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

[Semmel]

Well, I concluded that from:
- screws being visible, that are behind the cover in the other engines (edit: wrong statement, screws are visible in the top-right engine.)
- white stuff visible instead of black from the other engines. Given that everything is full of soot, thats odd
- no buckling to the outside, rather white stuff into the gap between engine and metal plate

So maybe my interpretation of burned "away" was a bit too dramatic. might be that the cover is still there, just below some burned surface.

edit: lets not overstate this. Its probably nothing serious and I am sure if it was its an easy to replace part. Not really worth a page of discussion in this thread.

[Dante80]

edit: lets not overstate this. Its probably nothing serious and I am sure if it was its an easy to replace part. Not really worth a page of discussion in this thread.

Its an interesting find, and we are nitpicking here so...

A question. The thing does not look sooty. Could that mean that the cover is actually removed for inspection and we are seeing a second cover/part of the underside?

[punder]

Could the white stuff be some consequence of the supersonic reentry burn? Assuming those are the two engines used in addition to the center, they are the only ones that made that particular group of burns (launch/boostback/reentry, but not landing).

Pardon my non-aero-engineer speculation.

[Comga]

Cross posting from Updates thread, (because discussion is not updates.....)

http://forum.nasaspaceflight.com/index.php?topic=38148.msg1469736#msg1469736

This is a great pic! I am fascinated by the stuff revealed with the raceway cover removed. It's possible it's just the exposure of the photo, but it seems pretty sooty under that cover, which is surprising.

If by "raceway cover" you mean the cowlings over the tops of the grid fin pivots, there were no cowlings on the OG2 flight.

PS  The black-cross-in-circle feature is on the left of the N2 RCS thruster cluster.  This corresponds to the "before" part of the before-and-after image, where the feature appears to have switched sides. 
"That's one less mystery!"

[oiorionsbelt]

PS  The black-cross-in-circle feature is on the left of the N2 RCS thruster cluster.  This corresponds to the "before" part of the before-and-after image, where the feature appears to have switched sides. 
"That's one less mystery!"

True, but what is the "Black-cross-in a circle feature"? The circle part appears painted in the before picture and then mysteriously shiny, as though something was unbolted and removed, in the after photo. I'm having a hard time coming up with a plausible explanation.

[Lars-J]

Cross posting from Updates thread, (because discussion is not updates.....)

http://forum.nasaspaceflight.com/index.php?topic=38148.msg1469736#msg1469736

This is a great pic! I am fascinated by the stuff revealed with the raceway cover removed. It's possible it's just the exposure of the photo, but it seems pretty sooty under that cover, which is surprising.

If by "raceway cover" you mean the cowlings over the tops of the grid fin pivots, there were no cowlings on the OG2 flight.

No, that's not the raceway. The "raceway" is the external piping that runs the length of the stage, highlighted in green in image #1, and you can see the whole length of it from the bottom to the top in image #2.

[intrepidpursuit]

Cross posting from Updates thread, (because discussion is not updates.....)

http://forum.nasaspaceflight.com/index.php?topic=38148.msg1469736#msg1469736

This is a great pic! I am fascinated by the stuff revealed with the raceway cover removed. It's possible it's just the exposure of the photo, but it seems pretty sooty under that cover, which is surprising.

If by "raceway cover" you mean the cowlings over the tops of the grid fin pivots, there were no cowlings on the OG2 flight.

No, that's not the raceway. The "raceway" is the external piping that runs the length of the stage, highlighted in green in image #1, and you can see the whole length of it from the bottom to the top in image #2.

I have seen that covering before but never really realized its scale. I always wondered where they put stuff on a rocket that has no internal compartments along it. Looks like there is plenty of room for various equipment right there in the raceway.

[CameronD]

A couple of questions from the curious:

1. How far from the center of the pad did the stage touch down?  (Presumably it landed well within the area of the deck of an ASDS.. but did it?)

2. How much propellant (RP-1 & LOX) did they have to unload?

[Rocket Science]

A couple of questions from the curious:

1. How far from the center of the pad did the stage touch down?  (Presumably it landed well within the area of the deck of an ASDS.. but did it?)

2. How much propellant (RP-1 & LOX) did they have to unload?

You be the judge...X marks the spot!

[mfck]

A close-up of the engines, post-landing...

https://twitter.com/SpaceX/status/684094378021801984

Now, that's how a USED rocket looks, Jeff...

[CaptLego]

Thanks for the notes on the image.

Question: can we tell that that cover is necessarily burned off?  Might it have been damaged somehow (supersonic turbulence, etc.) and blown off, before further blackening by soot?  Or something else entirely?

It is not burned off, it is still there.

The other "cloth" opening covers look the same towards the center engine. You can follow the crease from outer to inner side & see the same effect. (blue circles added to Semmel's red image). If it isn't a lighting artifact, I'd say it is just singed at most.

[Doesitfloat]

Could the white stuff be some consequence of the supersonic reentry burn? Assuming those are the two engines used in addition to the center, they are the only ones that made that particular group of burns (launch/boostback/reentry, but not landing).

Pardon my non-aero-engineer speculation.

Dirt from the road while being carried back to the Hanger.

[OxCartMark]

This is a great pic! I am fascinated by the stuff revealed with the raceway cover removed. It's possible it's just the exposure of the photo, but it seems pretty sooty under that cover, which is surprising.

Fascinating, I don't think we've ever seen under that cover.  Can anyone shed light on what we're looking at?  Starting with the bulkhead on the right / top end and moving left we have a large cluster of "stuff" followed by two smaller clusters of stuff followed by a long repeting sequence of equally spaced thingies.  What are these thingies and stuffs?  And, is this raceway where the detonation cord is?

___________________

I'm not seeing any burned out or missing sections in the bellows blanket where the engine passes through the engine compartment cover.  Likewise, I'm not seeing the paint drips in the nozzle.  To me it looks simply as if they cleaned up the nozzle with a scotchbrite pad in an angle grinder.  Bonus points if it was the same angle grinder that was used to cut the damaged part of the vacuum nozzle extension off in one of the previous flights.

[CameronD]

A couple of questions from the curious:

1. How far from the center of the pad did the stage touch down?  (Presumably it landed well within the area of the deck of an ASDS.. but did it?)

You be the judge...X marks the spot!

Now THAT really is awesome!!!

With precision like that, next we know the DoD will be asking if they could help them land payloads in the Middle East... 

[Jim]

With precision like that, next we know the DoD will be asking if they could help them land payloads in the Middle East... 

precision has nothing to do with it.  ICBMs can do that already.

[QuantumG]

From 200kms up??

Yes.

[llanitedave]

With precision like that, next we know the DoD will be asking if they could help them land payloads in the Middle East... 

precision has nothing to do with it.  ICBMs can do that already.

Betcha they can't do it twice!   

[AncientU]

With precision like that, next we know the DoD will be asking if they could help them land payloads in the Middle East... 

precision has nothing to do with it.  ICBMs can do that already.

Betcha they can't do it twice!   

Or RTLS

[Jim]

With precision like that, next we know the DoD will be asking if they could help them land payloads in the Middle East... 

precision has nothing to do with it.  ICBMs can do that already.

Betcha they can't do it twice!   

Don't need to, just send two

[Dante80]

Come on, lets get back on topic. ICBMs have nothing to do with it.

2. How much propellant (RP-1 & LOX) did they have to unload?

LOX and helium is vented. The amount of RP-1 they had to unload is unknown, I don't think it would be much though (the legs cannot take a very heavy landing, and there is no need for a big reserve).