In the very early hours of Friday morning, a high-velocity Falcon 9 rocket landed successfully on a SpaceX droneship in the Atlantic, making history as the first such mission to do so. It was a huge moment and a signal that droneship landings may become routine. And even as this was the second time a Falcon 9 stuck the landing on a droneship, it was more impressive than the the first time, which saw a slower descent with a lower risk of failure.
First, a note on why rocket landings on droneships at sea are beneficial: They use less fuel because rockets can land closer to where they launched (and thereby more fuel can be used to go further into space, which is key for more advanced missions).
How did we get to this historic moment, though?
Here are each the attempts to land on a droneship — either Of Course I Still Love You or Just Read the Instructions — in reverse-chronological order. We’ve included one scrubbed test landing as well.
6. May 6, 2016: The First Droneship Landing from a GTO Mission
This most recent landing came after a Geostationary Transfer Orbit (GTO) mission, a much more difficult trick to pull off. The Falcon 9 had to put a satellite into orbit and thereby go further into space than it would if it was merely going to International Space Station, which is in low Earth orbit. The rocket came in hotter and faster and SpaceX wasn’t publicly hopeful about its odds. “We are not expecting a successful landing this time around,” said John Federspiel, lead mechanical design engineer at SpaceX. But Federspiel and everyone else were pleasantly surprised.
5. April 8, 2015: The First-Ever Droneship Landing
“Fifth time’s a charm,” said Kate Tice, a process improvement engineer at SpaceX and one of the webcasts hosts, as the rocket landed that day. This was the fifth try and first successful landing. The Falcon 9 carried the Dragon spacecraft into low Earth orbit, where it continued on to the ISS. (The Dragon will depart the ISS on Wednesday, May 11). It happened on a Friday afternoon and it even garnered congratulations from SpaceX client NASA and a phone call from the president.
4. March 4, 2016: “Landing Hard”
There’s been no video released of the Falcon 9 “landing hard,” in the words of SpaceX founder Elon Musk. Like the mission on May 6, the rocket was coming in very hot because it had just come a long way down after putting the SES-9 communications satellite into Geostationary Transfer Orbit.
3. January 17, 2016: A Tip-Over
This mission took place on a rainy Sunday afternoon, and Elon Musk, via his Instagram account, gave us all the visual evidence of what it looks like when a rocket lands … but then tips over because the landing gear didn’t deploy correctly. This mission sent the Jason-3 science satellite into low Earth orbit, so the rocket wasn’t coming so hot, which is why it had a good chance of landing successfully.
2. April 14, 2015: “Excess Lateral Velocity”
The Falcon 9 came down OK, but it tipped over. Said Musk later: “Looks like Falcon landed fine, but excess lateral velocity caused it to tip over post-landing.”
1. January 10, 2015: “Close, But No Cigar.”
The Falcon 9’s first attempt to land on a droneship. The first-stage booster was returning after at CRS-5 mission to the ISS. Musk explained on Twitter that the “Grid fins worked extremely well from hypersonic velocity to subsonic, but ran out of hydraulic fluid right before landing.” The caption for a video released by SpaceX simply put it this way: “Close, but no cigar. This time.”