LM-3B/Yuanzheng 1 Puts Six BeiDou Satellites into Space

A LM-3B/Yuanzheng 1 is putting the 35th and 36th BeiDou satellites into spacePhoto: GAO Nan

At 12:23 Beijing time on October 15 and 22:07 Beijing time on September 19, two LM-3B/Yuanzheng 1 launch vehicles lifted off from the Xichang Satellite Launch Center, putting the 39th and 40th BeiDou satellites and the 37th and 38th BeiDou satellites of the BeiDou Navigation Satellite System (BDS) into their predetermined orbits respectively. The two pairs of Bei-Dou satellites are the 13th -16th satellites of the BeiDou global navigation satellite system (BeiDou 3), which are of sign ificance for BeiDou 3 global networking. They were the 92nd and the 91st missions of the LM-3A series launch vehicle, the 286th and the 285th flights of the LM family carrier rocket.

The BeiDou 3 satellites were developed by the China Academy of Space Technology under CASC, which are key to the success of the following networking mission. On the basis of the technology and experiences of the predecessors, three incremental payloads were added onboard these two satellites for international search and rescue, global short message service,and plasma and surface charge risk monitoring.

The application of international search and rescue system sign ifies BDS going global and will further strengthen the ability for international search and rescue organizations, providing Bei-Dou services for the world. The global short message service has 3 functions including short message, location report and emergency search and rescue. Compared with BeiDou 2, Bei-Dou 3 is able to supply short message service to broader areas.The plasma and surface charge risk monitor capability will jointly detect the plasma parameters and the surface charge effect generated in the orbit where the navigation satellites operate. The space weather data obtained will help to accumulate experience and provide guidelines for follow-on satellite safety and reliability designs.

A LM-3B/Yuanzheng 1 is putting the 39th and 40th BeiDou satellites into spacePhoto: XIE Qiyong

The 37th and 38th BeiDou satellites are being launched atop a LM-3B/Yuanzheng 1Photo: NAN Yong

Nearly a month ago, a LM-3B/Yuanzheng 1 launch vehicle conducted the 90th mission of the LM-3A series launch vehicle at 07:52 Beijing time on August 25, sending 2 BeiDou satellites into orbit successfully. The two satellites are the 35th and 36th of the BDS, also the 11th and 12th of the BeiDou 3. This was the 283rd flight of the LM family carrier rocket.

The LM-3B/Yuanzheng 1 launch vehicle which carried out these missions was developed by the China Academy of Launch Vehicle Technology. It is a four-stage carrier rocket with base stages and an upper stage.

To adapt the upper stage, the base stage had a strap-on three-stage liquid rocket developed on the basis of the LM-3B launch vehicle with the first stage using 4 boosters. The upper stage was an orbital launcher specially developed for launching the new generation BeiDou navigation satellites using conventional propellants.

The LM-3B/Yuanzheng 1 carrier rocket changes a series of software for ground propellant filling, which is matched with the adjusted liquid level sensor in the third stage of the rocket, thus better adapting to the filling adjustment for emergency. (YANG Cheng, DAI Zhengying/China Space News)