# Jeffrey Hoffman on Reddit (u/jhoffma1)

Part of Scientists on Reddit, researched with Autumn (https://www.autumn.ai) from public sources. Updated 2026-11-07. Interactive version: https://www.autumn.ai/resources/scientists-on-reddit/jeffrey-hoffman

Jeffrey Hoffman: NASA astronaut, first Hubble repair mission, MIT professor.

- Reddit account: [u/jhoffma1](https://www.reddit.com/user/jhoffma1/) (AMA only)
- How we know it's theirs: [The 2017 r/IAmA AMA, posted from this account](https://www.reddit.com/r/IAmA/comments/71c4i2/)
- Where they post, in the records we retrieved: r/IAmA (56)
- Known activity in the posts we found: 2017 to 2017
- Wikipedia: https://en.wikipedia.org/wiki/Jeffrey_A._Hoffman

## Moments

### u/jhoffma1 in r/IAmA, Sep 20, 2017 · Personal story

Replying to a redditor:

> I imagine that lots of stuff gets loose and travels around the cabin in zero-g, so my question is what's the most surprising thing you found floating in front of your face?

> The most surprising thing that anyone found floating in front of his face was, I think, his own hand! When you are weightless, you can lose track of your arms and legs if you are totally relaxed. A sleeping astronaut awoke to see a "mysterious hand" floating in front of his face. It took quite some time for him to realize that it was his own hand!

Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9pkvi/ · 6 points as of Nov 7, 2026

### u/jhoffma1 in r/IAmA, Sep 20, 2017 · Personal story

Replying to a redditor:

> What was the greatest adversity you faced during your time in space? How did you address it?

> The most critical mission was the rescue/repair of the Hubble Space Telescope. On the first day, after replacing the gyroscopes, the main door would not close, which would have doomed the telescope. It took us an hour to figure out what the problem was and how to solve it, which involved using a standard tool in an unconventional way. But that's what astronauts are supposed to do - solve problems.

Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9n3ll/ · 6 points as of Nov 7, 2026

### u/jhoffma1 in r/IAmA, Sep 20, 2017 · Explains things

Replying to a redditor:

> What do you do when something dusty or anything like that starts floating around? How do you stop it prom hurting people or damaging stuff? Thanks!

> Dust in space is a real problem, because it doesn't fall to the ground. The air is constantly circulated through filters to remove dust and lint, but we need to be careful to minimize the amount of dust created - for example no woolen clothes (lint) and no cashew nuts (too many crumbs).

Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9mqfq/ · 4 points as of Nov 7, 2026

### u/jhoffma1 in r/IAmA, Sep 20, 2017 · Behind the scenes

Replying to a redditor:

> What's the most interesting experiment that you were a part of aboard the space shuttle?

> On my last flight (STS-75 in 1996) we deployed the tethered satellite, a 1.5 m diameter sphere that remained attached to the shuttle by a 20 km long wire. Looking up at the wire disappearing into space, I felt like Jack looking up at the beanstalk!

Full thread: https://www.reddit.com/r/IAmA/comments/71c4i2/comment/dn9lu8f/ · 22 points as of Nov 7, 2026