SpaceX is preparing to test a prototype of a sleek, stainless steel spaceship that the company is developing to ferry passengers on trips to Mars.

The prototype, a small version of the huge, 100-passenger Starship now in development, could undergo its first test soon, SpaceX CEO Elon Musk tweeted on March 17. The uncrewed vehicle, called Starship Hopper, is expected to take brief “hops” during the test, lifting off “only barely,” according to Musk.

SpaceX CEO Elon Musk shared this photo of the Starship test flight rocket on Twitter on Jan. 10, 2019. Elon Musk / SpaceX via AFP – Getty Images file

Neither Musk nor the company specified a date for the test, to be conducted at the company’s launch facility near Brownsville, Texas. But a county judge told the Brownsville Herald on March 21 that he had signed an order to close roads around the area on two consecutive days so SpaceX could fuel the spaceship and “test the tank.”

Views of the rocket and launch pad are being live-streamed by SPadre.com, a site that promotes tourism in South Padre Island, a resort town that is separated from the launch facility by a narrow waterway.

SpaceX intends to use the Starship as a reusable interplanetary transportation system that will launch atop a gigantic new booster known as the Super Heavy.

Musk want to use the 100-passenger Starship to colonize Mars to avoid extinction if runaway climate change or another cataclysm renders Earth uninhabitable. He said earlier this year that the vehicle could begin flying to the Red Planet in the 2020s.

The Starship could also be used for lunar missions. In September 2018, SpaceX announced that it would take Yusaku Maezawa around the moon and back, enabling the Japanese billionaire to become the first private passenger to make the trip. That flight is planned for 2023.