Two mammoth rocket engines that helped boost Apollo astronauts to the moon have been fished out of the Atlantic.

An expedition led by Amazon CEO Jeff Bezos pulled up the engines and is headed back to Cape Canaveral, Florida, after three weeks at sea.

Bezos and NASA announced the recovery on Wednesday.

The sunken engines were part of the mighty Saturn V rocket used to fly astronauts to the moon during the 1960s and 1970s. After liftoff, they fell into the ocean as planned.

The engines are the property of NASA. The space agency congratulated Bezos on his efforts. The team planned to restore the artifacts for later display.

Bezos' space company, Blue Origins, has a NASA contract to develop a private space taxi to the International Space Station.

The engine has sat for decades at a depth of about four kilometres below the surface of the ocean. The engine has sat for decades at a depth of about four kilometres below the surface of the ocean. (Bezos Expeditions)