Quote from: FutureSpaceTourist on 12/20/2017 09:05 amLarger versionsNote that the overhead view was photoshopped, a composite of at least two frames, possibly 3. The interstage is too short and it's missing the obvious stage separation pusher that's visible above the FH logo in the other shot.I guess they couldn't capture the entire vehicle from overhead in a single frame without gross fisheye distortion so they had to mosaic separate frames with significantly different perspective.Anyway, nice to finally see the mated hardware, the cores are actually a bit closer together than I imagined them to be due to the leg spacing, etc.
Larger versions
I'm sure this has been asked multiple times in the past, but what's with the strap holding up the center engines? I've seen it before on recovered cores being transferred back to the HIF, but not during rollout prep.
I have a question about the upper attach structure. I doubt we will know for certain how it is planned to work until we see the flight, but here goes:In the detail below, it would appear that the cross-struts that attach tangentially across the center core cannot remain on the center core -- at least where they are right now -- and still allow its grid fins to deploy and have full freedom of movement. But I would suspect the same thing of the side cores, were these struts to separate in the middle and depart with the side cores.Do they actually fold up along the side of the interstage on the center core? Do they stay with the side cores, giving them uneven airflow and thus requiring the additional control authority of the larger titanium grid fins? Or are they simply jettisoned at some point, a small amount of hardware given up to the rocket equation gods?Sorry if this has been discussed in detail elsewhere and I have missed it. It's not humanly possible to read every post in this forum and still maintain heavy life responsibilities... sigh...
They remain on the center core and pivot upward. You can see the latches just above the US flag.
I will be quite impressed with a strut system that has a hinge right where it encounters the greatest stress. When I see it fly, that is. It just seems counter-intuitive to place a hinge right at that extremely high-tension-stress location on the stack. I thought the folding struts were a CGI flight of fancy and expected a rigid structure of some kind would replace the kewl folding struts, to be honest.
Quote from: nacnud on 12/20/2017 05:45 pmThey remain on the center core and pivot upward. You can see the latches just above the US flag.Thanks. I thought those lumps up on the interstage looked like latch points. And yeah, I recall what the original CGI showed, but the SpaceX CGIs have not always been accurate, especially after several intervening years of design-fiddling.I will be quite impressed with a strut system that has a hinge right where it encounters the greatest stress. When I see it fly, that is. It just seems counter-intuitive to place a hinge right at that extremely high-tension-stress location on the stack. I thought the folding struts were a CGI flight of fancy and expected a rigid structure of some kind would replace the kewl folding struts, to be honest.I shouldn't have asked about this prior to the flight. Now I'll worry about it from liftoff all the way through side core sep...
I'd assume the primary vector for force transfer is at the pair of lower clasps holding the three octawebs together. These struts are likely just to prevent differential yaw/pitch, not to transfer force from the side boosters to the core.
Quote from: the_other_Doug on 12/20/2017 05:33 pmI have a question about the upper attach structure. I doubt we will know for certain how it is planned to work until we see the flight, but here goes:In the detail below, it would appear that the cross-struts that attach tangentially across the center core cannot remain on the center core -- at least where they are right now -- and still allow its grid fins to deploy and have full freedom of movement. But I would suspect the same thing of the side cores, were these struts to separate in the middle and depart with the side cores.Do they actually fold up along the side of the interstage on the center core? Do they stay with the side cores, giving them uneven airflow and thus requiring the additional control authority of the larger titanium grid fins? Or are they simply jettisoned at some point, a small amount of hardware given up to the rocket equation gods?Sorry if this has been discussed in detail elsewhere and I have missed it. It's not humanly possible to read every post in this forum and still maintain heavy life responsibilities... sigh...They are hinged at the attachment point on the core and fold up. If you look very closely, you can see that the slightly angled rods/arms above the cross-struts (attached to them at the center) have a narrow section and a wide section; those are hydraulic pistons that will retract, pulling the cross-struts up against the core, where they latch into the attachment manifold right above the flag.
Quote from: sevenperforce on 12/20/2017 06:29 pmQuote from: the_other_Doug on 12/20/2017 05:33 pmI have a question about the upper attach structure. I doubt we will know for certain how it is planned to work until we see the flight, but here goes:In the detail below, it would appear that the cross-struts that attach tangentially across the center core cannot remain on the center core -- at least where they are right now -- and still allow its grid fins to deploy and have full freedom of movement. But I would suspect the same thing of the side cores, were these struts to separate in the middle and depart with the side cores.Do they actually fold up along the side of the interstage on the center core? Do they stay with the side cores, giving them uneven airflow and thus requiring the additional control authority of the larger titanium grid fins? Or are they simply jettisoned at some point, a small amount of hardware given up to the rocket equation gods?Sorry if this has been discussed in detail elsewhere and I have missed it. It's not humanly possible to read every post in this forum and still maintain heavy life responsibilities... sigh...They are hinged at the attachment point on the core and fold up. If you look very closely, you can see that the slightly angled rods/arms above the cross-struts (attached to them at the center) have a narrow section and a wide section; those are hydraulic pistons that will retract, pulling the cross-struts up against the core, where they latch into the attachment manifold right above the flag.Are you talking about the yellow saddle piece? Because i'm wondering where it and the struts it's attached to go.
The left side booster also appears to contain the number 8 in the expected location, considering the two cores are 180 deg apart.