SpaceX prototype Starship rocket explodes after test in Texas

A fourth prototype of SpaceX’s next-generation Starship rocket exploded Friday after a test at the company’s development facility in Texas.

The company was conducting a trial of the rocket’s engine, in a test on the ground known as a static fire. A few minutes after the test, which initially appeared successful, the Starship prototype identified as Serial Number 4 ruptured in a fiery explosion.

This prototype is distinct from the company’s Falcon 9 rocket and Crew Dragon spacecraft, which this weekend is set to launch NASA astronauts from Florida. That rocket system has previously launched satellites and cargo to space successfully dozens of times, after years of development and testing.

The rocket is called Starship, which the company is developing with the goal of launching people and cargo to the moon and Mars. The rocket is designed to be reusable so SpaceX can launch and land it multiple times, like a commercial airplane. Starship’s shiny external appearance is because of the type of stainless steel that SpaceX is using to build the rocket.

This latest Starship prototype is the fourth that SpaceX has built. While it made it the furthest along in tests, passing several critical milestones, the company has yet to begin flight testing its most recent design. A previous iteration, known as Starhopper, completed a short launch and landing flight test in October.

The SN4 prototype had passed several critical milestones during development, including a pressurization test that had foiled previous version of the rocket. So far SpaceX has built and destroyed four Starship prototypes, due to a variety of different failures during testing. SpaceX has been aggressively developing Starship, with the company’s leadership setting the goal of reaching space later this year – and the moon by 2022.

Subscribe to CNBC PRO for exclusive insights and analysis, and live business day programming from around the world.