SpaceX has completed the first tethered jump for its Starship prototype, Elon Musk confirmed in a tweet Wednesday evening.

Called the Starhopper because it’s making limited hops to test the landing capabilities of the Starship vehicle, the tethered jump represents the first firing of a rocket engine at the company’s Boca Chica launch site.

The hops are similar to the testing that preceded the commercial development and use of SpaceX’s reusable Falcon 9 rockets. Those tests, the Grasshopper and the F9R Dev, were critical to the development of those earlier rockets in the same way that these early launches will pave the way for SpaceX’s interplanetary Starship.

The Starhopper is SpaceX’s smaller prototype for what will eventually be its Starship vehicle, which the company hopes will make its first cargo flights by 2022. Musk wants the vehicle to make its first passenger flight in 2023, when the Starship will voyage to the moon. That would be followed by a crewed Mars flight slated for 2024 and the construction of a Mars Base by 2028.

Musk first debuted the new rocket in January. And since the start of the year the company has been testing several components for the new launch vehicle. Most recently, the company tested a new heat shield design that should protect the rocket as it reenters Earth’s atmosphere.