https://twitter.com/elonmusk/status/943420026593337344@elonmuskFalcon Heavy at the Cape
The titanium fins are bigger, so they felt the needed more control authority on the side boosters?
Quote from: Req on 12/20/2017 09:48 amhttps://twitter.com/elonmusk/status/943420026593337344@elonmuskFalcon Heavy at the CapeIt's worth noting that the first of the pictures (the one from above) is obviously a stitch of more than one picture and has resulted in some missing features just above the Falcon Heavy logo (like the separation pushers, which are clearly visible in the second picture)
I'm curious as to why the outer cores have Ti grid fins rather than the Al of the center core. Could that be because the outer cores will be released lower in the atmosphere and need more control, since they will be relatively close together and have to redirect more quickly while performing a more complex maneuver (RTLS, boost back etc) than the center core, which will just go out to an ASDS somewhere out at sea?
The large frame connecting the boosters surprised me. Guess I was just going by the early renderings, but it's quite big.
What those renders from 2 years ago didn't show was the connections at the bottom.
Larger versions
Interesting the side boosters have Ti grid fins while the centre core has Al fins. I would have assumed the other way round as the centre core has the hotter reentry.
Anything special about the PAF which can only be partly seen?
I wonder if they are production-constrained on the Ti fins? It was discussed here (tea-leaf-reading on some ambiguous tweets from Elon) that perhaps the first prototype Ti fins were machined from a solid block while the production fins would be forged, and that the forging process had significant setup costs/lead time, so they might not want to get that going until the Ti fin design had been thoroughly vetted... presumably including on this FH maiden flight.So there might be only two sets of prototype Ti fins in existence, and they've been dedicated to the two FH side boosters... explaining why some other recent high-energy F9 flight candidates haven't opted for Ti.For that matter, they obviously see no reason *not* to use Al fins, like on the center booster here, so Al not be end-of-lifed with F9 block 5. Put another way, the only "problem" with Al fins is limited reusability, not functionality (for F9; FH needs the extra control).