This weekend, SpaceX successfully passed a big milestone in the development of its next-generation deep-space rocket called Starship, which is designed to one day send cargo and people to the Moon and Mars. Overnight on Sunday, a prototype of the rocket underwent a super cold pressure test in Texas and remained intact on the test stand, paving the way for this particular vehicle to fly to a low altitude in the upcoming weeks.

this same test has destroyed other Starship prototypes in the past

Passing this test is a major step for SpaceX since this same test has destroyed other Starship prototypes in the past. Known as a cryogenic proof test, it entails filling the vehicle with incredibly cold liquid nitrogen to see if the vehicle can handle the same types of temperatures and pressure it’ll have to deal with when it’s filled with super cold propellants for launches. SpaceX lost three previous vehicles during these cold pressure tests; the prototypes either burst apart or imploded while on the test stand at SpaceX’s facility in Boca Chica, Texas. SpaceX CEO Elon Musk said that this test was a bit of a “softball” pressure test, but it was enough to proceed with flight tests.

SN4 passed cryo proof! pic.twitter.com/EJakThZRGF — Elon Musk (@elonmusk) April 27, 2020

Engineers will install SpaceX’s newly developed Raptor engine onto the base of the prototype this week. The company will then ignite the Raptor while restraining the vehicle to see if the engine is working properly. SpaceX developed the Raptor engine specifically for Starship, and the final design of the rocket calls for six of these engines to power the vehicle. But SpaceX will only use one Raptor on this prototype, with plans to increase that number on future vehicles. The next prototype will get three Raptor engines, according to Musk.

Once the Raptor is tested properly on this prototype, it’ll be time for this vehicle to catch some air. SpaceX intends to fly the prototype up to an altitude of 492 feet, or 150 meters, and then land it back down on the ground in one piece. It’d be a short “hop” test, meant to test the vehicle’s ability to take off and then use its engine to touch down gently afterward. This type of propulsive landing is how SpaceX lands its Falcon 9 rockets after launch, and it’s the same technique that the Starship is supposed to use when it lands back on Earth after launch or when it lands on other worlds — such as the Moon or Mars.

Musk claims everything should be “physically ready” for the hop test in a few weeks

SpaceX conducted a similar hop test back in August with a very early prototype of Starship called Starhopper. That vehicle did not resemble the final design of Starship, looking more like a water tower with landing legs. But this new prototype should be more similar in size and shape to Starship when it flies, though it’ll still be missing some hardware that the final design will have. Musk claims everything should be “physically ready” for the hop test in a few weeks, but regulatory approvals from the Federal Aviation Administration “may take longer.”

Meanwhile, SpaceX is still updating the design of Starship and implementing changes on future vehicles. Production of the next Starship prototype is already underway as the company continues to develop this rocket at a rapid pace in Boca Chica.