Musk predicts next Starship launch in a ‘couple of months’
WASHINGTON — SpaceX CEO Elon Musk said the first integrated test flight of the company’s Starship vehicle met his expectations despite a series of engine failures and other malfunctions that ultimately caused the rocket to lose control.
Musk, speaking in an April 29 chat for subscribers of Twitter, the social media company he acquired last year, predicted the company would be ready to make another launch attempt in about two months with a better chance of reaching space.
“The outcome was about what I expected and maybe slightly exceeded my expectations,” he said. Those expectations, he said, were that the vehicle would get off the pad and get “significant” data during flight, including through maximum dynamic pressure, or max-Q. “Overall, I actually feel it was a great flight.”[ads1];
Musk offered a summary of the flight, noting that problems began immediately upon takeoff when 3 of the 33 Raptor engines in the vehicle’s Super Heavy booster either failed to start or cut off during takeoff. “These engines didn’t explode, but the system didn’t think they were healthy enough to bring them to full thrust.”
He added that the 30 working engines were the minimum required to lift off, causing a distinct lean to the vehicle as it cleared the pad.
At T+27 seconds, a Raptor-designated engine 19 lost communications at the same time that “some sort of energetic event” broke off part of the heat shield around that engine and three others. At the time, there were “visible fires” coming from the rear end of the rocket, he said.
At T+62 seconds, there was additional heat shield damage around another Raptor, engine 30, although that engine continued to operate. At T+85 seconds, “things really hit the fan,” he said, with a loss of communication with another engine. “From about this point on, we lose thrust vector control of the rocket,” he said, meaning it could no longer steer.
It was not clear what caused the engine failures, but Musk said there appeared to be no damage from the “rock tornado” of debris from the concrete pad created by the thrust of the engines on ascent. “Oddly, we don’t see evidence of the mountain tornado actually damaging engines or heat shields in a material way,” he said. “It may have, but we have yet to see evidence of it.”
SpaceX made no attempt to separate the Starship upper stage from the Super Heavy vehicle as it tumbled in later stages of flight. Musk said that while controllers initiated the flight termination system, it took much longer than expected, about 40 seconds, for explosives to detonate the vehicle’s tanks.
The requalification of the flight termination system will be the long-term element for the next launch, he predicted, with the next vehicle and a repaired pad likely to be ready in six to eight weeks. “Hopefully we’ll be ready to fly again in a couple of months.”
Musk played down the damage to the pad itself, including concrete debris scattered over nearly 400 acres around the pad and a cloud that deposited a sand-like material more than 10 kilometers away. “The rust was basically sand and rocks,” he said, “but we don’t want to do that again.”
The change to the pad includes the placement of a water jacketed “steel sandwich” under the launch mount. “You’ve got what’s basically a massive, super-strong steel shower head that points up,” he said, with that water flow system taming dust and debris.
SpaceX had been working on that device before launch, but it wasn’t ready in time. “If we had expected to dig a hole, we wouldn’t have flown,” Musk said. Data from the static fire test in February, when 31 of 33 Raptor engines fired at 50% of rated thrust, caused “fairly modest erosion” of Fondag, the heavy-duty concrete used on the pad. “We thought it would be fine for one launch.”
He said SpaceX will also replace damaged tanks in the tank farm at the pad that were already set to be replaced with vacuum-jacketed versions. The launch tower itself suffered no “meaningful” damage, he added.
The next launch will use a Super Heavy booster called Booster 9, but he said the company had not decided which of the Starship upper stages will fly. “The engines on Booster 9, which is next, are much newer and more consistent, and with significant reliability improvements,” he said, along with improved shielding. “I think we’ll see a much more robust engine situation with the Booster 9.”
He was optimistic that the second launch will at least make it through stage separation. “Our goal for the next flight is to get to staging and hopefully successfully stage and get into orbit,” he said. “I think we have a decent chance of getting into orbit on the next flight.”
He later said in the nearly hour-long call that he gave a “better than 50% chance of reaching orbit” on the next launch. That launch, however, will be a repeat of the flight profile of the original flight, a “near-orbital” trajectory that would see the Starship splash down off the coast of Hawaii 90 minutes after liftoff, short of a full orbit.
Musk estimates that SpaceX will attempt four to five Starship launches this year. “I would be surprised if we go out this year without getting into orbit,” he said, giving the company an “80%-plus probability” of doing so, increasing to nearly 100% within 12 months.
He said the company will spend about $2 billion this year on Starship, which he argued the company can support without raising outside funding.
“Once again, excitement is guaranteed,” Musk said of the next launch. “Success is not.”
