SpaceX’s first full-scale Starship prototype – Mk1 – has experienced a failure at its Boca Chica test site in southern Texas. The failure occurred late in the afternoon on Wednesday, midway through a test of the vehicle’s propellant tanks.
As of a few weeks ago, the Mk1 Starship – which was shown off to the world in September as part of SpaceX’s and Elon Musk’s presentation of the design changes to the Starship system – was to fly the first 20 km test flight of the program in the coming weeks.
The main event of today, the Mk1 Starship’s first cryogenic loading test, involved filling the methane and oxygen tanks with a cryogenic liquid.
During the test, the top bulkhead of the vehicle ruptured and was ejected away from the site, followed by a large cloud of vapors and cryogenic liquid from the tank.
The cryogenic liquid – likely liquid oxygen or liquid nitrogen – was carried by the wind and dispersed over the launch complex.
The top bulkhead was seen landing nearby, but its precise location is unknown.
The bottom tank bulkhead appeared to fail as well. A second cloud of vapor appeared out of the base of the vehicle at the same time that the top ruptured – signaling that the entire internal tank structure may have failed.
“The purpose of today’s test was to pressurize systems to the max, so the outcome was not completely unexpected,” said SpaceX in a statement.
Starship Mk1 was intended to perform the first high-altitude test flights of the Starship program – following Starhopper’s two low-altitude flights.
The first flight of Starhopper reached 18 meters while the second soared to 150 meters.
Starship Mk1 would also have been the first to include three Raptor engines, functioning control fins, and header tanks – which store the propellant used for landing.
SpaceX’s Starhopper test vehicle performing a 150m test flight at their Boca Chica, Texas facility. Credit: SpaceX
However, the failure on Wednesday will certainly throw off the future plans for Mk1, and those of the Starship program as a whole.
But the impact will likely be limited, with SpaceX also noting that a decision not to fly Mk1 had already been made prior to today’s test. Instead, the company will focus on the improved Mk3 design. Elon Musk noted in September that Mk3 would not only have a very different build process, but would also take significantly less time to construct than Mk1.
It’s important to note that Mk1 was not fully assembled during today’s test; its upper fairing was still being worked on at the main assembly site several miles away.
The section at the launch site was made up of the fuel tanks, aft fins, and Raptor engine section.
The Raptor engines were likely not attached to the vehicle, as no engine installations were observed.
SpaceX would have likely attached the fairing after initial on-pad tests were completed, as it includes many systems necessary for flight – including the header tanks and forward fins along with four Tesla Model S 100kWh batteries to power the fin hydraulics.
The bottom half of Starship Mk1 on the launch stand at Boca Chica, taken two days before the failure. Credit: User bocachicagal for NSF.
After the failure on Wednesday, the fate of the nosecone is unknown, but teams will possibly elect to build a brand new one for Mk3.
Mk3 will include not only the three sea-level Raptor engines, but three vacuum-optimized Raptor engines.
Today’s failure was noted by Elon Musk, who confirmed on Twitter that the company will move on to Mk3 Starship design – which will also be built at the Boca Chica test site.
Mr. Musk noted, too, that Mk1 “had some value as a manufacturing pathfinder, but flight design is quite different”.