The center core that was lost is one of three that the Falcon Heavy rocket uses to boost heavier payloads into orbit.
The Falcon Heavy center core successful landed on the drone barge out in the ocean, but on the trip back to Florida the barge ran into heavy seas, and the rocket fell over and slid into the ocean abyss.
"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".
Storms that hovered over the Sunshine State appear to have stirred up the rough seas out in the Atlantic which caused the core to topple over.
The three rocket cores are fixed together during liftoff and are created to break apart after launch and guide themselves back to safe landings: The two side boosters conduct synchronized touchdowns on ground pads in Florida, while the center booster aims for an autonomous seaborne platform, called a droneship.
SpaceX is the only rocket company that safely lands boosters after launching orbital missions.
Musk tweeted Tuesday that a special robot created to batten down rocket boosters while they taxi to shore was not able to latch on to the Falcon Heavy core.
The news was first reported today by The Verge. The connections between the robot and center core aren't compatible like they would be with a standard Falcon 9 booster, but SpaceX is expected to upgrade both in the future.
All three cores successfully came back to Earth in SpaceX's first triple landing. This is the first time the company has lost a landed stage on the way back to port. The droneship has yet to return to Port Canaveral, the port next to Cape Canaveral Air Force Station in Florida where SpaceX hosts recovery operations for boosters that land at sea.
The launch on 11 April was the first commercial launch of the Falcon Heavy, but the second time the Falcon Heavy was launched since it was developed.
The Falcon 9 Heavy lifting off from the historic Pad 39A at NASA's Kennedy Space Centre.
The space company has previously re-used first-stage and second-stage rocket boosters, in addition to one of its previously flown Dragon capsules. He said SpaceX could use the fairing again on an upcoming mission.
Separately, the two fairings that housed the satellite were also recovered.
The SpaceX droneship is now on its way back from the Atlantic.