SpaceX F9 : Starlink 5 (v1.0 L4) : Feb. 17, 2020 : Master Thread

[FutureSpaceTourist]

With nothing brought back to any port, it seems B1056 was scuttled at sea

https://twitter.com/spacexfleet/status/1231559769527377921

We have a photo of Commander and our answer. The deck is completely empty.

B1056 was scuttled at sea.

A massive thanks to @ASOGDroneship (lol) for sending me this photo.

[SteveU]

Is there any other video than the SX live feed? Are we sure the splash was gentle and right next to OCISLY?

If the propellant for the landing burn was marginal, it's possible that the booster's "soft landing" wasn't quite soft enough and the splash we saw started farther from the barge than everyone thinks....

No, what we see is all the live feed. Since SES-10 SpaceX stopped releasing the audio visual images from 3 different angles they have on the droneship. They don't seem too keen on releasing footage people want like that from BulgariaSat-1.

Back to topic (sarc font too hard to read)

Based on OCISLY’s video the seas in LZ didn’t seem too rough, but, we are looking at a failed landing by a booster and two badly damaged fairing halfs from the same launch. Could there have been issues like sever upper level winds or sheer that could have affected all three? Caused the booster to use extra fuel or other consumables and also played havoc with the fairings or chutes?

(Out of curiosity- are they still using an open circuit for the grid-fin hydraulics?)

No, no way wind can cause that damage to fairings. It's 99% likely that the parachute got caught in the net, the fairings detached and hit the deck. This is likely because there was a parachute in Ms Tree net.
And it's not like winds blew them off course and land 500metres away like on Iridium-6, they clearly were within 1 metre or so.

And grid fins use the closed circuit with valves to stop stalls. B1056 would've been one of the first new boosters to get the upgraded system. Open circuit hydraulics were a problem on CRS-5 but they didn't make them closed-circuit till quite after, they just chucked more fluid in.


Why did it fail then? We might not know for weeks months or years, SpaceX clearly is embarrassed and think it's bad PR to say why it failed, otherwise they would've shown footage and Elon done a quick Twitter Q&A as they've done for every other landing failure.

Thanks for the reply. Been wondering about the hydraulics for a while.

[DistantTemple]

Or they just don‘t know (yet) what failed during landing. For example, if it was a software bug that isn‘t reproduceable, they might be still evaluating the whole thing. Sometimes software behaves strange. And I can think of several more things, that might only give hints about the cause but no clear proof, so that might be the reason about the silence.

Historically though Elon will acknowledge the failure within 1 hour, say they're working on getting video. Within 1 day they have video, release it and Elon says what they know. Heck on Jason-3 they were saying they thought it was a hard landing during the webcast even though that was wrong.
Elon hasn't even acknowledged or even liked a tweet acknowledging it failed.

In the general press speculation and (negative) comment has stopped, nothing to see, all moved on. Unfortunately if EM tells us what went wrong, it would likely start a new round of "SpaceX failled, landing..." etc. There is thus pressure for Elon to shut up, and not say/tweet a word. However Elon, please don't! We would like to know!

[capoman]

I doubt SpaceX is embarrassed about this. You’ve seen their fail video haven’t you? They consider every failure a learning experience, and I’m sure they are in the process of learning something new. The silence is again likely due to ongoing investigation, and I’m sure it’s only because the reason for the landing failure is not obvious.

[Mandella]

Or.... they know internally, but this is the kind of information that normally comes out when one particular guy gets chatty on Twitter (rather than an official SpaceX release). Lately that guy has been all-in on Starship and maybe this just wasn't the top thing he was excited to tweet about. It doesn't need a more complicated explanation than that.

Perhaps someone can get in a question about it at the CRS presser next week.

Really hoping some certain YouTuber or some certain NSF reporter goes in and asks for the reason and also video. Video from onboard or different droneship camera is most interesting for me.

IIRC some details of the grid fin failure that resulted in the water abort were not revealed until someone (Tim Dodd? It was probably Tim Dodd) asked about them. As I'm sure we've all noticed Musk tends to answer direct questions directly.

