Thanks for the link to that recent talk by Hans. I enjoyed it, even though most of what he described was familiar to me. But I did learn a couple of new things, at least for me.
— The FH center core engines were flight proven. I had always assumed that the entire center core was brand new, including the engines, I did not realize that the engines were not new. Maybe that information was out there and I missed it. That is significant because it means the cost of the first FH was even less than I assumed. So that led me to wonder if recent Block 3 and 4 stage recoveries were primarily done so that the engines could be reused?
— The lower connection points for the FH side cores are “hinges” that “unhinge” after the pusher mechanism at the upper connection points activates. I had assumed that pusher mechanisms were used for both the upper and lower connection points. I’m trying to envision what sort of hinge is used that can withstand the tremendous forces exerted on the base of the cores during ascent and then can passively disconnect itself as the side core rotates away from the center core, but I need a diagram to understand how that would work, and Hans didn’t offer any details. Fascinating bit of new information for me, in any case.
— Hans mentioned the massive deceleration force the side cores experience during landing and how it would be very uncomfortable to be onboard during landing. I wish he had given a G force number. But it was a good reminder that although the cores look like they just kiss the ground on impact, in the final couple of seconds before touchdown they undergo a dramatic deceleration. I get a sense of it from the video but really wonder what the G number is.
It was great to see Hans being effected watching the FH launch and land, obviously enjoying it, even after many viewings no doubt. I continue to have the same reaction every time I watch the video.
Thanks for posting links to those videos. Although it is a general presentation and most of what Hans said I was aware of, I of course learned some things and he is such a pleasant and engaging person that it is a pleasure to hear him speak.
His point that SpaceX is getting people excited about space again and how important that is, beyond achieving reusability and all the other accomplishments, was good to be reminded of. To accomplish SpaceX’s long term goal, people have to get excited about about humans exploring and living on other planets. If there is no public enthusiasm and support the long term goal is much harder.