I was looking at the pictures of the newly rolled out Falcon Heavy and I noticed these odd yellow extensions on the payload faring. What are they?
4$\begingroup$ I think that's part of the TEL, behind the fairing, not actually attached to it. $\endgroup$– Russell BorogoveJan 5, 2018 at 16:34
$\begingroup$ Iirc it was added just before the launch of X-37B but no idea why. $\endgroup$– jkavalikJan 5, 2018 at 16:34
1$\begingroup$ It looks like something used before launch, but not for the flight. The structures just below the fairing look like a mounting to the launch tower just behind the rocket and removed just before launch. $\endgroup$– UweJan 5, 2018 at 16:40
Those are part of the TEL (Transporter, Erector, Launch tower). Here's a video that shows the rocket and TEL from various angles. A shot from that video:
They are clamps that support the fairing when the TEL is horizontal. They retract once the TEL is vertical.
Originally, the acronym TEL was used for vehicles that carried and launched ballistic missiles. Some people have started using the acronym to refer to SpaceX's launch towers (which are somewhat unusual for Western rockets - most rockets are assembled and transported vertically, this one is assembled and transported horizontally, on the TEL).
4$\begingroup$ Assembling and transporting a rocket horizontally is unusual? Someone needs to tell the Russians that. $\endgroup$– MarkJan 6, 2018 at 0:59
$\begingroup$ I meant, I've never heard the acronym TEL used for space launch infrastructure until SpaceX started using it. $\endgroup$– HobbesJan 6, 2018 at 8:02
$\begingroup$ Meanwhile I've seen SpaceX engineers quoted saying they do not utilize a TEL, there's is a TE. I guess the "launcher" part is the pad & reaction frame. $\endgroup$– SaibooguJan 11, 2018 at 20:23
They are part of the TEL that is used to hold the fairing for extra stability while in transit. You can see the almost identical fittings on the LC-40 TEL from the Zuma mission, Jan 7, 2017.
You can see below it there is a set of arms or maybe a collar that is holding the top of the stage as well. These open before launch, but also help hold the stage to the TEL as it rolls from the HIF to the launch pad. The ones higher up are just for additional support of the fairing.