SpaceX Falcon Heavy : Arabsat 6A : LC-39A : April 11, 2019 - DISCUSSION

[ulm_atms]

So....did it topple over because of waves/rough seas or did a leg just break due to the waves/rough seas?

The way it's laying and the engine bell damage....looks like a leg broke.

[Vettedrmr]

So....did it topple over because of waves/rough seas or did a leg just break due to the waves/rough seas?

The way it's laying and the engine bell damage....looks like a leg broke.

That's actually not a bad thought.  Stage starts rocking, a crush zone gets compressed slightly, now there's a rocking motion, compressing the crush zones more and more, until something gives.

Have a good one,
Mike

[joncz]

[sfxtd]

I am thinking that the ASDS could use a rocket snare, something analogous to the capture mechanism on the CanadArm end effector, but on a large scale.

[joncz]

I am thinking that the ASDS could use a rocket snare, something analogous to the capture mechanism on the CanadArm end effector, but on a large scale.

See https://forum.nasaspaceflight.com/index.php?topic=42511.0

[Comga]

SpaceX’s Falcon Heavy center core goes overboard, Elon Musk still hopeful

Posted By: Eric Ralph in SpaceX 7 hours ago

https://www-teslarati-com.cdn.ampproject.org/v/s/www.teslarati.com/spacex-falcon-heavy-booster-overboard/amp/?fbclid=IwAR0Kn1MdlNHX84Xai05IfApw3uNTJqTaf8yYtTwcydtNCfR0sYEZY79UgJk&amp_js_v=0.1#referrer=https%3A%2F%2Fwww.google.com&amp_tf=From%20%251%24s&ampshare=https%3A%2F%2Fwww.teslarati.com%2Fspacex-falcon-heavy-booster-overboard%2F

Is that photo from last week's Heavy core or from CRS-16?
It looks awful familiar.   Something about the legs and the flotation bags.
Plus don't we have Musk's tweet that the core is on the ASDS?

Good catch Comga.  Poor reporting by teslarati.  That photo did indeed come Decembers launch:

https://forum.nasaspaceflight.com/index.php?topic=46901.msg1885417#msg1885417

This is why I stick to NSF for news.

There is a caption ‍♂️

Also a good catch

B1050 may be unsalvageable after an accidental water landing in December 2018. (Tom Cross)

Dark grey text on grey background.  Never even saw it on my phone.

[edkyle99]

44186    ARABSAT-6A   2019-021A   2006.65min   16.92deg   90133km   2510km

Can we assume this is the orbit of injection? Or already after some perigee raising by the Satellite?

Looks like some perigee raising and inclination reduction has occurred.  The original perigee was something like 327 km and the original inclination was 22.96 degrees.

 - Ed Kyle

[edzieba]

The RP-1 tank CoPVs could be to serve the leg piston pneumatics and (as it's the centre core for Heavy) the pneumatic booster separation latches and pushers. Less mass-efficient than putting more CoPVs in the LOX tank - assuming there's even room, I'd bet there are more in there already to feed the upper pushers and latches - but avoids the additional plumbing hell (and mass) of routing pressure lines all the way down the stage.

[llanitedave]

Looks like maybe five engines salvageable?

[ugordan]

Looks like maybe five engines salvageable?

Looks to me like the only engines that do not have a single dent on their nozzle are the top two and the center engine.

[Vettedrmr]

Looks like maybe five engines salvageable?

I'm thinking they're all salvageable, they'll just need to replace the bells on several of them.  Good news is that everything was shut down and probably fairly cool, and they didn't take any serious shock damage (well, other than the bells).

Of course, that's my enthusiast learned opinion (don't try to buy anything with it!) from a telephoto (albeit a great one!) shot.

Have a good one,
Mike

[OxCartMark]

Well darn. That's four rather expensive titanium grid fins (and associated plumbing) that are now resting on the bottom of the ocean.

