SpaceX delays the launch of its giant Starship rocket to replace a part – Ars Technica

BOCA CHICA BEACH, Texas — The launch of SpaceX’s second full-size Starship rocket from South Texas is now scheduled for Saturday, a day later than planned, according to company founder Elon Musk.

The 24-hour delay will give SpaceX technicians at the company’s launch facility, known as Starbase, time to replace a component of the rocket’s stainless steel Super Heavy booster. There is a 20-minute launch window on Saturday, which will open at 7 a.m. CST (1 p.m. UTC), shortly after sunrise in South Texas.

A delay at this stage is not surprising. Starship is a complex launch vehicle with a total of 39 methane-burning engines, each producing about half a million pounds of thrust, powering its booster stage and upper stage. And this is only the second test flight of SpaceX’s new full-size rocket, measuring nearly 121 meters tall, the largest launch vehicle ever built.

No time wasted

Impressively, assuming SpaceX successfully completes the repair in time for a launch attempt Saturday morning, it would be another example of how quickly Starbase, located on a remote stretch of the Texas Gulf Coast, is progressing. is Brownsville, just a few miles away. north of the US-Mexico border.

Hours after making the decision to replace the part at the top of the Super Heavy booster stage, SpaceX’s ground team detached the bullet-shaped Starship vehicle, itself about fifteen feet tall. stages, from the top of the rocket below. SpaceX uses the name Starship for both the rocket’s upper stage and the entire launch vehicle.

It’s pretty standard work at SpaceX’s rocket base in South Texas, where teams have raised and lowered the craft several times during previous tests and launch attempts. Two metal arms, colloquially called “wands”, hooked onto the sides of the Starship vehicle, lifted it a few feet above the Super Heavy booster, then swung it sideways and lowered it to the ground.

The looming structure towering over the coastal mudflats seemed to come to life, letting out creaks and groans as the two holding arms slowly moved down the rails that ran up and down the launch pad support tower. It took less than half an hour to remove the top third of the rocket and place it on the ground.

A few hundred meters away, a large number of happy spectators and SpaceX enthusiasts took photos. They will have to wait at least one more day to see this behemoth fly.

SpaceX needed to remove the Starship’s upper stage, numbered “Ship 25” in SpaceX parlance, to allow technicians to access the part to be replaced on the Super Heavy booster, designated “Booster 9.”

“We need to replace a gate fin actuator, so launch is postponed until Saturday,” Musk posted on his X social media platform on Thursday.

The Super Heavy booster has four of these grid fins, which function like small wings, at the top of the vehicle. They provide aerodynamic stability and some steering authority when the booster descends to the ground. During this test flight, SpaceX aims to guide the booster to a controlled, rocket-assisted landing in the Gulf of Mexico, approximately 20 miles (32 kilometers) off the coast of Texas.

In the future, SpaceX wants to land the Super Heavy booster, larger than the fuselage of a Boeing 777 airliner, vertically on its launch pad for rapid reuse. The Starship’s upper stage is also designed for recovery and reuse.

Electric actuators drive the grid fins, providing the power to pivot and rotate them when they receive split-second inputs from the booster’s guidance system. The component that SpaceX will replace is apparently one of these actuators.

Next, the Starbase team will need to reattach the Starship upper stage on top of the Super Heavy first stage. After some additional checks, SpaceX executives could give the green light for a final countdown early Saturday.

SpaceX received a commercial launch license for the Starship test flight from the Federal Aviation Administration on Wednesday, after months of safety and environmental reviews by federal regulators. Scrutiny from regulatory agencies followed the Starship’s first test flight in April, which ended when the rocket spun out of control and self-destructed minutes after liftoff.

The Starship team added a new water deluge system to the launch pad to absorb the heat and acoustic energy generated by the simultaneous firing of 33 booster engines. When the engines ignited during the April test flight, the explosion fractured the concrete foundation beneath the pedestal where the rocket sits before liftoff.

There are also key changes to the rocket’s stage separation system, thrust vector or steering control mechanisms, as well as improvements to reduce the risk of fuel leaks, which have led to fires in the engine compartment during the April test flight.

This next flight is still experimental and officials hope to learn things that will lead to more design changes. If all goes perfectly, the flight profile will allow Starship to circumnavigate the globe, reaching an altitude of approximately 150 miles before re-entering the atmosphere over the Pacific Ocean for a targeted splashdown north- West Hawaii.

But as Ars reported earlier this month, there are degrees of success. Basically, the test flight is a learning exercise, but some results are better than others as SpaceX works to make Starship an operational vehicle for missions ranging from launches to deployment of Starlink internet satellites to landings on the Moon for NASA.

“This is another chance to put Starship in a real flight environment, maximizing everything we learn,” SpaceX said. “Rapid iterative development is essential as we work to build a fully reusable launch system, capable of transporting satellites, payloads, crews and cargo to various Earth, lunar and other orbits and landing sites. Martians.”