China launched a Long March 3B carrier rocket on Thursday morning to place two experimental communication satellites into space.

The rocket blasted off at 9:43 am at the Xichang Satellite Launch Center in Sichuan province and soon transported the Smart SkyNet 1A and 1B satellites into a medium-Earth orbit about 20,000 kilometers above the ground, according to the Shanghai Academy of Spaceflight Technology, a subsidiary of China Aerospace Science and Technology Corp and maker of the satellites.

It was the 21st space launch in China this year and the 521st flight of the Long March rocket series.

The academy said in a news release that the satellites were built for Tsing Shen Technology in Shanghai, which aims to establish a space-based broadband internet network consisting of several satellites in medium-Earth orbit.

The two satellites launched on Thursday carry multiple mission payloads such as a multi-beam high-speed microwave link and a two-way inter-satellite laser link. They are tasked with demonstrating technologies needed by the network, it noted.

In the near future, they will be used for trial operations including establishing a direct data link between China and the nation's research outposts in Antarctica, according to the release.