There are several news items about the recent passing of astronaut Bruce McCandless II, and they generally refer to his work developing, and then using the Manned Maneuvering Unit (MMU).

Access to the original New York Times article describing McCandless' first use of the MMU is provided in a free sample from their archive TimesMachine.

Question: What is the farthest distance that an astronaut has been free-floating in space from any spacecraft other than a space suit, presumably with an attached propulsion unit?

I'm not sure if a "how many times" question should be asked separately, or if it's better to include here. I'm guessing this hasn't happened very many times.

NASA video of McCandless: Astronaut Bruce McCandless II Floats Free in Space, video and much more: NASA Remembers Astronaut Bruce McCandless II.

below: "This Feb. 7, 1984 photo made available by NASA shows astronaut Bruce McCandless II participating in a spacewalk a few meters away from the cabin of the Earth-orbiting space shuttle Challenger, using a nitrogen-propelled Manned Maneuvering Unit." Photo: AP. From here

enter image description here

below: "On Feb. 12, 1984, Bruce McCandless ventured away unrestrained from the safety of his spaceship, which no previous astronaut had done. He could do it because of a brand-new, jet-powered backpack." Photo: NASA. Cropped from here.

enter image description here

  • 3
    $\begingroup$ I assume the moon walks aren't eligible, despite probably having the distance record? $\endgroup$ – PearsonArtPhoto Dec 23 '17 at 15:34
  • $\begingroup$ @PearsonArtPhoto that's a good point! The "human satellite" term isn't clear enough. I'll edit the question. $\endgroup$ – uhoh Dec 23 '17 at 15:41
  • $\begingroup$ This first MMU mission is probably it. Not sure how to confirm though. They were only used on three missions in 1984 and never again :( $\endgroup$ – Organic Marble Dec 23 '17 at 15:49
  • $\begingroup$ There was actually a 4th, but with a different unit, the SAFER. $\endgroup$ – PearsonArtPhoto Dec 23 '17 at 15:55
  • 1
    $\begingroup$ Comment collapse blinds me yet again hah. $\endgroup$ – Magic Octopus Urn Jul 11 '19 at 3:50

None of them were particularly far. The first flight shows a distance of 325 feet (99 m). The best record I can find for STS-41-C says the shuttle came within 200 feet (63 m) of the satellite, and the last was done via the MMU. and the best guess I have from STS-51-A is 35 feet. The tests of SAFER on STS-64 was just around the robotic arm, so I'm assuming less then that.

Best guess: 325 feet (99 m). Small chance of a further distance.

  • 4
    $\begingroup$ " Bruce McCandless then moved 45 m (150 ft) out from Challenger, returned to the payload bay, flew out to 96 m (315 ft) and returned, then moved out again to about 99 m (325 ft). " - from the first link. $\endgroup$ – Organic Marble Dec 23 '17 at 16:21
  • 1
    $\begingroup$ Woops... Will correct, good catch! $\endgroup$ – PearsonArtPhoto Dec 23 '17 at 17:11
  • 2
    $\begingroup$ It would be great if you could put the meter count into your answer (comments might be deleted more easily). $\endgroup$ – Felix Dombek Dec 23 '17 at 21:51
  • 2
    $\begingroup$ Confirmation; astronaut Michael Lopez-Alegria (current president of the Association of Space Explorers) can be heard to round it to 100 meters in a BBC interview here between 14:00 and 19:47, along with some recordings of astronaut Bruce McCandless himself. $\endgroup$ – uhoh Dec 24 '17 at 13:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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