For what it's worth, I would be very surprised if they have not already gotten NASA into the loop on this one. Sure, landing the booster "has nothing to do with" launching Crew Dragon, except that it totally does, and NASA will want to make sure that however the booster failed can and will not effect the safety of the crew.

[Mandella]

Is there any other video than the SX live feed? Are we sure the splash was gentle and right next to OCISLY?

If the propellant for the landing burn was marginal, it's possible that the booster's "soft landing" wasn't quite soft enough and the splash we saw started farther from the barge than everyone thinks....

No, what we see is all the live feed. Since SES-10 SpaceX stopped releasing the audio visual images from 3 different angles they have on the droneship. They don't seem too keen on releasing footage people want like that from BulgariaSat-1.

Would be nice if they would release more of the 360 videos like this:



That is one of my favorites out there.  Really works nice on a cell phone when you can change viewing angle by just moving the phone.

That is a nice clip to watch in 3D VR too, if you like to feel *right there* as a fifteen story tall rocket lands right nest to you...

 

[Vettedrmr]

For what it's worth, I would be very surprised if they have not already gotten NASA into the loop on this one. Sure, landing the booster "has nothing to do with" launching Crew Dragon, except that it totally does, and NASA will want to make sure that however the booster failed can and will not effect the safety of the crew.

How?  Since NASA has stated that booster recovery performance is irrelevant for cargo deliveries, and has stated nothing to the contrary for HSF, how does a booster recovery failure have ANYTHING to do with delivery of either cargo or crew Dragons?

[Mandella]

For what it's worth, I would be very surprised if they have not already gotten NASA into the loop on this one. Sure, landing the booster "has nothing to do with" launching Crew Dragon, except that it totally does, and NASA will want to make sure that however the booster failed can and will not effect the safety of the crew.

How?  Since NASA has stated that booster recovery performance is irrelevant for cargo deliveries, and has stated nothing to the contrary for HSF, how does a booster recovery failure have ANYTHING to do with delivery of either cargo or crew Dragons?

Engine issues or control, which could also fail on the way up. Structural issues, which could also fail on the way up. Fuel leaks resulting in faster than normal fuel use, which could also effect things on the way up. And of course the dreaded "safety culture" issue, where if there was a simple mistake in entering a correct value that raises the question of why that input was not properly checked, and was that a symptom of a general process failure. HSF raises the stakes way above cargo.

There is no way you can separate all the landing functions of a rocket from the launching functions. It would be entirely reasonable for NASA to want to make sure that whatever failed was actually limited to the admittedly non-redundant landing side and could not effect the launch, and also entirely reasonable for SpaceX to make sure they get updated quickly to stave off any concern.

Really all I am saying is that I think the actual parties that need to be in the know about the incident are indeed in the know, even if that does not include space enthusiasts on the internet.

But I still think Elon will answer if straight up asked.

[Vettedrmr]

Really all I am saying is that I think the actual parties that need to be in the know about the incident are indeed in the know, even if that does not include space enthusiasts on the internet.

Agreed.  I will say that NASA many times offers support for accident/incident investigation and analysis, regardless of their "skin in the game".  Since we don't know anything other than it landed near the barge at a low rate of speed, and we know that the landing sequence has the ballistic landing point just offset from the barge, it implies to me that there was some kind of failure that the system identified as un-recoverable.

Since the booster apparently made a controlled landing, my guess is something to do with the landing legs.  But in the absence of info it's just a guess.

Have a good one,
Mike

[Johnnyhinbos]

Really all I am saying is that I think the actual parties that need to be in the know about the incident are indeed in the know, even if that does not include space enthusiasts on the internet.

Agreed.  I will say that NASA many times offers support for accident/incident investigation and analysis, regardless of their "skin in the game".  Since we don't know anything other than it landed near the barge at a low rate of speed, and we know that the landing sequence has the ballistic landing point just offset from the barge, it implies to me that there was some kind of failure that the system identified as un-recoverable.

