1. Basic information
Long March 5B was developed based on the Long March 5 launch vehicle. The First Academy of Aerospace Science and Technology is the overall unit, and the Eighth Academy of Aerospace Science and Technology is responsible for the research. It is my country’s first large-scale cryogenic rocket to implement “zero window” launch. As my country’s new generation launch vehicle with the largest low-Earth orbit carrying capacity, Long March 5B is also my country’s first one-stage and a half configuration rocket. It has few stages, no separation between stages, a simple system and high reliability.
Altitude ｜ Core stage diameter ｜ Mass ｜ Number of stages ｜ Low Earth orbit load
53.657m ｜ 5m ｜ About 849t ｜ Level 1 and a half ｜ >25t
2. Rocket composition
(1) Fairing
1.Basic parameters
Diameter | Length | Effective clear space diameter | Volume
5.2m ｜ 20.5m ｜ 4.5m ｜ ＞345 m3
2.Separation plan
The fairing is separated by rotation.
(2) Core level one
1.Basic parameters
Diameter ｜ Length ｜ Filling volume ｜ Propellant
5m | 33.158m | 166.66t | Liquid hydrogen and liquid oxygen
2.Supercharging system
The first stage of the core adopts an autogenerated pressurization system, the liquid oxygen tank adopts an open autogenerated pressurization scheme, and the liquid hydrogen tank adopts a closed autogenerated pressurization scheme.
3.Engine system
The core stage uses two double-swing YF-77 hydrogen-oxygen engines. The engines use a gas generator cycle. The sea level thrust is 52.8t, the specific impulse is 316.7s, the vacuum thrust is 71.4t, the vacuum specific impulse is 428s, and the thrust-to-weight ratio is 38.4.
4. Related improvements
Compared with the Long March 5, the Chang 5B has adjusted its structural plan and successfully reduced its weight by about 400kg by using lightweight carbon fiber composite materials combined with an aluminum honeycomb sandwich.
(3) Booster
1.Basic information
Diameter ｜ Length ｜ Filling quantity ｜ Take-off mass ｜ Propellant
3.35m ｜ 27.6m ｜ 142.8t ｜ 156.6t ｜ Liquid oxygen kerosene
2.Supercharging system
The liquid oxygen tank is heated and pressurized by normal-temperature helium. The helium cylinder is installed inside the nose cone. After being heated by the helium heater, it enters the storage tank for pressurization. The kerosene tank is pressurized by normal-temperature helium, and the gas cylinder is installed on the inter-box section.
3.Engine system
The booster engine is a YF-100FHII liquid oxygen/kerosene engine (composed of two YF-100 engines and a dual machine frame). It adopts an oxygen-rich pre-combustion staged combustion cycle, with a sea level thrust of 124.8t, a specific impulse of 300s, a vacuum thrust of 136.7t, and a specific impulse of 335s.
