Without any prior notice, China carried out on Wednesday, June 29, a secretive lift off of its Long March 4B booster carrying the Shijian-16 No.2 satellite. The rocket blasted off at exactly 11:21 a.m. local time (3:21 GMT), from the Launch Site 43 at the Jiuquan Satellite Launch Center, located in China’s northwest Gansu Province.
Very little is known about this mission and the only indication of the launch came in the form of navigational warnings. According to these pre-launch alerts, the rocket was to fly on an unusual trajectory, towards the south east, aiming for a low-Earth orbit (LEO), inclined 75 degrees. NORAD reports issued after the launch, confirm that the satellite reached LEO with perigee at 370 miles (595 kilometers) and apogee at 383 miles (616 kilometers). The flight lasted about ten minutes.
China insists that the Shijian-16 satellite will be used for conducting spatial environment detection and technological experiments. However, due to its secretive nature and unusual orbit, it is believed that the spacecraft could be also employed for military purposes.
First Shijian-16 satellite was put into space in October 2013. The program dates back to 1971, when the first Shijian spacecraft was launched. Each satellite designed especially for specific mission. During the years, the Shijian satellites were delivered into variety of orbits to fulfill various assignments, including testing electric propulsion, checking thermal control or monitoring and tracking space debris.
The three-stage Long March 4B carrier rocket that was employed for Wednesday’s launch was designed to deliver satellites into low-Earth (LEO) and Sun-synchronous orbits. The 150 ft (46 meters) tall launch vehicle has been in service for more than 16 years and has conducted 28 missions – with only one of them ending unsuccessfully.
With a mass of 249 tonnes, the Long March 4B booster is capable of delivering up to 4.2 tonnes to LEO, 2.8 tonnes to SSO, and 1.5 tonnes to a geostationary transfer orbit (GTO). The rocket’s first stage is 91.5 ft (28 m) long and has 11 feet (3.35 m) in diameter. It is powered by four YF-20B engines. The second stage, 35 ft (11 m) long and 11 ft (3.35 m) in diameter, is equipped with one YF-22C main engine and four YF-23C vernier engines. The 49 ft (15 m) long third stage measures 9.5 ft (2.9 m) in diameter and is powered by two YF-40 engines.
Wednesday’s liftoff was the 231th mission for the Long March family of launch vehicles. This mission was also the second flight of the Long March 4B this year and the third liftoff from the Jiuquan Satellite Launch Center in 2016. It was the third orbital flight this month and so far, the country has launched nine missions this year – all of them successful.
Next Chinese mission is currently scheduled for July when a Long March 2D booster is slated to send the QUantum Experiments at Space Scale (QUESS) technology demonstrator into orbit, also from the Jiuquan. However, the exact date of the launch has yet to be announced.