We now know why SpaceX is latest Starship prototype went up in flames last week.
The stainless steel vehicle, known as SN11 (“Serial Number 11”), is on a test flight last Tuesday (March 30) from SpaceX’s South Texas facilities, near the Gulf Coast town of Boca Chica.
SN11 raised the plan to a maximum altitude of 10 km (10 miles), and the 50-meter-long vessel also checked a number of boxes on its way down. But SN11 did not crash, but exploded in a massive fireball – due to a plumbing problem, founder and CEO of SpaceX Elon Musk announced today (April 5).
Video: Watch SpaceX’s Starship SN11 launch on a test flight
“Rise phase, transition to horizontal and control during free fall was good. A (relatively) small CH4 leak led to fire on engine 2 and a fried part of the aviation, which started a hard start trying to burn in. CH4 turbo pump. It will be fixed 6 ways until Sunday, ” Musk said via Twitter today.
CH4 is methane, the driving force behind SpaceX’s powerful, next-generation Raptor engine. And a “hard start” refers to ignition when there is too much fuel in the combustion chamber and therefore the pressure is too high – not a good thing for any engine.
SpaceX is developing Starship to take humans and cargo to the moon, Mars and other distant destinations. The transport system consists of two elements, both of which will be reusable again: the spaceship Starship and a giant first-phase booster called Super Heavy.
Both Starship and Super Heavy will be powered by Raptors – six for the final Starship and about 30 for the big booster, Musk said. SN11 played three birds of prey, just like each of its three predecessors, SN8, SN9 and SN10, which were launched on 6-mile high test flights on December, February and early March respectively.
All four flights were generally equal, and the prototypes performed well to the end. SN10 even ended up in one piece, but explodes about eight minutes later.
SpaceX will keep trying to get the landing right. The company has already built the next Starship prototype, known as SN15, and it will soon have to turn to the sky. (Yes, SpaceX goes directly from SN11 to SN15.)
Mike Wall is the author of “Out there“(Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for alien life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.