More than two years after its second flight ended in failure, China’s biggest rocket, Long March 5, returned to work today successfully lofting a large experimental communications satellite, Shijian-20, into orbit. Roughly equivalent to the U.S. Delta IV Heavy, the Long March 5 is a critical component of China’s future robotic and human space flight plans.

Long March 5, or CZ-5, lifted off from the Wenchang Satellite Launch Center on China’s Hainan Island at 7:45 am Eastern Standard Time this morning. No official livestream was available, but amateurs covered the launch live and posted video to YouTube and China’s microblogging website Weibo. Some of the video along with English-language commentary was tweeted by @launchstuff, @AJ_FL and @cosmicpenguin among others.

The South China Morning Post (SCMP) reported that Chinese officials declared this launch a “complete success” once the Shijian-20 satellite was in orbit. It is still making its way to its final destination in geostationary orbit (GEO). According to SCMP, it will be one of the largest communications satellites in GEO and quotes an unnamed Beijing-based space expert as saying it will “change China’s position from a follower to a leader in space communications.”

The first launch of Long March 5 in 2016 was declared a success at the time, but SCMP notes that it “failed to reach the speed required for the early phase of the flight, though it managed to lift its satellite cargo into orbit,” hence earning the success label.

The second launch in July 2017 failed completely, however, when a turbo pump failed.

Now, two-and-half-years later, they appear to have worked out the bugs.

China’s Chang’e-5 mission has been waiting all this time for the Long March 5 so it can be launched on its sample return mission to the Moon. Also on tap is a robotic orbiter/lander/rover mission to Mars scheduled for launch in the summer of 2020. Long March 5 is also needed to launch the three 20-ton modules that will form the China Space Station, which China hopes to have completed by 2022.

SCMP reports that the Long March 5 can lift 28 metric tons (MT) to low Earth orbit (LEO), though previous Chinese reports put it at 25 MT. The United Launch Alliance’s (ULA’s) Delta IV Heavy for many years was the most capable U.S. rocket at 28.4 MT to LEO. More recently, SpaceX’s Falcon Heavy, capable of placing 64 MT into LEO, is the most powerful. NASA is building the Space Launch System (SLS) that will be able to launch 70 MT to LEO in its initial configuration, with plans ultimately to increase that to 130 MT.