XICHANG, Sept. 19 -- China on Thursday launched two new satellites for the BeiDou-3 Navigation Satellite System (BDS-3) from the Xichang Satellite Launch Center in southwest China's Sichuan Province.

The two satellites, the 59th and 60th satellites of the BeiDou family, were launched at 9:14 a.m. (Beijing Time) by a Long March-3B carrier rocket and the Yuanzheng-1 (Expedition-1) upper stage attached to the carrier rocket.

They are the second group of medium Earth orbit (MEO) satellites launched since BDS-3 was formally commissioned to provide satellite navigation services worldwide. After entering orbit and completing in-orbit tests, they will be connected to the BDS system.

Compared with the previous group of MEO satellites, these new satellites feature upgraded onboard atomic clocks and new inter-satellite link terminals.

They will further improve the reliability of the BDS-3 system and the performance of its positioning, navigation and timing (PNT), global short message communications and other services.

The satellites will also be used for new technology tests for the next generation BDS system, according to the China Satellite Navigation Office.

China will accelerate the construction and development of the next-generation BDS system, and increase technical research on a variety of PNT methods that do not rely on satellites, said the office.

The satellites and launch vehicles were respectively developed by the Innovation Academy for Microsatellites under the Chinese Academy of Sciences and the China Academy of Launch Vehicle Technology under the China Aerospace Science and Technology Corporation.

This launch was the 535th mission involving Long March series carrier rockets.