One of China’s biggest rockets flew again this Wednesday. Chang Zheng 3B/E successfully launched the Beidou-3 G4 payload at 2:49 AM UTC. The launch was conducted from launch complex 2 of the China Xichang Satellite Launch Center (XSLC). This is already the third flight of the massive first-generation launcher.
Beidou-3 G4 is a geostationary Earth orbit satellite part of the Chinese Beidou satellite navigation constellation. They provide high-accuracy and high-reliability positioning and timing service around the globe with their DFH-3 bus-based architecture.
The first launch of a Beidou satellite happened in October 2000 with the launch of the Beidou test satellite on a Chang Zheng 3A. Since then, over 50 more satellites have been launched.
Beidou has been operating globally and is, since April 2022, also open for private users with an accuracy of 4.4 meters. It can also support timekeeping with an accuracy of at least 20 nanoseconds and determine pace with a minimum accuracy of 20 cm/s.
Since December 2018, the system has been working under the designation of Beidou-3, supported by the previous Beidou-2 satellites and the already launched Beidou-3 satellites that started operation in November 2017.
One of the Beidou constellation’s signature projects is its use in agriculture systems. This system is used to steer machinery from space and, with this, make farming more efficient.
The third generation of satellites have a mass of about 4,600 kg each and are equipped with a small propulsion system for final orbital insertion. This specific satellite was most likely a spare satellite out of the initial launches for the third generation, which was also now deployed. These satellites will be part of a reserve that can start operation whenever needed.
The rocket for this launch was Chang Zheng 3 B/E, also known as the 3B/G2. It is an upgraded Chang Zheng 3B rocket with next-generation liquid rocket boosters and an upgraded center stage. It can lift 11,500 kg to Low Earth Orbit (LEO) and 5,500 to the geostationary transfer orbit (GTO). It is a heavy-lift rocket only used for very massive payloads. Usually, experimental, technology demonstrators and position satellites fit this criterion.
It was also used for signature missions, such as the Change 3 lunar lander landing in December 2013. Over time, more big flagship missions have been transferred to more modern Chinese rockets, such as Chang Zheng 5, with the last few years’ launch of space station modules.
The rocket is built by the China Academy of Launch Vehicle Technology and stands 56 meters tall with a liftoff mass of about 457,970kg. It is a modifiable rocket with an optional fourth stage if the mission needs an additional kick stage. However, this capability is rarely used or utilized for this launch.
While not confirmed, blue tape around the Chang Zheng 3B boosters could indicate another parachute test to land these boosters safely. This would not result in recovery and reuse but mitigate the changes of the cores hitting villages and populated areas at high speed. The tape was spotted around one of the four side liquid boosters.
At liftoff, the rocket features a thrust of about six mN, provided by the YF-20 engines attached to the center stage and the four side boosters.
Chinese Raptor tested
The Chinese full-flow staged combustion engine, heavily inspired by Raptor of SpaceX, was tested on May 12 at the Baolongyu 902-1 test stand. This 200 tons thrust engine is based on methalox and will be featured on future Chinese rockets, such as Chang Zheng 9. The engine also received its name, which is YF-215.
Not much is known about this new rocket engine, but the specifications show similarities to SpaceX Raptor engines. It is not expected to fly before the 2030s, but with it already being tested, that plan might change over the years.
Chang Zheng 9 is a super-heavy lift rocket developed by China for the 2030s. Down the line, the rocket will feature Falcon-9-like first-stage reusability and even Starship-like second-stage reusability. The first stage will be powered by 30 of these YF-215 engines and feature about 3420 tons of propellant. Overall, the rocket is planned to be 114 meters tall with a diameter of 10.6 meters.
Commercial Resupply to the Chinese Space Station
China has released criteria for companies to apply to a commercial resupply program for the Tiangong Space Station. In the criteria, the government asks for at least 1.8 tons of pressurized capacity, at least three months of docking, less than 30 days of launch preparation, and more criteria regarding trash capacity and internal volume.
Currently, the resupply is done by the government-operated and owned Tianzhou missions, but this indicates that China wants to move away from a fully government-operated business. This is part of China’s initiative to work with more private companies for space endeavors. This can also be seen in the launch market, as more and more private companies try to reach orbit in China to support government launch demands.
ZhuQue-2 launch date
According to Chinese media, the launch of the second ZhuQue-2 has a current target date of “Mid to late June.” The first Chinese methalox engine failed to reach orbit just months ago, as the rocket’s third stage misbehaved in the final stages of the flight. The rocket for the second flight was transported to the commercial pad at Jiuquan. Harry Stranger recently spotted the vertical pathfinder of the rocket for checkouts as the company prepares the final steps for the launch campaign.
This pathfinder moved to a horizontal configuration just days ago, which could mean the company finished this part of testing and is lowering the rocket in preparation to put the real flight rocket there.
(Lead image: Chang Zheng 3 B/E ready for flight. Credit: CASC)