Falcon Heavy core booster lost at sea | Hacker News Reader

Falcon Heavy core booster lost at sea

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127 pointstomsyouruncle65 comments

I kind of figured that happened when they lost the video. Still a really amazing accomplishment--the video of the boosters landing was like something out of a sci-fi movie. It's the best space launch since the first Space Shuttle in 1981.

The video feed drops like that on every droneship landing.

Do you know why that happens? This is the first time I've seen it live.

According to the SpaceX media commentary folks that were talking as it was happening, it's because "intense vibrations are interfering with the antenna".

Meanwhile, in the background, a monitor appears to be showing smoke clearing from the deck of the barge, with no booster present.

https://twitter.com/Darkphibre/status/960990105581240321

Right, because the rocket ultimately didn't land on the ship. This does not invalidate anything they said about interference.

It clearly does.

They both say Oh exactly at the moment when the smoke clears, meaning that they themselves are looking at the live feed while pretending it was lost.

Also the chances that Spacex doesn't have any other presence next to the droneship are zero. There in no reason for them to be beaming the data feed via a finicky satellite connection only.

> Also the chances that Spacex doesn't have any other presence next to the droneship are zero.

Would you keep manned boats in the area where a rocket is coming down?

They keep people in the area where rockets liftoff and land (a few kms away) and besides, they launch rockets in space, do you really think they lack the technology to, for example, send the video feed to another ship waiting at a few kms distance?

Not a manned boat, but it seems obvious that they would want to have another unmanned boat with instruments recording the landing event. This could be much smaller and thousands of meters away from the landing site so there would be very little risk of it getting inoperable by the landing rocket.

From previous crashes we know they keep observers nearby.

Besides, I am sure the rocket itself had radios that were reporting on what was going on. When they all stopped sending signals at the very point the rocket should be touching down, that was a pretty sure signal it had crashed.

They use a satellite link on the barge, and the vibrations and pressure from the landing booster almost always cause the link to drop until things calm down.

They have said in the past that it's "solveable", but it's not exactly a high priority by any means as they can always retrieve the footage when they get to the barge.

The satellite antennas used to uplink a video feed like this have a very small beamwidth (around 1° depending on antenna size and the frequency they're using), so you need to keep them pointed precisely at a specific point in the sky. They rely on a sensitive IMU (accelerometers) and fast motors to actively track the satellite while the platform moves. They're quite impressive to watch in action[1], but I'm guessing they're no match for the shock and vibe of the rocket landing.

1: https://www.youtube.com/watch?v=k79vfwUkeYk

In a press conference an hour or so ago, I think Elon mentioned that, if he had to pick one core that would experience “rapid unscheduled dissassembly”, it would have been the center one. I think he mentioned it was due to the boosters having the expensive titanium grid fins and also being reusable for future flights.

Regardless, it was absolutely wonderful to watch! I think the Youtube stream had 2,500,000 viewers at one point. I can’t wait for more footage of the launch the coming days.

The unspoken point in Musk's comment is that SpaceX doesn't actually care if they get these particular rockets back. They want to prove reusability, of course, but no matter the outcome they never plan to re-fly these cores. They will focus on the not-yet-flown Block 5 cores, and standardize on that going forward.

In this flight, the side boosters and center core were Blocks 3 and 4. So SpaceX definitely wants to recover the boosters, to perfect reusability, but they never intend to re-fly any of these boosters, so better to get back the one with the expensive and reusable titanium grid fins.

Didn't they say these boosters had already flown before?

I'm also a bit surprised the grid find are so pricey, they seem pretty small? Not that I really know how much titanium costs to buy and machine.

The side boosters were flown before, and returned to Earth today for the second time. But they won't fly again.

They measure 4 by 5 feet, so we can estimate they are probably made from a solid chunk of titanium that was at least 20 cubic feet or almost 5,000 pounds. That would be nearly $150,000 in raw material and probably another 5x that in processing (guesstimating cost per cubic inch of titanium removal).

Either that or they were specially made castings, which are similarly expensive in low volume, if not more.

Wouldn't you be able to recover most of the removed titanium, amortizing the majority of that guesstimated materials cost? Processing likely remains expensive, however.

I'd think so. They also 3D print a lot, but metal powder does seem expensive.

Printed metal has huge issues with heat, and they just switched from aluminum gridfins to titanium because of the heat. I seriously doubt that they’re usung additive techniques here.

You are also dealing with low volume fabrication which means setup and tooling costs don't amortize across many components. I wouldn't be surprised if they cost $1M each.

