SpaceX Falcon 9 : CRS-16 (Dragon SpX-16) : December 5, 2018 - DISCUSSION

[Lars-J]

The fin is there. There is a gash, the wall is bent. There is no bag attached to the fin.

What gash? Where is it bent? Look closer.

[stcks]

The fin is there. There is a gash, the wall is bent. There is no bag attached to the fin.

What gash? Where is it bent? Look closer.

Interstage

[ugordan]

The fin is there. There is a gash, the wall is bent. There is no bag attached to the fin.

What gash? Where is it bent? Look closer.

I remember comments after Orbcomm-OG2 landing that the tankage had to be bent and crumpled. Turned out it was just a soot pattern, but hey. This is almost as interesting to follow.

[Lars-J]

The fin is there. There is a gash, the wall is bent. There is no bag attached to the fin.

What gash? Where is it bent? Look closer.

Interstage

Sigh. I can't wait to see this thing lifted out of the water so people will see what is actually there. But then I remember all the old discussions where people insisted certain dirt streaks on the recovered booster was showing buckles in the tank. They never admitted they were wrong.

Anyway, look at BOTH images I attached a few posts ago. The gash mush come and go. It is a flotation bag with grid fin shadows on it.

[ellindsey]

Zooming in on the first picture, you can see that not only is there a large rip in the interstage, but the shadow pattern shows a bend in the interstage wall where nearly a quarter of the interstage circumference has been torn and bent slightly outwards.  The top of the interstage is no longer circular, but has an outward bend in the torn area.  This is also slightly visible in the image which shows the top of the interstage, although there the torn section is mostly submerged.  This is going to make it impossible to attach the lifting cap, even assuming they could with the rocket sideways.

[CorvusCorax]

If you zoom in on the full res images its quite clear. But the stage is rotated ( roll axis ) 90 degrees betwern the two photos showing stage from top and side.

In the too view where u can see inside the interstage the broken section is at the bottom, extending into the water.

In the side view the broken section is above the warer toeards tge viewer.

All 4 grid fins are there

[whitelancer64]

If you zoom in on the full res images its quite clear. But the stage is rotated ( roll axis ) 90 degrees betwern the two photos showing stage from top and side.

In the too view where u can see inside the interstage the broken section is at the bottom, extending into the water.

In the side view the broken section is above the warer toeards tge viewer.

All 4 grid fins are there

The stage has not rotated in the two pictures. The SpaceX / F9 logo and US flag are on top of the stage in both pictures.

[Lars-J]

If you zoom in on the full res images its quite clear. But the stage is rotated ( roll axis ) 90 degrees betwern the two photos showing stage from top and side.

In the too view where u can see inside the interstage the broken section is at the bottom, extending into the water.

In the side view the broken section is above the warer toeards tge viewer.

All 4 grid fins are there

The stage is not rotated 90 degrees. Pay attention to the where SpaceX and F9 logos are. And note that the interstage has THREE outer separation pushers at 120 degrees apart. If it was rotated 90 degrees they would not line up the same way.

I so look forward to seeing this on land.  (stcks, ellindsey, CorvusCorax, saliva_sweet)

[vanoord]

I think it's a bit optimistic to assume the leg was removed intentionally.  I suspect it was broken off either by wave action or accidentally by hitting a tugboat or tow rope.

If one of the legs had broken off, one would expect the stage to have rolled round so the lost leg was upwards.

If one leg has been removed *intentionally* to reduce the draught then that would explain the buoyancy bags, ie put them on the two horizontal legs, then drop the underwater leg off.

[stcks]

I so look forward to seeing this on land. 

What will you do when you see a real gash there Tell you what, ... loser pays for a 6-month L2 membership for someone?

[whitelancer64]

Given that we can already see that there isn't a gash, this is a very poor wager.

[1]

Wondering what kind of discussions might be going on right now for future "wet" recoveries. Can we take a page from the shuttle SRB experience?

Hypothetical. Let's say next time that a tanker gets sent out to flood the RP-1 tank with deionized water. The stage rights itself, and sinks much (most?) of the way below water. Stresses due to wave action should be reduced, and workers on the surface might have a much easier time fixing the end cap to allow crane lift right from the drink and back onto OCISLY avoiding the issue of towing altogether.

Feasible? Or am I talking about my butt more than I already realize? I'm fully aware that those people out there, with their 24 hours of experience, are now the worlds foremost experts on towing a floating rocket stage that was never intended to be towed or floated.

[ugordan]

Wondering what kind of discussions might be going on right now for future "wet" recoveries.

The "discussions" are probably like : "let's avoid them, m'kay?"

[vanoord]

IMHO, a lot is going to depend on how much they learn from this one / how much can be recovered.

I'd guess the aim will be to analyse this core to see what's been stressed the most, figure out the pump failure, *possibly* try and recover an engine to see if can be re-started and recover the grid fins and legs.

In future, I'd expect grid fin and leg recovery and not a lot else.

With the amount of out-of-parameter stress this stage has ensured, it's a useful learning exercise - but I don't see one stage ditched for every 20-30 recovered being anything than a parts scavenging exercise.

[whitelancer64]

Given that we can already see that there isn't a gash, this is a very poor wager.

This is pretty amazing. Do you see the dress as white and gold?

Looking down the barrel of the interstage there is CLEARLY no enormous gash on the side of it in the same place where there is that distorted reflection in the previous picture.

We've already established that the booster is in the same orientation in both pictures.

[Lars-J]

Given that we can already see that there isn't a gash, this is a very poor wager.

This is pretty amazing. Do you see the dress as white and gold?

Are you suggesting that the gash will appear and disappear depending on light conditions?

[flyright]

Carnival Liberty is outbound and will likely be passing a mile or two from the booster recovery operation. Maybe there will be some fans on board with good lenses. 

[saliva_sweet]

Looking down the barrel of the interstage there is CLEARLY no enormous gash on the side of it in the same place where there is that distorted reflection in the previous picture.

We've already established that the booster is in the same orientation in both pictures.

The booster is unquestionably in the same orientation.

Are you suggesting that the gash will appear and disappear depending on light conditions?

I think it's another mystery of human perception. I am absolutely certain there is a large gash. Probably the broken flap is moving with waves so it's less visible from the top view. But deformation of the left side is visible from that view as well as the border of the gash on the bottom.

[Lars-J]

Great tracking video of the landing - and this shot catches the severe tumble a few seconds after the braking burn. 

[whitelancer64]

Looking down the barrel of the interstage there is CLEARLY no enormous gash on the side of it in the same place where there is that distorted reflection in the previous picture.

We've already established that the booster is in the same orientation in both pictures.

The booster is unquestionably in the same orientation.

Are you suggesting that the gash will appear and disappear depending on light conditions?

I think it's another mystery of human perception. I am absolutely certain there is a large gash. Probably the broken flap is moving with waves so it's less visible from the top view. But deformation of the left side is visible from that view as well as the border of the gash on the bottom.

Where's the "flap" in the 1st picture?