SpaceX loses the center core of its Falcon Heavy rocket due to choppy seas

SpaceX successfully landed the center core of its Falcon Heavy rocket on a drone ship last week, but the vehicle accidentally fell into the ocean while in transit to the Florida coast. The company blamed the loss on choppy seas.

“Over the weekend, due to rough sea conditions, SpaceX’s recovery team was unable to secure the center core booster for its return trip to Port Canaveral,” SpaceX said in a statement to The Verge. “As conditions worsened with eight to ten foot swells, the booster began to shift and ultimately was unable to remain upright. While we had hoped to bring the booster back intact, the safety of our team always takes precedence. We do not expect future missions to be impacted.”

The center core is a modified Falcon 9 booster — one of three that make up the Falcon Heavy rocket. This particular core flew on Thursday, April 11th, from Cape Canaveral, Florida, during the second flight of the Falcon Heavy. The flight marked the first time the rocket had flown in over a year since its debut in February 2018, as well as the first commercial mission for the vehicle.

Following takeoff, all three cores of the rocket successfully landed back on Earth: the two outer cores touched down on dual concrete landing pads at the Cape while the center core touched down on the company’s drone ship named Of Course I Still Love You in the Atlantic. It was the first time that SpaceX had pulled off a triple landing. During the Falcon Heavy’s first flight, the outer cores landed just fine, but the center core missed the drone ship entirely and slammed into the ocean.

Now it seems that the ocean once again got the better of the Falcon Heavy center core. SpaceX does have ways to secure the rockets it lands on drone ships, including a robot known as the “octagrabber” that latches on to the base of the boosters. But because the center core connects to two side boosters, it has a different design than a normal Falcon 9 booster. So the octagrabber cannot hold on to it in the same way.

Apparently, SpaceX’s octagrabber just needs some upgrades so that it can nab the center core, according to SpaceX CEO Elon Musk. On Twitter, he noted that these attachments were not ready in time for last week’s landing. In the meantime, he noted that SpaceX may be able to save the engines of the core, though there was no mention of the rest of the booster.

Whenever SpaceX launches the Falcon Heavy, at least one booster does need to land on a drone ship, as the company only has two concrete landing pads at the Cape. The center core is usually the best candidate for an ocean landing, as it travels farther into space than the outer boosters. That eats up fuel needed to return to Earth and land. Plus, landing on solid ground requires more fuel than targeting the drone ship, which can position itself downrange of a returning booster, like an outfielder fielding a fly ball.

SpaceX has another Falcon Heavy mission coming up sometime this summer in Florida, one that will use an entirely new center core and the two outer cores that landed last week. The company plans to use the octagrabber during the mission, so there is some time to do updates so the robot can hold onto the center core. And perhaps calmer seas will be more conducive to transporting rockets.

Updated April 16th, 10:00AM ET: This article was updated to include more information from Elon Musk, as well as clarify how SpaceX lands its rockets.

Comments

Ah damn that’s a shame. They made the correct call but would have been nice to bring that home for analysis. See what stresses were obtain due to being the core of the three boosters etc. Hopefully they don’t encounter this on their next launch.

I was wondering how the booster was secured to the drone ship during transport back to shore. I thought maybe there were other manned support ships whose crews boarded the drone to secure the booster. Seems like a very unstable load in rough weather.

They need to talk to Boston Dynamics and get some robot crewmen on deck to bolt that thing down

The Boston Dynamics robots will likely fall in the ocean themselves.

Then we need to talk to iRobot and get some rovers to keep the Boston Dynamics robots from falling over.

The rovers will just sail around the oceans in random patterns until it decides it’s explored.

They already have a roomba like big robot: Octagrabber. However since design of this core is different from normal Falcon 9’s, its modification was still not complete. So it was not used this time.

Presumably it’s mostly hollow; did it sink? If not, could they salvage and analyze it, even if it’s no longer space-worthy?

A tube is stiff in one direction but weak in every other.

That’s what she sa….

From what I heard, they are bringing it back horizontally after it fell. Probably with some damage.

They probably have to, can’t leave an intact booster core out in the open just like that after all.

It seems like the landing pods should include a hydraulic system to allow a controlled rotation to lay horizontally and lower its extremely high center of gravity. Maybe that’s what they mean when they say it won’t be a problem in the future.

The comment was regarding the impact of this event on future missions.

We do not expect future missions to be impacted

They could also avoid this particular risk by scrapping the sea landings in favour of dry land, but I assume that would bring other issues I’m not familiar with into play.

More fuel would be required to return to land, which means a heavier rocket, which means not as much deliverable payload or as high.

They aren’t landing boosters at sea just for fun. There are situations in which it is impractical or impossible — owing to velocity and fuel considerations — to boost back to land. The center booster continued to burn after the side boosters had shut down, and so was farther down range and going faster.

Thanks, that makes sense. I assumed there was a good reason for the sea landings, but didn’t know what that would be.

Any system to rotate the booster would have to be ground based, since otherwise it would eat into an already limited payload capacity. Also, the center of gravity is pretty low due to all the engines being at the bottom. However, the booster body DOES act like a big wind sail. Combine that with a rocking boat and lack of proper anchoring and that booster’s gone.

Can probably salvage engines and other bits.
Say…whatever happened to that snappy little Roomba deal that was suppose to run out and tie down the booster? Not reliable enough?

They address it near the end of the article. Apparently it’s designed for the normal F9 and not this upgraded one.

There’s only so much a 10 story building can take with that kind of swaying

As soon as it landed I thought about this exact scenario.

The center of gravity is too high especially with rough water. Which they have zero control over.

They need some special way to secure the rocket to the deck or change the design of the drone ship

They do have a way to do that, but not with a center booster modified for a Falcon Heavy — or, they didn’t this time.

This seems to be… not a great system they have for recovering that center core. You could argue they’re getting closer, but close only counts in horseshoes and hand grenades. It’s not like this is going to be the last time they’re going to need to deal with choppy seas. The ocean is rarely a sheet of glass.

Have they had any successful recoveries from the drone ship? They seem to be spending more on trying and failing to recover boosters that way than just letting them fall in the ocean on their own.

View All Comments
Back to top ↑