Scott Kelly – anti-science fighter, stellar science communicator, International Space Station (ISS) spaceflight record holder, and occasional microgravity prankster – is clearly a marvelous human being. He’s now even more of a spectacular spaceperson after braving the lawless land of Reddit, where he took part in an Ask Me Anything (AMA) session.

In conjunction with Biography at A+E Networks, the former NASA astronaut took questions from people, but instead of responding via text, his answers were filmed and documented for all to see. As spotted by Space.com, he was asked what the creepiest thing he’d ever seen while up on the ISS was. He opined that it was a “gallon-sized ball of urine mixed with acid” that he had to, rather grimly, clean up.

“It's sulfuric acid that is mixed with the urine… basically keeps the toilet from clogging up,” he added. Not exactly something you want to get into your eye. So what else did Kelly have to say?

“Well the first time you launch, you think ‘well, I’m about to do the coolest thing I’ve ever done',” Kelly said, in response to a query about his mind just prior to launch. “’Oh, and by the way, I could get killed doing it’,” he added.

Kelly also noted he’s not a hoarder, in that he doesn’t really steal or otherwise collect space memorabilia. “I feel like I’m space memorabilia, so I don’t feel like I need anything else,” he chuckled.

The former Navy captain also touched on the subject of the so-called Orbital Perspective, the revelatory feeling of awareness often reported by spacefarers. Kelly describes it as being “more empathetic to the environment and the human condition,” noting that it didn’t necessarily make him smarter while aboard the ISS, but changed him for the better.

The interview is easily worth watching in full. It’s strangely moving listening to Kelly’s description of a dream he had while up on high, featuring his astronaut brother and himself staring back, from space, at the ISS covered in snow and ice.

All of this is an interesting juxtaposition to the interviews I conducted with two of NASA’s newest astronaut candidates back in 2017, Jasmin Moghbeli and Zena Cardman. Cardman, who’s still in training (alongside Moghbeli), said that she has “no idea what to expect” when it’s her turn to head into space.

“From what I understand, this job continues to feel surreal and fake until that moment that you lift off. But I think getting to see the curve of the Earth against that black background – it must be completely life-altering,” she noted. “I can’t even imagine what it’ll be like, but I hope I’ll be able to convey that back home.”