SpaceX News

[Tom Ligon]

This judge is holding up his 8 card. Good landing, but a mandatory 2 point deduction for not remaining upright.

Seriously, that was right on target, no sideways motion, and then the gizmo didn't catch. Pretty close.

[Maui]

A standing problem, not a landing problem.

[paperburn1]

They are theorizing that it's ice buildup on the latching mechanism that costed to not fully engage allowing the link to collapse after landing. I guess they don't have any down and locked sensors like an aircraft landing gear. But I guess is no real point to that because it's a suicide landing anyway.

[paperburn1]

Interesting quote
“Ship landings are not needed for flexibility or to save fuel costs,” Musk posted on Twitter. “Just not physically possible to return to launch site if speed at stage separation > ~6000 km/hr (3,728 mph). With a ship, no need to zero out lateral velocity, so can stage at up to ~9000 km/h (5,592 mph).”

Strut is becoming Elon Musk's least favorite word. tank strut, leg strut,

[ladajo]

As I recall, we talked about this a while back when we were trying to understand the kinematics of getting back to the same dirt as the launch site. There was some debate about how doable it was. Here is a clear answer. It is doable up to a point. The other way is to make the loop around the ball. But I am doubtful of 1st stage kinematics to support that, to include any required lateral translation to account for launch azimuths.
The current, boost, seperate, 1st stage boost up again, decell, loop an arc back over to opposite flight path, braking, and fall back to landing is an elegant use of physics.

[ladajo]

I will also be interested to see the detailed report on the landing topple. Watching the video a few times for barge pitching, it was on a down pitch in the direction of the topple. You can see it by watching the deck relative to horizon. It also looks like the leg more buckled than folded. Also, the rocket body really appears to be flexing over early during the tip, to coincide with the pitching. I am sure they have other data not shared yet. Hmmm. Waiting for further analysis.

[Skipjack]

I will also be interested to see the detailed report on the landing topple. Watching the video a few times for barge pitching, it was on a down pitch in the direction of the topple. You can see it by watching the deck relative to horizon. It also looks like the leg more buckled than folded. Also, the rocket body really appears to be flexing over early during the tip, to coincide with the pitching. I am sure they have other data not shared yet. Hmmm. Waiting for further analysis.

The bending and flexing is said to be an optical illusion due to the wide angle lens in that camera. There are other shots from different cameras that do not show the "flexing". According to Musk, the lock that holds the landing leg was frozen by ice that formed due to the extreme fog. It would not latch into place, allowing the leg to fold back up.

[ladajo]

I buy the lensing effect. Thought about that when watching. But I have not yet seen other angles.
The leg really does not seem to fold as much as it buckles. I did see Musk's post on ice.
Detailed study report will be interesting.

[Skipjack]

Have you seen these?
Not sure if you can see those without a NSF account but talk polywell wont let me attach images of this size

[ladajo]

I used to have an NSF a long time back, but haven't been there forever.
Was there any showing the initial fail?
These are nice, thanks.

[Skipjack]

Was there any showing the initial fail?

I have not seen any. Only these. I mainly posted them because they don't seem to have that barrel- lens- distortion of the video camera. I hope that they will release more images soon.
NSF is very different from talk polywell, certainly a lot stiffer and less casual. There is a lot of good info to be found there, though.

[ladajo]

One of the reasons I stopped regular visits was a sense of pomposity pervading many discussions. I prefer more casual discourse. I get enough formality in my work.
That said, I do agree that some of the the threads have been very informative and have held posters with good access to real information.

[Tom Ligon]

They are theorizing that it's ice buildup on the latching mechanism that costed to not fully engage allowing the link to collapse after landing. I guess they don't have any down and locked sensors like an aircraft landing gear. But I guess is no real point to that because it's a suicide landing anyway.

But does a sensor help? If it didn't latch, it is going over, and a warning light just rubs it in. The time between deploying the struts and landing is pretty short, and what ya gonna do about it?

Redundant latches might work. Or latch heating. A bit of hot air down the struts could help, and there is a heat source cranking it out down at the aft end.

I'm wondering how many times I've had a tripod leg slip, or maybe a folding chair not quite latched.

[Skipjack]

IIRC most people at NSF believe that a simple heater of sorts would be the easiest solution.

[D Tibbets]

They are theorizing that it's ice buildup on the latching mechanism that costed to not fully engage allowing the link to collapse after landing. I guess they don't have any down and locked sensors like an aircraft landing gear. But I guess is no real point to that because it's a suicide landing anyway.

But does a sensor help? If it didn't latch, it is going over, and a warning light just rubs it in. The time between deploying the struts and landing is pretty short, and what ya gonna do about it?

Redundant latches might work. Or latch heating. A bit of hot air down the struts could help, and there is a heat source cranking it out down at the aft end.

I'm wondering how many times I've had a tripod leg slip, or maybe a folding chair not quite latched.

That depends. If it is a spring release that drives the locking pin/ cylinder, then it is a one shot deal. If it is an electrical solenoid with a spring return if the latch does not lock it in place might allow several firings over a couple of seconds time. The landing leg deployment might have to start 1-2 seconds earlier to allow time for this...

If ice prevents full deployment,then the pin may never line up. An increase in tolerances may help this. A Kalashnikov approach instead of an M16 approach...

Dan Tibbets