The American SpaceX company has stacked the biggest rocket ever constructed. The vehicle's two segments – an upper-stage called Starship and a booster called Super Heavy - were connected together at the firm's Starbase R&D facility in Boca Chica, Texas.
Standing roughly 120m in height, the SpaceX rocket dwarfs any previous launch system. When it eventually lifts off, it will produce about twice the thrust of the vehicles that sent men to the Moon.
The main engines on Apollo's famous Saturn V rockets delivered some 35 meganewtons off the pad. The new SpaceX Super Heavy booster should achieve around 70 meganewtons.
Company CEO, Elon Musk, says the Starship system, once fully developed, will be more than capable of taking humans to the Moon and Mars.
The American space agency, Nasa, has already contracted SpaceX to produce a version of the Starship upper-stage that can land astronauts near the lunar south pole this decade.
The most powerful rocket currently in operation is the Falcon Heavy, also built by SpaceX. This produces 23 meganewtons of thrust at launch.