SpaceX Falcon 9 FT - ORBCOMM-2 - Dec. 21, 2015 (Return To Flight) DISCUSSION

[ugordan]

That's bound to strain the pad hold-downs more than usual given that without the 2nd stage, the T/W will increase to over 1.65-ish.

[DanseMacabre]

That's bound to strain the pad hold-downs more than usual given that without the 2nd stage, the T/W will increase to over 1.65-ish.

Normal static fires are executed w/o payload mated. (See Jason-3 SF for an example)

EDIT: Taken on Kim's correction.

That means you still have a point, ugordan.

[Kim Keller]

That's bound to strain the pad hold-downs more than usual given that without the 2nd stage, the T/W will increase to over 1.65-ish.

Normal static fires are executed w/o 2nd stage mated. (See Jason-3 SF for an example)

Incorrect. Static fire is done with S1 & 2 mated, but no payload.

[wannamoonbase]

S1 from F9-21 is now vertical on SLC-40. It was placed there by a large crane, which is still attached as I write this. Rumor is there will be a static fire attempt Thursday.

Was S1 from F9-21 back inside the HIF or was it taken directly to the pad. 

The use of a crane would seem to indicate the SLC-40 transporter erector is gainfully employed with the SES-9 booster.

[Craftyatom]

That's bound to strain the pad hold-downs more than usual given that without the 2nd stage, the T/W will increase to over 1.65-ish.

Normal static fires are executed w/o 2nd stage mated. (See Jason-3 SF for an example)

Incorrect. Static fire is done with S1 & 2 mated, but no payload.

Though OG2 had the payload attached for static fire, didn't it?  Thought that particular aspect depended on the launch customer's preferences.

[Ben the Space Brit]

S1 from F9-21 is now vertical on SLC-40. It was placed there by a large crane, which is still attached as I write this. Rumor is there will be a static fire attempt Thursday.

This is probably indicative of something wrong at LC39A, maybe the hold-down clamps, the strong-back or prop feeds.

[Kim Keller]

Though OG2 had the payload attached for static fire, didn't it?  Thought that particular aspect depended on the launch customer's preferences.

Yeah, I've seen them done both ways, now that you mention it.

[Kim Keller]

S1 from F9-21 is now vertical on SLC-40. It was placed there by a large crane, which is still attached as I write this. Rumor is there will be a static fire attempt Thursday.

Was S1 from F9-21 back inside the HIF or was it taken directly to the pad. 

The use of a crane would seem to indicate the SLC-40 transporter erector is gainfully employed with the SES-9 booster.

The holddowns are part of the TE.

[ugordan]

The use of a crane would seem to indicate the SLC-40 transporter erector is gainfully employed with the SES-9 booster.

The launch mount is part of the T/E and is the part the booster mounts to. Since the OG2 booster is obviously connected to the launch mount now,  the rest of the erector is pretty useless for SES-9 booster purposes. At most, they could be refurbishing it after the launch damage.

Edit: drat, ninja'd by Kim

[Ben the Space Brit]

Unless there is a redundant hold-down & core prop feed unit to be installed onto the T/E in the event of launch damage. Just move it into place with a crane and then attach the core on top of it. The rest of the erector arm is only needed to provide umbilical services to the second stage and payload if you have a crane to move the vehicle on and off the pad.

Anyone been watching SLC-40? Has there been a lot of activity at the pad, especially with cranes?

[Ohsin]

Found on Instagram posted 20hrs ago by user sunrisesurfer2

https://www.instagram.com/p/BAc5TtDBM8e/

#falcon9 on the way for another #staticfire test on Thursday after a successful landing after last launch.

[Kim Keller]

Unless there is a redundant hold-down & core prop feed unit to be installed onto the T/E in the event of launch damage. Just move it into place with a crane and then attach the core on top of it. The rest of the erector arm is only needed to provide umbilical services to the second stage and payload if you have a crane to move the vehicle on and off the pad.

Anyone been watching SLC-40? Has there been a lot of activity at the pad, especially with cranes?

Crane showed up yesterday. I haven't driven past the pad in a long time.

