Elon Musk’s SpaceX successfully landed its Starship test vehicle unscathed on the fifth attempt on Wednesday, advancing efforts to prepare it for future flights and landings on the moon and Mars.

The uncrewed 16-story rocket ship was launched from the company’s facility in southern Texas and landed back on its pad after a six-minute flight, climbing as high as 10 kilometers (6.2 miles). A small fire broke out at the base of the rocket after landing, but was extinguished after a few minutes.

The mission continues a frenetic period of launches by closely held SpaceX for government, military and commercial customers in recent weeks, including the successful transit of astronauts to and from the International Space Station.

The experimental Starship design underpins the recent $2.9 billion NASA contract win by SpaceX to provide a lunar lander for astronauts later in the decade. The two losing bidders, Jeff Bezos’s Blue Origin LLC and Leidos Holdings Inc., filed official protests over the award which they said was driven in part by lack of funding to hire more than one contractor.

Previous SpaceX efforts since the first Starship flight last December ended with the loss of the vehicle, highlighting the complexity of the mission, which includes flipping the vehicle upright from a nose-down position before touchdown.