Since the booster apparently made a controlled landing, my guess is something to do with the landing legs.  But in the absence of info it's just a guess.

Have a good one,
Mike

Or, it's possible that the ASDS had parked at the wrong coordinates. Transposing digits on the fraction part of a lat or lon will still place the vessel in the wrong place... Reiterating for a friend, because, you know, it's not just the booster that has to work properly...

[jhersh]

I had a similar thought. Maybe the booster worked fine, but the boat was in the wrong place. Wasn't there some talk a few months ago about JRTI being upgraded with more powerful thrusters, that might be needed to hold position in the Gulf Stream? Or am I remembering this wrong?

[Vettedrmr]

Or, it's possible that the ASDS had parked at the wrong coordinates. Transposing digits on the fraction part of a lat or lon will still place the vessel in the wrong place... Reiterating for a friend, because, you know, it's not just the booster that has to work properly...

I just don't think that an entry error like that (which usually the same input is used for both vehicles) would end up with such a small error.  It's not impossible, it just doesn't seem feasible to me.

Hopefully we'll learn someday.

Have a good one,
Mike

[Jcc]

Since the booster apparently made a controlled landing, my guess is something to do with the landing legs.  But in the absence of info it's just a guess.

Have a good one,
Mike

I don’t think it was the landing legs, because those usually deploy close to touchdown when the F9 has already been directed to the landing point. We heard a call out for landing legs deploy, when that happened, the F9 was 100m or so off target, we assume because it was directed there by the program, which calculated that a successful landing on the ASDS was not possible.

[Herb Schaltegger]

To the extent we ever get a formal answer from Elon or Ms. Shotwell about this landing failure, my guess will be a sensor error or ambiguity that gave the landing logic enough reason to abort the divert maneuver; e.g., some critical sensor dropped out or gave an out-of-family reading fairly late in descent and the stage decided not to divert to the barge. Then the data turned out to have been incorrect and the stage soft-landed in the water instead.

[Comga]

Or, it's possible that the ASDS had parked at the wrong coordinates. Transposing digits on the fraction part of a lat or lon will still place the vessel in the wrong place... Reiterating for a friend, because, you know, it's not just the booster that has to work properly...

This is not that old classic Star Trek episode where switching a digit brings down Kirk in the fake Enterprise.
This is unlikely to be the Starliner parachute where one person said they entered identical numbers by hand and no one checked the records. (It’s undoubtedly automated.)
We will learn the cause if and when Musk chooses.
Speculating based on a partially seen splash is fun, and Herb may be right, but not really reliable.
 

[WannaWalnetto]

Whatever caused the booster to not divert to OCISLY doesn’t seem to be a big issue, as SpaceX has two launches / landings currently scheduled within the next two weeks.  One of them includes another barge landing.

[marokrile]

Any conclusion?

[Rondaz]

The Falcon 9 second stage from the most recent Starlink launch reentered at 1344 UTC Mar 5 over the NE Pacific, 1000 km west of Portland, Oregon

https://twitter.com/planet4589/status/1235989732531855364

[FutureSpaceTourist]

Starlink v1 launch 4 booster diverted to not land on drone ship because winds were different from predicted. SpaceX have working on improving wind modelling.

So doesn’t sound like any technical issues and certainly nothing affecting CRS-20 mission landing.

Edit to add:

twitter.com/nextspaceflight/status/1236040847575134209

Hans: Last launch had a landing failure due to the winds that the booster encountered not being as predicted. Therefore, the booster decided to divert to a water landing to protect the droneship.

https://twitter.com/nextspaceflight/status/1236041023324897281

SpaceX has made improvements to their wind predictions since that incident.

[Norm38]

That's actually really, really good news.  It's much easier to change a firmware behavior, than to track down and fix a hardware issue, or to better understand a behavior that wasn't modeled. 

It's especially easier to fix a commanded firmware behavior, that isn't some intermittent bug. Glad to hear they're making improvements.  Maybe they can be a bit braver with the landings going forward.