Amazon chief executive Jeff Bezos has unveiled the rocket engine that will power his space company's giant spacecraft to take people and satellites into orbit.
Alongside running Amazon, Bezos has a space company called Blue Origin which competes with billionaire rival Elon Musk's SpaceX.
On Monday, Bezos tweeted a picture of the BE-4 rocket engine which has been under development for four years. It is now complete and will be used to power the New Glenn rocket, a giant spacecraft that will carry astronauts and payloads to low-Earth orbit destinations and beyond.
Bezos tweeted another picture of the BE-4 engine being transported but did not say where it was being taken. Blue Origin has a test site in West Texas.
Seven BE 4 engines will be required to power one New Glenn rocket, which will be 23 feet in diameter and be as high as 313 feet, depending on the payload. Bezos wants to fly the rocket before the end of the decade.
Like SpaceX, Blue Origin has been working on reusable rockets that land after takeoff. Bezos' company has already tested this technology with its New Shepard rocket which can perform a vertical takeoff and landing. The advantage is that it cuts the cost of space travel. The New Shepard is a sub-orbital spacecraft, meaning it is does not go as high or fast as the New Glenn. Re-landing the New Glenn would be a massive feat.
Blue Origin is also working with the United Launch Alliance (ULA), a joint venture between Lockheed Martin and Boeing to provide launch services for the U.S. government. The ULA is building a new rocket called Vulcan which will employ the BE-4 engines.