The launch of the biggest rocket ever was spectacular. Twice the force of the rocket that took astronauts to the Moon, the SpaceX Starship cleared its Texas tower on a sunny Thursday morning. Four minutes later, the pieces of that massive spaceship were falling into the Gulf of Mexico. Starship didn’t reach space, it didn’t fly to just off the coast of Hawaii and hit the ocean as planned, but this test is being celebrated as a success- a successful failure. There are reasons for that.
This massive rocket has a lot of moving parts. Getting those parts to work together is a technical challenge. Elon Musk’s company has found this fly, fail, improve system to work for its efforts to create reusable rockets. The booster that pushed the Starship skyward has 33 Raptor engines. Twenty of them are static, mounted on an outer ring, while the 13 inner engines can move to help control the rocket’s flight. This was the first time that booster has flown.
Musk attempted to lower expectations about this test flight to the two-stage rocket. He said success would be getting off the launchpad without blowing up. That happened and led SpaceX workers to celebrate. Musk didn’t want to have to rebuild his launchpad in Boca Chica, Texas. He calls the ground systems “stage zero,” an important part in launching rockets.
SpaceX has not briefed the media on what went right and what went wrong. Here is what I saw in the four minute flight.
-There was a short hold at T-:40 for a purging problem (pushing out residual fuel with inert gas to avoid explosive hazard) in the Starship, also known as the second stage. There were some issues with pressurizing the super-heavy booster’s fuel tanks.
-Countdown proceeded and the super-heavy boosters were ignited. It took a couple seconds for launch control to call it out, but there was a liftoff call and the massive rocket cleared the tower. It was a sight nearly blocked by all the exhaust.
-Launch control continued to call out “nominal,” normal, in the early moments of the flight. But SpaceX’s graphic showed that not all the 33 Raptor engines were operating. During the short flight, between three to six of those engines were not working. One camera shot of the booster clearly showed six of the engines not operating.
-At about T+2:30 something started to look problematic when of the engines seemed to be operating unevenly. An onboard camera showed the rocket spinning a bit on its axis that didn’t seem planned. At T+2:33 the SpaceX graphic of the attitude of the rocket flipped. What is supposed to happen is that after the first and second stages separate, the first stage flips and prepares to return to Earth. It appears the programmed flip started before separation because there was no separation. An onboard camera appeared to show some smoke or exhaust in the inner stage between the two stages. That could be explosive bolts that activated, but did not separate the stages. It appeared that Starship attitude engines were fighting the engines of the booster causing the unusual movements. This is one of the big mysteries of this test flight.
-At T+2:48 the attitude of the rocket appeared to change again as we hear the last call from launch control, “booster engine cutoff.” It looked likes the booster continued to burn and the rocket started a counter-clockwise cartwheel. Workers watching suddenly went quiet on the webcast. One of the hosts said, “we are still waiting for separation.” Another host, at T+3:48 said, “obviously, this does not appear to be a nominal situation.”
-At T+3:59 the vehicle exploded. It could have been a self-destruct command. One of the hosts commented at the time of the explosion, “that everything after clearing the tower was icing on the cake.” There were actually two explosions separated by about two seconds which could be self-destruct and then the remaining fuel going off.
The company considers failure part of the learning process. They use a cute saying for these kind of incidents. The Starship suffered a RUD- a rapid unscheduled disassembly.
SpaceX said in a tweet, “success comes from what we learn, and today’s test will help us improve Starship’s reliability.” Elon Musk offered his congratulations and said he and the company, “learned a lot for next test launch in a few months.”
Former astronaut and a past consultant for SpaceX, Garrett Reisman, said. “Now that was impressive. Great work.” Another former astronaut, Scott Kelly, said, “Great launch.” He noted it looked like a great test of the flight termination system.
And then there was NASA. A Starship is contracted to be the human landing system to put American astronauts back on the lunar surface. The NASA Administrator tweeted his congratulations. “Every great achievement throughout history has demanded some level of calculated risk,” Sen. Bill Nelson said.
While it may have seemed unusual to see the SpaceX employees celebrating with cheers and hands up as the pieces to the vehicle were falling, this partial failure was a success several years in the making.