Yesterday, the launch of a Chinese communications satellite ended in failure when the rocket carrying the probe somehow malfunctioned during flight. It’s a significant loss for China since the vehicle that failed — the Long March 5 — is the country’s premier heavy-lift rocket. And its failure could have a big impact on the future of China’s ambitions in space.

It’s still unclear exactly what happened. Shortly after the flight, China’s official press agency, Xinhua, simply reported that “an anomaly occurred” during launch and that there would be an investigation into the problem. But some clues seem to indicate the issue may have started in the main core of the rocket. A plume of gas was seen around the main engines of the vehicle about six minutes into flight, according to Spaceflight 101.

“This is important. The Long March 5 is their flagship rocket.”

It was only the second launch of this particular type of rocket. However, China has big plans for this vehicle: the Long March 5 is one of the most powerful rockets in the world, nearly matching the capability of the US’s Delta-IV Heavy. The next flight of the Long March 5 is meant to go to the Moon, sending two modules to the lunar surface — one to collect samples and another to return those samples to Earth. This mission was tentatively scheduled for November of this year, but yesterday’s failure makes that timeline uncertain.

“This is important. The Long March 5 is their flagship rocket,” Jonathan McDowell, an astrophysicist at Harvard and spaceflight expert, tells The Verge. “It’s key for their ambitions. ... They’ve got to get it right.”

The rocket is just one way China has significantly updated its spaceflight program. For most of the 20th century, the country launched satellites fairly infrequently, maybe a handful each year. But then in the 1990s, China ramped up its space initiatives. The country has been steadily increasing the amount of yearly launches, and the scope of these missions continues to grow. China made headlines in 2013 when it put a lander and rover on the Moon’s surface. And last year, China launched its longest crewed spaceflight mission to date. For 30 days, two taikonauts — China’s astronauts — stayed on board the Tiangong-2 space station, a laboratory meant to test out technologies needed for a future, more permanent orbital station.

China also started developing a new family of Long March rockets to take over as the country’s primary vehicles: the Long March 5, the Long March 6, and the Long March 7. These vehicles, which just started flying a couple of years ago, represent a new direction for the country’s spaceflight technology. They use liquid oxygen and kerosene — propellants that are much less toxic and corrosive than what previous Long March rockets used. They also take off from a brand new launch site on China’s Hainan Island, which allows the rocket to fly over water after takeoff. That avoids rocket parts falling near inhabited areas.

It’s with these rockets, especially the Long March 5, that China hopes to do big things in space. Not only is the Long March 5 needed for the lunar sample return mission, it’s also meant to launch the core module for China’s future space station, which is slated to begin construction in 2019. There are even plans to launch a mission to Mars in 2020 using the Long March 5; that mission would include an orbiter, a lander, and a rover.

Yesterday’s failure could put a slight hold on China’s growth

China’s ambition has led to a lot of speculation over whether the country will at some point match the US in spaceflight capability. But yesterday’s failure could put a slight hold on that growth, and it could spell a problem for the Long March 6 and 7 — not just the 5. “The 5, 6, and 7 use the same components,” says McDowell. “A problem with one of them potentially affects all of them. And their whole future program depends on these family of rockets being reliable.”

The good news is that the inaugural launch of the Long March 5 went just fine — so the problem isn’t catastrophic. There likely isn’t a major flaw with the rocket’s design, and the fact that the failure arose minutes after takeoff, not just seconds, means there will be a lot of data to go through to help determine the problem. “As failures go, it’s not the worst,” says McDowell. “But it’s certainly a blow to them.”

Still McDowell doesn’t think the country will stay on the sidelines forever. The lunar sample return may slip until next year, but he’s confident the country will push ahead soon. “This is one event in a very broad and aggressive Chinese space program that’s been pushing forward the past couple of years,” he says. “It’s not going to slow them down for very long.”