Long March 3B adds another spacecraft duo for China’s BeiDou satellite navigation system
Continuing its busy 2018 launch manifest, a Long March 3B rocket lifted off Monday, Oct. 15, 2018, to deliver the two newest BeiDou-3 spacecraft for China’s homegrown satellite navigation network.
The rocket lifted off at 12:23 p.m. local time (4:23 GMT / 12:23 a.m. EDT) from the Xichang Satellite Launch Center in Sichuan Province. Confirmation of launch success came from the state-run Xinhua press agency almost six hours after the flight started.
Although the mission was acknowledged by Chinese media outlets, details about pre-launch preparation and about its orbital flight remain undisclosed. Beijing initially targeted Oct. 5 for the flight, but decided to postpone the mission, not informing the reason behind this move.
What was revealed to the public was that the dual payload was delivered into a medium-Earth orbit (MEO), most likely at an altitude of some 13,360 miles (21,500 kilometers), inclined approximately 55.5 degrees. According to Xinhua, from launch to satellite deployment was about three hours.
“The satellites entered their planned orbit after flying more than three hours, and will work with the 14 BeiDou-3 satellites already in orbit,” the press agency said.
There were reports that some used parts of the rocket’s first stage fell to the ground in the Chinese district of Debao and the Guangxi Zhuang Autonomous Region.
Designated BeiDou-3 M15 and M16, the two newly-launched satellites were developed by the Innovation Academy for Microsatellites of the Chinese Academy of Sciences (CAS). Both spacecraft are based on a newly-developed dedicated satellite bus with a phased array antenna for navigation signals and a laser retroreflector.
Each BeiDou-3 MEO satellite weighs about one metric ton, has two deployable solar arrays and is designed to be operational for about 12 years. The dimensions a spacecraft of this type measure 7.38 by 3.28 by 4.0 feet (2.25 by 1.0 by 1.22 meters).
BeiDou-3 M15 and M16 belong to the third phase of the BeiDou (BDS) satellite navigation system, and are the 39th and 40th satellites of the program. Named after the Chinese term for the Big Dipper constellation, the project was formally started in 1994 and the first satellite was sent aloft in 2000.
By 2012, a regional network had begun to take shape, which provided positioning, navigation, timing, and short message services in China and several other Asian countries.
“The system now covers more than 50 countries with a total population of more than three billion. By 2020, BeiDou will provide first-class services around the globe,” Xinhua reported.
China plans to have the BeiDou-3 constellation consist of some 27 BeiDou-3M satellites in MEO, five BeiDou-3G satellites in a geostationary orbit, and three BeiDou-3I satellites in an inclined geosynchronous satellite orbit. The first BeiDou-3 satellite was launched in March of 2015.
Next BeiDou-3 spacecraft, designated M17 and M18, are scheduled for launch from the Xichang Satellite Launch Center atop a Long March 3B booster on Oct. 25, 2018.
The three-stage Long March 3B rocket is 180 feet (55 meters) tall and capable of sending up to 12 metric tons of payload into low-Earth orbit or five metric tons of cargo into a geostationary transfer orbit. For Monday’s launch, this rocket was equipped with a Yuanzheng-1 upper stage. This was also the 287th flight for a member of the Long March rocket series and the 28th launch carried out by China in 2018.
Video courtesy of CGTN
Tomasz Nowakowski is the owner of Astro Watch, one of the premier astronomy and science-related blogs on the internet. Nowakowski reached out to SpaceFlight Insider in an effort to have the two space-related websites collaborate. Nowakowski's generous offer was gratefully received with the two organizations now working to better relay important developments as they pertain to space exploration.