Category: 3D printing

Beijing Zhongke Aerospace Exploration Technology Co., Ltd. is the first domestic aerospace enterprise with mixed ownership, and it is also the target enterprise that Oriental Aerospace Port focuses on introducing. Relying on the scientific research strength and resource advantages of the Institute of Mechanics of the Chinese Academy of Sciences and the Aerospace Flight Technology Center of the Chinese Academy of Sciences, China Aerospace Science and Technology has been committed to the research and development and integration of space technology and aerospace vehicles as a platform for the transformation of major national scientific research projects, as well as the transformation and provision of technological achievements. Aerospace launch service. The Lijian-1 rocket project also adds a brand-new name card to the Oriental Space Port, which will surely promote the construction of the Oriental Space Port to take a solid step forward.

Before July 29, 2024, the static test of the composite cabin of the “Lijian-2” liquid launch vehicle was successful. This test mainly verifies whether the structural scheme meets the design requirements under the maximum design load and assesses the feasibility of the composite scheme. Since the beginning of this year, the development of the “Lijian-2” rocket has been rapidly advanced and is steadily moving towards its first flight.

Three cores in parallel, bundled recycling

“Lijian-2” is a medium-sized cryogenic liquid carrier rocket developed by the China Aerospace Science and Technology Corporation (CAS Space). It adopts a two-and-a-half-stage configuration. The take-off stage adopts a CBC configuration, in which the core first stage and two core first stage module boosters are bundled side by side, and the core second stage is connected in series on the core first stage.

The first stage of the rocket core is equipped with three YF-102 liquid oxygen-kerosene engines, adopting an open gas generator cycle and a pump-front swing design, supporting double swing of ±6°, a single sea level thrust of approximately 85 tons (835 kN), a sea level specific impulse of 275.5 seconds, and a thrust-to-weight ratio of not less than 130; the two boosters are configured basically the same as the first stage of the core; the second stage of the core is equipped with a YF-102V liquid oxygen-kerosene engine with a thrust of approximately 72 tons (710 kN), which can achieve 55%~100% variable thrust, a vacuum specific impulse of 320 seconds (throttling)~330 seconds, and support repeated starts for no less than 2 times.

The entire rocket of “Force-2” is 52 meters high. The diameters of the core stage, core stage and booster are all 3.35 meters. It is equipped with a fairing with a diameter of 4.2 meters. The take-off mass is 625 tons and the take-off thrust is 766 tons. Its low-Earth orbit (LEO) carrying capacity is 12 tons and its 500-kilometer sun-synchronous orbit (SSO) carrying capacity is 8 tons.

The ultimate goal of “Force Arrow II” is to become a reusable launch vehicle, realize multiple recovery and reuse of the core stage and boosters, and support reuse more than 20 times. The three-core parallel launch stage of the arrow will implement cluster separation and cluster recovery. The convenience lies in that it only needs to be equipped with a flight control system and a recovery and landing system, the latter includes a set of sang rudders and a set of landing legs. Two of the four sang rudders are distributed in the core stage, and the other two are distributed in the boosters. Two of the four landing legs are distributed in the core stage, and the other two are distributed in the boosters. According to the plan, “Force Arrow II” will realize the recovery of the core stage and booster modules in 2028.

The first flight is to launch a cargo spacecraft

Since the proposal, the “Lijian-2” has undergone major changes in the plan. The current design is very different from the previous single-stage plan, and the first flight has been postponed for several years. According to the plan, in August 2025, the “Lijian-2” will make its first flight at the No. 2 station of the Wenchang Commercial Space Launch Site, and the takeoff stage will not be recovered.

