SpaceX founder Elon Musk has reported that the SpaceX Falcon rocket that landed on an ocean platform recently suffered heavy damage.

The damage happened because of the rocket’s high speed after it descended to the ocean platform following the delivery of a communications satellite into orbit, according to a Discovery News report.

SpaceX had downplayed the likelihood of successfully landing the rocket before the May 6 launch, but surprised everyone by successfully touching down for the second time in the program’s history.

The rocket took greater damage this time because it required extra speed to send the payload 22,000 miles into orbit, d to sending cargo just 250 miles to the Interntional Space Station for the first mission, so it needed to burn much more fuel than the previoius booster.

The rocket was moving at a blistering 5,220 miles per hour, or 1.5 miles per second, when it the primary stage separated from the second stage 2.5 minutes after takeoff. The rocket entered the atmosphere at Mach 5.7, and then with a half-mile left, it ignited three of the nine engines to drop from 441 mph to 134 mph in seconds. It then finally throttled down to 2.5 mph and landed softly ont he platform.

The rocket was so burnt it probably won’t fly again, but it certainly marked an important milestone in the effort to figure out how to routinely land rockets and therefore significantly drive down the cost of space travel.