Here's a link to am AMA he hosted, you can explore his comment history from there I guess:

https://www.reddit.com/r/IAmA/comments/q9qzn/iama_former_nas...

None beyond the ama/username link That spare_account provided. It’s been 4-5 years at least, most of the stuff i read was about his work on the shuttle, people arguing with him about various engineering topics.