The first flight mission of “Lijian-2” carried a heavy-duty cargo spacecraft. The cargo spacecraft was developed by the Microsatellite Innovation Institute of the Chinese Academy of Sciences. In the bidding for the overall plan of the low-cost cargo transportation system for the Chinese space station released by the China Manned Space Engineering Office in May 2023, the Chinese Academy of Sciences and the Satellite Innovation Institute jointly carried out ship-rocket joint demonstration and key technology research, and carried out the “ship-rocket-cargo” integrated space-to-earth transportation system plan design. With the ship-rocket collaborative solution of the low-cost cargo spacecraft and the “Lijian-2” rocket, it was successfully shortlisted in the bidding and entered the detailed design stage of the plan.

The launch mission of the low-cost cargo spacecraft to be carried out by the Lijian-2 rocket is the first time that a Chinese commercial aerospace enterprise has participated in the development and launch of a low-cost cargo transportation project for the Chinese space station. If it is finally selected, the Lijian-2 will become China’s first commercial rocket to carry out manned space missions, which will also be a recognition of the reliability of the Lijian-2.

Build your own advantages by networking for the constellation!

As a commercial aerospace enterprise, China Aerospace Science and Technology is targeting the vast commercial space launch market, especially the low-orbit satellite constellation launch service market. my country’s currently planned low-orbit constellation contains tens of thousands of satellites, which require launch vehicles to provide large-capacity, high-frequency, low-cost, and high-reliability launch services. Compared with China’s liquid commercial rockets of the same level, the “Lijian-2” rocket does not have an advantage in capacity, but it can work hard on high frequency, low cost, and high reliability.

Create high-frequency launches. At the Hainan Commercial Space Launch Center in China, two launch stations have been built. Both stations have a designed launch capacity of 16 times per year. Station 2 is a general-purpose station that needs to support the launch of more than a dozen types of rockets, which is far from enough for high-frequency launches. In addition to using Hainan Commercial Launch Station 2, China Science and Technology Aerospace is building a dedicated technical preparation plant at the Jiuquan Satellite Launch Center and is about to build a dedicated launch station for the “Lijian-2” rocket. Based on self-built stations, China Science and Technology Aerospace will be able to achieve dozens of launch frequencies per year.

Achieve low cost. “Lijian-2” uses a lot of mature technologies. The main power is all YF-102 series engines. All stages use mainstream tank modules with a diameter of 3.35 meters. It uses the same avionics system as “Lijian-1”. The application of mature and common technologies means that costs can be greatly reduced. At the same time, simplifying the design is another important way to control costs. For example, the core second-stage box section takes into account the functions of the traditional liquid rocket instrument cabin and cancels the core second-stage instrument cabin, which simplifies the cabin structure and saves materials.

Achieve high reliability. While applying mature and general technologies, the power system and avionics system adopt redundant design, and the separation scheme is simple, making the rocket highly reliable. For example, the launch stage of the rocket is equipped with 9 YF-102 engines, with a single sea level thrust of about 85 tons, a total rocket takeoff thrust of 766 tons, a takeoff mass of 625 tons, and a thrust-to-weight ratio of 1.23, achieving a large power redundancy, and can complete the launch mission in the event of one engine failure.

Building a stronger model

After my country’s low-orbit constellation enters the large-scale networking period, the intensive networking and launch of tens of thousands of satellites requires a large-scale reusable launch vehicle, but the current “Lijian-2” has obviously insufficient capacity.

Based on the Lijian-2, China Aerospace Science and Technology will develop a more powerful “Lijian-2” heavy-lift launch vehicle (called “heavy”, but actually large). The latter is based on the former and adds two core-stage module boosters to achieve five cores in parallel (5CBC). The “Lijian-2” heavy-lift rocket is 56 meters high, with optional fairings of 4.2 meters and 5 meters in diameter, a takeoff mass of 913 tons, a low-Earth orbit (LEO) capacity of 22 tons, and a 500-kilometer sun-synchronous orbit (SSO) capacity of 15 tons. The core stage and booster can be reused more than 20 times.

In general, the “Force-2” will be a high-quality rocket that can meet market demand to a large extent. Facing the needs of constellation network launches, with its advantages of high frequency, low cost and high reliability, the “Force-2” is bound to become one of the main near-Earth “flights”.

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