posted 12-05-2018 12:29 PM               

Please use this topic to discuss SpaceX's sixteenth Dragon cargo flight to the International Space Station under NASA's Commercial Resupply Services (CRS) contract.

posted 12-05-2018 12:29 PM               

The Falcon 9 first stage landing at LZ-1 did not go as planned and the stage made a "water landing" in the Atlantic Ocean, off the coast of Cape Canaveral. This was a new Block 5 stage.

Before the feed cut off, after the re-entry burn and before the landing burn, the first stage was shown entering a spin.

posted 12-05-2018 12:43 PM               

Grid fin hydraulic pump stalled, so Falcon landed just out to sea. Appears to be undamaged and is transmitting data. Recovery ship dispatched.

Pump is single string. Some landing systems are not redundant, as landing is considered ground safety critical, but not mission critical. Given this event, we will likely add a backup pump and lines.

We may use it for an internal SpaceX mission.

Yes, cutaway was a mistake. We will show all footage, good or bad.

posted 12-05-2018 01:38 PM               

Engines stabilized rocket spin just in time, enabling an intact landing in water! Ships en route to rescue Falcon.

Tracking shot of Falcon water landing.

posted 12-05-2018 03:53 PM               

It's good to know that in the case of anomaly the vehicle targets the ocean intentionally, rather than VAB or something. This is a full explanation.

posted 12-05-2018 10:10 PM               

SpaceX refinement of the Block 5 Falcon 9 will include a backup hydraulic system to provide system redundancy.

posted 12-05-2018 10:58 PM               

Honestly, I am little puzzled about that myself. One thing is when you put the legs down, obviously, you change the moment of inertia, so you slow the roll down and I think it could be just that.

It is a single engine burning at that time, so you can't do a lot to undo a roll. But you can stabilize the other two axes and that's what I see there. I see a stabilization of pitch and yaw, so it doesn't gyrate as wildly as it did before. So from just looking at the video, the perspective narrows to a more focused area.

So I think that is one effect. The other effect could be the landing legs — just like when you put your arms out while rotating on a chair. But like I said, I think I need to look at data or we need to investigate that in detail to make sure we cover everything.