March 2 (UPI) -- Another prototype of SpaceX's Starship rocket exploded during a pressure test at the company's construction yard in Boca Chica, Texas. It was the second such explosion at the Texas site in the past four months.

It wasn't clear if the company knew it would explode, but such testing is designed to find the structural limits of rocket components. SpaceX founder Elon Musk laughed it off on Twitter after posting a video of the Friday night incident.


"It's fine, we'll just buff it out," Musk tweeted.

The tests are done using supercooled liquid. Images captured by independent videographers from outside the plant -- LabPadre and SPadre on YouTube -- showed the bottom of the rocket test article dumping vapor from the liquid before the structure shot up into the air in a bigger cloud of vapor.

The company previously tested a similar structure to failure in November.

SpaceX has been working toward flight design for the stainless steel rocket, according to Musk.

In November, Musk said he hoped to reach Earth orbit with a Starship prototype in about six months, with human passengers by next year. The company has plans to go to the moon and Mars, and to use Starship for planetary commercial flights.