> Block 5 cores

Why are rocket versions specified with the word "Block"? The Saturn launchers did the same thing, but it seems like a strange word to use.

It's a term carried over from the military/aerospace field.

https://www.f35.com/about/life-cycle/software

I boggle a little at what I read there, such as "With Block 3i, 89 percent of code required for full warfighting capability is flying". That's 89%? Not 88% or 90%?

You can be sure the specs for something like the F35 run into the hundreds of thousands of pages. Tagging exactly 89% of the features as making that milestone is probably the easiest part of the work.

Back when we did Shuttle launches on ww.com 10K or so was the maximum number of viewers we ever saw. It's absolutely incredible how far video delivery over the web has come since STS-87.

Keep in mind that we got kicked off the backbone because we were using too much bandwidth and 'the internet wasn't made for video' (which is why we moved to Canada to begin with).

They aren't reusing any more of the Falcons 9s we have seen. They are switching over to Block 5 of the rocket. They wanted to keep the fins, because I think those were Block 5 fins on them.

> But the core, middle booster, which attempted to land aboard “Of Course I Still Love You,” a drone barge that SpaceX uses as a mobile, ocean-borne landing pad stationed in the Atlantic for its flights departing from Florida, wasn’t recovered.

“Of Course I Still Love You” is the name of a spacecraft in The Culture, a series of novels that inspired Elon Musk when he was young.

For anyone who has not yet read of the books from The Culture series, I highly encourage you to do so. They are an amazing - agnostic - version of what our far future selves could be. Iain M. Banks had quite the mind (no pun intended).

Yes, great books! I recommend starting with 'The Player of Games', not the first book in the series but the best. They are only loosely connected, you won't miss anything.

Agreed on starting with "Player of Games". The culture books are great, but some of them arent exactly what what you'd call accessible.

I started on 'Consider Phlebas', the first book in the series. I recommend starting with that, it's a great book, perhaps not as accessible as 'Player of Games', but more wow-factor.

While 'Excession' being the most complex to me. But gosh, how I enjoyed it.

I remember an articles from The Economist that said the same thing

I absolutely love the fact that SpaceX is so open and public about their rocket launches, however, I couldn't help but get the feeling that they were in full 'PR backlash' mode [over the core booster] when ending the live stream, and from skimming many of the instantaneous press releases.

Does anyone else think that they were overly quiet on the core booster landing on purpose, in order to minimise negative PR on the whole operation; or was it simply that they did not have enough information on what happened (seems slightly implausible to me)?

This all being said, what happened today was nothing short of magic.

Agreed, at the very end of the feed actually, the 2 presentators didn't really know what to say about the status of the core booster. A space X employee showed up (I assume a PR or an engineer previously briefed by PR, all he had was a SpaceX polo). The guy essentially said: 'best test ever, everything went smooth yadi yadi yada, oh and also, we gotta figure out about that last booster. Otherwise, everything went perfect !"

Which is very true. But it was clearly a move to divert away the audience from that last booster. Which is understandable. it'd be a shame if everyone focused on a lost booster when the everything else was nothing short of magic like you say ;)

Congrats spaceX, guys guys are magicians.

"A space X employee showed up (I assume a PR or an engineer previously briefed by PR, all he had was a SpaceX polo)"

I think you're talking about John Insprucker: https://twitter.com/jinsprucker?lang=en

He's a senior engineer who was present for the whole cast. Look at it again.

They were, but I understand. It was the last thing to happen and they didn't want THAT to be the story or the thing that sticks in people's minds. delaying it a couple hours was smart from a PR perspective.

That said I can't wait to see the video.

Yes. This was a very minor failure in comparison to the overall launch. But this lack of transparency played right into the undercurrent of sleaziness that seems to hang around Elon Musk industries.

I'm a big fan of SpaceX and of Musk as well, but he's still winning even if he fesses up to the minor setbacks.

If even a big fan thinks it, it must be very true indeed.

They definitely did go into full PR mode after they lost signal to the drone ship. But I think they did that in part because this launch had so many moving parts that if someone had just tuned in to that moment and seen a massive rocket exploding against the drone ship they may have thought that the launch had fail.

And considering that the core booster landing on the drone ship was a mere side benefit of the overall launch it was probably the best thing to do.

They are clearly in an unenviable position but I think they would have come off better with a more honest, direct acknowledgement of the failure of a tertiary objective, rather than that "oh noes, might derail the emotive hype-train, let's awkwardly pretend we don't know what happened and just hope the audience forgets", which is fairly patronizing and not particularly effective at achieving its intended goal. An awkward, ineffective cover-up is worse than just telling the truth and moving on.

