Blue Origin, the US private space launch company, has successfully test fired the world’s most powerful methane-burning rocket engine. Rockets such as this, fuelled by natural gas, will be essential for the first crewed missions to Mars.

The company, founded in 2000 by Amazon’s chief, Jeff Bezos, released a video on 19 October showing a six-second firing of the BE-4 engine at its suborbital launch facility near Van Horn, west Texas.

Running on liquefied methane mixed with liquid oxygen, the engine will produce 250,000kg (550,000lb) of thrust at sea level – nearly 50% more than a Space Shuttle main engine. Methane is more dense than the liquid hydrogen which powered the shuttle, so fuel tanks can be smaller and lighter.

The news is pivotal in the race to put people on Mars – or rather, to get them home again. One of the headaches facing mission designers is how to carry the enormous mass of fuel needed for the return journey. But methane could be manufactured in-situ from chemicals in the atmosphere of Mars.

Seven BE-4s will make up the first stage of Blue Origin’s forthcoming New Glenn orbital rocket, scheduled for its debut flight in 2020. The revolutionary engine is also being considered by the United Launch Alliance – a consortium of US space hardware firms – for the Vulcan heavy-lift satellite launcher, due in 2019.

Blue Origin’s announcement coincided, the same day, with the news that the US air force was adding $40m to an existing contract with the launch firm SpaceX to support development of its methane-burning rocket engine, the Raptor. SpaceX has its own designs on Mars, aiming to send people there by 2024.