[abaddon]

I've got it - they will use the SES-9 S2 for the static fire attempt of the Orbcomm2 returned booster.  S2 doesn't really do much other than get fueled up and sit there so this would be a minor risk.

Yeah, probably not, but it's more plausible than SES-9 launching on the Orbcomm2 booster .

[Kim Keller]

I've got it - they will use the SES-9 S2 for the static fire attempt of the Orbcomm2 returned booster.  S2 doesn't really do much other than get fueled up and sit there so this would be a minor risk.

Yeah, probably not, but it's more plausible than SES-9 launching on the Orbcomm2 booster .

If they were going to use F9-22's S2 it would already be mated. Using this S1 for SES-9 is not going to happen - there's too much risk at this point in SX's reusability project.

[cscott]

Wow.  Curiouser and curiouser.  They do seem to be in a big hurry to get this static fire under their belts.  Perhaps LC40's HIF really doesn't have space for two cores, so the Orbcomm core had to go straight to the pad. I do wonder if they've borrowed the launch mount from LC39 or borrowed the one from the SES TE in the LC40 HIF.

If I had to guess, I'd say this is a combination of an unexpected failure or delay in the LC39 readiness (maybe as simple as not being able to get prop delivered on time, as speculated above) *combined* with some orthogonal reason why doing the test on LC40 lets them learn more than just waiting for the LC39 situation to resolve.  Perhaps testing against known-good facilities at LC40 lets them narrow down the blame for an intermittent failure, or they want to evaluate structure warping (as speculated above), something like that.  So they took the opportunity to turn lemons (LC39 delay) into lemonade (LC40 test campaign) if they moved really really fast to use the small schedule gap before the SES launch.

(And they probably have backend pressure from the Falcon Heavy campaign wanting to use all three bays of LC39, so they'd prefer not to induce delays in the FH debut by waiting around.)

[Kim Keller]

Wow.  Curiouser and curiouser.  They do seem to be in a big hurry to get this static fire under their belts.  Perhaps LC40's HIF really doesn't have space for two cores, so the Orbcomm core had to go straight to the pad. I do wonder if they've borrowed the launch mount from LC39 or borrowed the one from the SES TE in the LC40 HIF.

There's no need to borrow TE's - the SES-9 vehicle probably wasn't on the T/E yet. The vehicle isn't placed on the TE until S1/2 integration and test is complete.

[Herb Schaltegger]

Wow.  Curiouser and curiouser.  They do seem to be in a big hurry to get this static fire under their belts.  Perhaps LC40's HIF really doesn't have space for two cores, so the Orbcomm core had to go straight to the pad. I do wonder if they've borrowed the launch mount from LC39 or borrowed the one from the SES TE in the LC40 HIF.

There's no need to borrow T/E's - the SES-9 vehicle probably wasn't on the T/E yet. The vehicle isn't placed on the T/E until S1/2 integration and test is complete.

So Kim - what is the stage mounted to at the pad? Why not use the T/E if the one at LC-40 isn't occupied yet?

[ugordan]

There's no need to borrow T/E's - the SES-9 vehicle probably wasn't on the T/E yet. The vehicle isn't placed on the T/E until S1/2 integration and test is complete.

Hell, is there even a way for the OG2 booster to get to the pad than through the hangar - which doesn't appear to have room for 2 cores either way - if SES-9 was already there?

Doesn't look that way to me.

[ugordan]

Why not use the T/E if the one at LC-40 isn't occupied yet?

People here are claiming the T/E and the launch mount have been separated when the T/E could just have been lowered down to the ground at the pad. It serves no purpose erected since it grips at the top of the 2nd stage.

[Kim Keller]

So Kim - what is the stage mounted to at the pad? Why not use the T/E if the one at LC-40 isn't occupied yet?

Not sure I understand the question....the stages are on handling fixtures prior to S1/2 mate, then the vehicle goes onto the TE. I'm saying that the SLC-40 TE is being used for the F9-21 S1. I don't know where F9-22 is in its processing flow, but I'm guessing the SLC-40 TE was empty prior to the delivery of F9-21 S1.