Space X scrubs launch of Starship, the world's largest rocket

Updated April 17, 2023 at 10:42 AM ET

The commercial spaceflight company SpaceX scrapped its first scheduled test flight of Starship, a huge, stainless-steel rocket that could one day carry humans to the moon, Mars and beyond.

The first launch attempt was set to take place in South Texas during a 150-minute window on Monday morning. Just about 10 minutes before the anticipated liftoff, SpaceX CEO Elon Musk said in tweet that a valve appeared to be frozen, rendering the mission untenable.

A pressurant valve appears to be frozen, so unless it starts operating soon, no launch today

The issue occurred in the spacecraft's super-heavy booster, the company said on a livestream. The booster uses 33 engines working in synchronicity to lift the 400-foot-tall rocket off the ground.

The decision to use such a large number of engines — more than any other rocket ever made — is a trade-off, says Paulo Lozano, director of MIT's space propulsion laboratory.

"Having that large number of rocket engines firing simultaneously — it's actually quite hard. I think that's going to be one of the biggest challenges," he says.

Adding to the challenges is SpaceX's choice of fuel: methane. Most high-powered rockets use hydrogen for fuel because it is lightweight and highly efficient, Lozano says. Methane is cheaper to produce and easier to handle than hydrogen.

But methane and the rocket's oxidizer oxygen need to be chilled to very low temperatures, which may explain the frozen valve.

SpaceX says it'll need a minimum of 48 hours to plan until the next launch can be possible, said systems engineer Kate Tice. Musk said the team would try again "in a few days."

"With a test such as this, success is measured by how much we can learn, which will inform and improve the probability of success in the future as SpaceX rapidly advances development of Starship," SpaceX said in a tweet during Monday's launch countdown. The team continued going through the motions as a wet dress rehearsal, stopping just before igniting the engines.

The stakes could not be higher, at least to hear SpaceX CEO Elon Musk speak about the mission.

"Eventually the Sun will expand and destroy all life," Musk said, standing before the giant rocket about a year ago. "It is very important — essential in the long-term — that we become a multi-planet species."

Musk hopes Starship will provide a critical step to becoming multiplanetary, by allowing large payloads to be carried into orbit for cheap. His goal is for Starship to someday transport the first people to Mars.

SpaceX also has a business interest in seeing its mammoth rocket fly. Starship could be used to launch large numbers of the company's internet-providing "Starlink" satellites.

Starlink is seen as a key part of SpaceX's future, and Starship would allow the network to rapidly grow, says Tim Farrar, the president of TMF associates, a telecom consulting firm.

NASA is also paying SpaceX to develop a version of Starship to visit the moon, though that mission is likely still several years away.

The launch of Starship comes at a difficult time for the tech industry, Farrar notes. SpaceX is currently trying to raise additional capital to keep the development of Starship and Starlink going.

For now, investors seem happy to let SpaceX try out its massive, potentially interplanetary rocket. But Farrar says that if the launch fails and Starship falls further behind schedule, it could affect all of SpaceX's business, especially in the current financial climate.

SpaceX seems to understand the risks. It has had many rockets blow up during testing in the past, a development strategy that's worked well for them overall.