Author Topic: SpaceX Falcon 9 : CRS-16 (Dragon SpX-16) : December 5, 2018 - DISCUSSION (Read 255698 times)

WithCarbos · « **Reply #100 on:** 12/05/2018 05:32 pm »

https://clips.twitch.tv/AdventurousConcernedGazelleKappaWealth

Prettz · « **Reply #101 on:** 12/05/2018 05:32 pm »

Quote from: meekGee on 12/05/2018 05:28 pm

how does a stage recover from such gyrations even?

suppose one control surface failed, and then the system recognized and adapted and .. still... the starting conditions were insane...

Really good software!

TrevorMonty · « **Reply #102 on:** 12/05/2018 05:32 pm »

Expect the odd failure it is first generation RLV. At least they have complete stage to analysis for fault, assuming it can be recovered.

OnWithTheShow · « **Reply #103 on:** 12/05/2018 05:32 pm »

It looked to me like there was more spin on the first stage all the way from stage sep. Maybe there was a non-functional thruster block

jpo234 · « **Reply #104 on:** 12/05/2018 05:33 pm »

Something got loose at T+6:02.

Lars-J · « **Reply #105 on:** 12/05/2018 05:33 pm »

Quote from: AnnK on 12/05/2018 05:31 pm

Quote from: toruonu on 12/05/2018 05:27 pm
But why cut the feed?
Quote from: toruonu on 12/05/2018 05:27 pm
But why cut the feed?

Am sure the 1st stage went out of control and crashed. Space X does not share bad news

Don't worry, we'll see it. Lots of tracking cameras (professional and amateur) at KSC.

It definitely seemed like this was a gridfin issue.

Zach Swena · « **Reply #106 on:** 12/05/2018 05:33 pm »

It looked like either a control system failure, or actuator failure on the grid fins. The top right fin in the picture seemed to be providing rotational input independently of the other fins, so I would think something wrong with the actuators, or position sensors causing a control system failure.

deruch · « **Reply #107 on:** 12/05/2018 05:33 pm »

Even during the post-separation and boost-back portion of the return it looked squirlier than normal. I'm not used to seeing fast rolls during that portion.

jak Kennedy · « **Reply #108 on:** 12/05/2018 05:34 pm »

Quote from: AC in NC on 12/05/2018 05:29 pm

That didn't look like ice that came off during descent. It looked like some kind of seal was lost from a grid fin.

It was definitely circular.

edit for clarity.

rockets4life97 · « **Reply #109 on:** 12/05/2018 05:34 pm »

No explosion in the video posted above on landing. That is impressive.

Lars-J · « **Reply #110 on:** 12/05/2018 05:34 pm »

Quote from: jak Kennedy on 12/05/2018 05:34 pm

Quote from: AC in NC on 12/05/2018 05:29 pm
That didn't look like ice that came off during descent. It looked like some kind of seal was lost from a grid fin.

It definitely circular.

It was just ice.

Halidon · « **Reply #111 on:** 12/05/2018 05:34 pm »

Quote from: matthewkantar on 12/05/2018 05:31 pm

I thought the grid fins were working pretty hard.

Just re-wound the YouTube feed, seems like about 15 seconds before they cut away. The fins barely move after the entry burn, the fin on the left of the camera shot appears to not move at all and the one on the right moves just as the "spin" begins.

whitelancer64 · « **Reply #112 on:** 12/05/2018 05:34 pm »

"Water landing"

I really wish the director of the webcast had the guts to show that.

Anything from the NASA webcast?

Pictures / videos from anyone there??

envy887 · « **Reply #113 on:** 12/05/2018 05:35 pm »

Quote from: Norm38 on 12/05/2018 05:28 pm

Crazy, that's the first failed landing since June of 2016.

The Heavy core also splashed this year

jcliving · « **Reply #114 on:** 12/05/2018 05:35 pm »

Wow! I cannot believe they had the control they did!

Lars-J · « **Reply #115 on:** 12/05/2018 05:35 pm »

Quote from: whitelancer64 on 12/05/2018 05:34 pm

"Water landing"

I really wish the director of the webcast had the guts to show that.

Anything from the NASA webcast?

Pictures / videos from anyone there??

Chill, there will be plenty of video uploaded real soon... probably as I type.

EDIT: here is a still photo before impact: https://www.instagram.com/p/BrBAqubgxAf/ The landing burn certainly worked.

OxCartMark · « **Reply #116 on:** 12/05/2018 05:36 pm »

Things went south ~5 seconds before the "stage 1 transonic" callout. Could it have something to do with that?

sghill · « **Reply #117 on:** 12/05/2018 05:37 pm »

At T+ 7:00, the booster looked like the angle was way way way off the end of the landing burn compared to previous landings (perhaps one outboard engine didn't shut down in time?). Then, at T+ 7:33, one of the gridfins was cranked all the way over and the other wasn't moving much at all as the spinning started.

It's easier to see both events if you watch the video, but here are two screen grabs.

I doubt we'll see more land touchdowns any time soon after this....

DigitalMan · « **Reply #118 on:** 12/05/2018 05:37 pm »

From those videos I would think it was at least possible to land intact but perhaps there was not enough control to safely vector over to the landing pad.

The way it was tilting and rotating perhaps the legs would have given out anyhow.

matthewkantar · « **Reply #119 on:** 12/05/2018 05:37 pm »

Last words from the SpaceX launch host before the stage diverged: "It is SO exciting along the Space Coast!"