar reflectors have many applications. They are usually mounted on small boats to increase their radar fingerprint (source), and they are part of the emergency equipment on board a lifeboat.(source)

However, I had no idea that they were used on board spacecraft, so I find it very intriguing.

  • Why is this astronaut placing a radar reflector?
  • Are radar reflectors used consistently during space missions or was this just part of an experiment?
  • Can anybody identify which STS mission this was?

1 Answer 1


This was mission STS-61B. The giveaways are the ACCESS payload box and the Mexico logo on the PAM-D sunshield.

The last task of the first EVA was to deploy a small satellite (the radar reflector) to be used for station-keeping experiments.

Ironically, the shuttle radar was failed, so the targetting was all done visually.

This was definitely part of an experiment; I am not aware of radar reflectors being used "consistently", at least in the shuttle program.

Here is Woody Spring deploying the satellite/reflector (a few frames after the picture in the question)

enter image description here

source (scroll down past the pictures to get to the text)

  • 1
    $\begingroup$ So this footage dates back to 1985! Amazing! The link that you provided has very good information about the mission events. Interesting story. Thank you. $\endgroup$ Commented Jun 27, 2017 at 13:42
  • $\begingroup$ By "deploying" is it safe to assume he simply "dropped" it into space at that altitude? Or was it attached to some other satellite piece? $\endgroup$ Commented Jun 27, 2017 at 19:16
  • $\begingroup$ It seems that the reflector was the satellite. More info at the link in the answer. $\endgroup$ Commented Jun 27, 2017 at 19:24
  • 1
    $\begingroup$ @SarahBailey Yes, that's correct. Astronaut Woody Spring released the radar reflector into space orbiting completely free, in fact, it stayed about eighty days in orbit. For comparison, the STS-61B mission only lasted 6 days and 21 hours. $\endgroup$ Commented Jun 27, 2017 at 20:23

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