- Details of what happened are unknown.
- Rocket carried communications satellite.
Carrying an experimental communications satellite, China's largest rocket lifted off at 7:23 p.m. local time (7:23 a.m. ET) toward clear skies from the seaside Wenchang space launch center on the southern Chinese island of Hainan.
But 40 minutes later, the state-run Xinhua news agency flashed a headline declaring the launch a failure -- without providing any details.
Dubbed "Chubby 5" for its huge size -- 5 meters in diameter and 57 meters tall -- the LM-5 rocket is designed to carry up to 25 tons of payload into low orbit, more than doubling the country's previous lift capability.
On Twitter, Xinhua initially posted: "#BREAKING: China's launch of Long March-5 Y2 carrier rocket fails."
It then tweeted: "Anomaly was detected during its flight and further investigation will be carried out."
The launch failure means further delay for a series of planned Chinese space endeavors -- including its robotic and eventual human lunar programs -- according to Joan Johnson-Freese, a professor at the US Naval War College and an expert on China's space program.
"With the LM-5 being new technology, the failure points out that rocket science is extremely difficult and why more countries don't have the technology," she said.
Before the launch attempt, Johnson-Freese said the rocket would give China "heavy lift capabilities" needed to develop a large space station as well as new capabilities to reach interplanetary destinations.