Enlarge / The B1032.2 booster is not dead yet. (credit: Elon Musk/SpaceX/Twitter)

On Wednesday evening, a couple of hours after the Falcon 9 rocket had successfully deployed a satellite into geostationary transfer orbit, SpaceX founder Elon Musk shared a rather amazing photo on Twitter. “This rocket was meant to test very high retrothrust landing in water so it didn’t hurt the droneship, but amazingly it has survived,” he wrote. “We will try to tow it back to shore.” In other words, a rocket that SpaceX had thought would be lost after it made an experimental, high-thrust landing somehow survived after hitting the ocean.

This was amazing for a couple of reasons. First of all, when the first stage of a rocket hits water after a launch, it typically explodes. (This can be seen in some of the early water landing attempts shown in a blooper reel released by the company). A rocket should not survive impact because it will rupture the relatively thin aluminum-lithium alloy tanks that separate fuel and oxidizer. These tanks are built to withstand the axial force of a vertical launch, but not a crash into the ocean.

In this case, that did not happen. Perhaps the rocket descended such that the engines and lower end of the booster were submerged, before the 40-meter tall first stage tipped over—gently. Hopefully, at some point, SpaceX will release video from the on-board camera or other assets in the Atlantic Ocean that observed the landing on Wednesday evening.