Live Hammock Video Chat RIGHT NOW

I was, yes. But 4 hours of stuff is a long time to watch other people ask you questions. :)

Patrick W. Gilmore

Were you able to still view the link?

Smarter Every Day

Thanks for taking time to do this! I can't believe it went on for four hours. In the stream I said I would like more content, but I didn't mean for you to take any more time away from your family to do so. Just saying. It was fun to chat, though. Happy Father's Day!

Austin Burnham

Thanks so much for taking time to do this! It's very much appreciated.

DARNIT! (Or something stronger.) Can't believe I missed it. Have to watch my Patreon mail more closely in the future.... Either way, thank you for giving some of your day to your supporters. Even though I missed it, I appreciate it.

Patrick W. Gilmore

Thanks for doing this -- my internet cut out partway through, but it was great of you to take the time for this!

My question wasn't (at least meant to be) a softball question. My very vague undertsanding of rocket engines is entirely at the level of the thrust/momentum transfer/exhaust velocity, which is basically a one-dimensional way of thinking about it. Understanding why there's an engine bell I think takes a 3-d understanding which I really don't have. I think about it whenever I see any of the engines on, particularly, the Apollo rockets. As of April, I have now seen all 3 relatively space-worthy Saturn 5 rockets on public display, plus the outside one at the Huntsville museum. As far as "vacuum engine" term, in the books I have on Apollo, I've heard the J-2 referred to as a "vacuum engine", or certainly the one on the Saturn 5 3rd stage, but not, say, the F1 engines on the first stage. What really got me thinking about the expansion ratio was the fact that the F1 engine bell is in 2 separate sections. Those first stages were often transported with the lower part of the bell detached. They put them on for flight, but they were removed at other times, so I realized that the bottom half of the bell was clearly very important, but it doesn't how up in a purely simplistic 1-d imagining of a rocket engine. Thanks for address it! Your response combined with some of the people in the chat helped. I also now have stuff to look up.

Craig P Steffen