They were prepared for it to RUD right there on the pad, losing one booster is pretty much one away from a flawless mission. I've been on previous live streams when an anomaly occurs, this was no different and what I come to expect — the moment they didn't cut back to a video feed it was very obvious what had happened and that they'd need time to figure it out.

Doubt any thought of 'Public Relations' went through the minds of any of the presenting engineers. Clearing the launch tower was a massive achievement, everything else was a bonus. Loved seeing the engineers all beaming at the end with John joining in — away from a desk!

they also re-uploaded the webcast video with feeds from both booster cameras, I also didn't remember seeing the fairing separation so well when watching it live

https://www.youtube.com/watch?v=bCc16uozHVE

SpaceX hasn't failed a landing of a booster in two years (correct me if I'm wrong). I hope a lot of data was collected as to why and how it failed.

SpaceX's biggest advantage is that they iterate quickly. Hopefully next iteration fixes whatever problem they had today. Those boosters aren't cheap.

Musk attributed it to low levels of triethylborane—a hot-burning propellant that essentially acts as rocket engines' starter fluid—in the center booster.

The center core is a special structurally enhanced model, so I'll give them a pass since they're flying a new bird. I'm sure they'll get it right.

That makes a lot of sense. The center core had to ignite for liftoff, then either scale back or stop entirely during the main lift phase, then re-ignite when the side boosters detached, then reignite for the boostback, entry AND landing burns. That's a lot of re-ignition!

I hope they post a very high quality video of that booster having its unplanned disassembly. May not be great for PR, etc, but it sure would be entertaining.

> Eventually, Musk hopes to be able to turn rockets around in less than 24 hours and have reflown boosters go up twice in one day.

This will be amazing.

This won't be a huge flashy milestone when it happens, but future historians will point to that achievement as an inflection point in space travel.

Remember a few short years ago when humans always threw away the rocket after every trip?

Agreed. It's the Henry Ford moving assembly line of rocket launches. It's a game changer.

I'm still impressed beyond words that they were able to glue basically 2 reused rockets onto a 3rd rocket and then not only have a successful test flight but return 2 of the 3 boosters.

Fun fact: there is a pneumatic mechanism that gives the side boosters a gently push away at the top, with the bottom attachment point separating milliseconds later. This is to cause the side boosters to fall away from the center core properly.

Yes, I remember this. Had stayed up all night to watch the launch. After the side cores landed (which was mind blowing honestly), the cameras switched to drone ship where the center booster was supposed to land. The only thing I could see was mist & fog, and they switched to their commentators 2 seconds after that. Thought I must have not noticed the successfully landed core, & went back to sleep dreaming of the cool life Musk lives.

>and in the live stream SpaceX provided of the launch, you could hear someone say “We’ve lost the core” but it wasn’t clear whether that indicated just the feed, or the booster itself.

That’s definitely not set-speak for ‘video feed’ but I wish it was.

And the article does not say / make apparent where this information is from.

There was just a press conference where he went into some detail, with the caveat that it's all still very early information.

Basically he said that 2 of the 3 engines didn't start up correctly, and caused the booster to hit the water at a few hundred miles per hour.

I'm guessing the dive into the water was purposely missing the barge when it detected the problem, as they have spoken about this capability in the past when they were first making attempts at landing the rockets.

He also said that as long as they have the footage, and it's cool looking, they will post it somewhere!

I previously thought that the middle core on a Falcon Heavy was expendable. So it not landing (while needing 3 engines) makes sense, as it was only a week or two ago that they tried a fast/hard landing with 3 engines over open water (as they weren't sure then that it would work). I would expect this landing mode to need at least a couple more tries to get working reliably.

Well that test was unrelated. They only reason they tried that with an ocean landing was because they wanted the barge for the FH demo flight.

This should have been a 1-3-1 style landing burn where it lights up one engine, then 2 more to slow it down, then drops down to just 1 again at the end. In this case it sounds like the the outer 2 engines didn't start up right, so it came in way too hot.

They also have said that the center core of FH is basically a new design from the ground up, so it makes sense that they had some problems on it's first landing.

He mentioned the centre core landing failure "took out two of the engines on the drone ship".

Musk elaborated this during the press conference. Said the core booster hit 100m from the barge at almost 500kph.

That's actually a good time to miss the barge. Fortunately the booster didn't score a barge hit at 500kph!

The booster's trajectory points to water until pretty shortly before landing. Precisely so that when things go wrong the expected result is to miss the drone ship (or landing pad).

Wonder if it would have been >100m away had all the engines failed. One engine working may have resulted in it attempting an approach?

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