I'll bet there's going to be a fishing expedition coming up. Its not like the titanium is going to be rusting much. They know where it happened.  They've got a fleet of fairly appropriate for the job ships with time on their hands.  Keep an eye on them ships and I'll bet some specialist deepgrabbing equipment and diver support equipment shows up on deck in the next week or two.

Do we have much of an idea where it happened?  Depth there?

[Vettedrmr]

I don't know why this is in my mind or how it got there, but 5,000 ft depth comes to mind.

[Alexphysics]

The RP-1 tank CoPVs could be to serve the leg piston pneumatics and (as it's the centre core for Heavy) the pneumatic booster separation latches and pushers. Less mass-efficient than putting more CoPVs in the LOX tank - assuming there's even room, I'd bet there are more in there already to feed the upper pushers and latches - but avoids the additional plumbing hell (and mass) of routing pressure lines all the way down the stage.

Worth noting that for use on pneumatic systems it's better if the helium (or any other gas used for that, in general) is not at cryogenic temperatures... that may give you a clue as to why there are COPV's on the RP-1 tank...

[Rocket Science]

I am thinking that the ASDS could use a rocket snare, something analogous to the capture mechanism on the CanadArm end effector, but on a large scale.

Said that myself years back post #2178... Oh well...
https://forum.nasaspaceflight.com/index.php?topic=36326.2160

[OxCartMark]

I am thinking that the ASDS could use a rocket snare, something analogous to the capture mechanism on the CanadArm end effector, but on a large scale.

Said that myself years back post #2178... Oh well...
https://forum.nasaspaceflight.com/index.php?topic=36326.2160

Don't be so proud or think its a unique thought.  The ASDS threads which went on for years were constantly bombarded with suggestions for snares, grabbers, sticky flooring, magnets, big hands, holders, cables, etc. etc. etc.  There's no suggestion in that vein that NSF hasn't seen multiple suggestions of.  The standard reaction was eye rolling because its so old and unnecessary.  But the unnecessaryness was in relation to F9 at the time because SpaceX was telling us that the CG was low relative to the leg spread.  Now with FH center core maybe there might be some mild wiggle room to consider something.  Or not.

[Pete]

We know that the FH core is not a generic Block5 Falcon, it needs different fittings and strengthening in general. This added mass is not just at the bottom with the octaweb and engines.

To what extent would this raise the center of mass of the landed booster? It seem to me that a FH core would be inherently more unstable than a standard Block5?

[woods170]

We know that the FH core is not a generic Block5 Falcon, it needs different fittings and strengthening in general. This added mass is not just at the bottom with the octaweb and engines.

To what extent would this raise the center of mass of the landed booster? It seem to me that a FH core would be inherently more unstable than a standard Block5?

Thicker tank walls, so more mass for the tanks. Which puts the center of mass higher up compared to standard F9 first stage.
Also, there is booster attachment hardware both at the bottom and the top of the FH center core. It is dependent on their respective masses and their position relative to the F9 center of mass how they affect the FH core center of mass (going up or down).

But overall I think the FH core stage center of mass is higher up the stage than it is on an F9 first stage. That in theory should make it less stable compared to an F9 first stage.

[kevinof]

North east of Bermuda? More like 5000 Meters. Least that's what it says on my chart plotter. Not sure of the exact co-ordinates but anywhere N or NE of Bermuda would take you to between 3 and 5K meters in depth.

My thinking is a leg gave way - if you have a swell coming from one direction, the ASDS will sway and always place more load on a specific leg. Repeat this enough times and with enough force and snap.

I don't know why this is in my mind or how it got there, but 5,000 ft depth comes to mind.

[Thorny]

North east of Bermuda? More like 5000 Meters. Least that's what it says on my chart plotter. Not sure of the exact co-ordinates but anywhere N or NE of Bermuda would take you to between 3 and 5K meters in depth.

It was south-southeast of Bermuda, wasn't it?