At 22:25 on the evening of November 30, 2024, Beijing time, the Long March 12 Yaoyi rocket was successfully launched from Station 2 of the Hainan Commercial Space Launch Site. The biggest feature of this launch is the “new launch station + new rocket configuration + new engine”.
The Long March 12 rocket was developed by the chief executive of the Eighth Academy of Aerospace Science and Technology. It has a two-stage configuration without boosting. The diameter of the rocket body is 3.8 meters. It comes standard with 5.2-meter and 4.2-meter fairings. This time it is equipped with a 5.2-meter fairing. The core first stage is equipped with 4 YF-100K liquid oxygen kerosene engines (thrust 1250 KN), and the core second stage is equipped with 2 YF-115 liquid oxygen kerosene engines (thrust 180 KN). The LEO transport capacity of the Long March 12 is no less than 10 tons, and the SSO (700km) transport capacity is no less than 6 tons. In terms of transport capacity, the LEO transport capacity of the Long March 12 has exceeded the Chang 2F, and is second only to the Chang 5 and Chang 7, but the Chang 12 is a polished rocket.
The Long March 12 core uses a YF-100K engine as the first stage. It adopts an oxygen-rich staged combustion cycle, uses a pump to swing, supports two-way swing of ±8 degrees, has a variable thrust capability of 65% to 105%, has a sea level thrust of about 128 t, and a sea level specific impulse of 301.84 s. The second stage of the core uses a YF-115 engine, which adopts an oxygen-rich staged combustion cycle, supports two-way swing of ±4 degrees, supports 80% to 100% variable thrust, has a vacuum thrust of about 18 tons, a vacuum specific impulse of about 342 s, and can be started twice.
Before the Long March 12, my country limited the diameter of the rocket to 3.35 meters because of the transportation issues at the inland launch site. Although the Long March 5 broke through this limitation and reached a core diameter of 5 meters, the Long March 5 can only be transported to Wenchang for launch by sea and cannot be transported to an inland launch site for launch. Long March 12 is equipped with four YF-100K liquid oxygen kerosene engines with a diameter of 3.8 meters. In order to be transported by rail, Long March 12 made repeated demonstrations during the development process and conducted a large number of transportation tests with the railway department. In the future, it can not only be transported by sea to Wenchang for launch, but also transported by rail to other launch centers for launch.
The innovation of Chang Twelve lies in the optimization of the rocket’s aspect ratio. The rocket’s aspect ratio is a very important technical parameter, which directly affects the stability of the rocket recovery process. Previously, my country’s rockets had a diameter of 3.35 meters. The rockets were thin and long, making attitude control difficult. Chang Twelve increased the rocket diameter to 3.8 meters. After increasing the rocket diameter, it is easier to control the stability of the rocket. In addition, after the rocket diameter is increased, the matching relationship between the rocket diameter and the number of engines is also optimized. It will also be easier to increase the rocket capacity in the future. This is very important for the future development of reusable rockets.
This launch used Hainan Shangfa No. 2 station. Hainan Shangfa No. 2 station is a universal launch station. It adopts the three-level test and launch mode and is compatible with 19 rockets. Currently, the only one that is ready for launch is the Long March 12. This launch is a very important milestone. It is the first time that our first and only commercial space launch site has undertaken a launch mission.
Cheer for our country’s aerospace industry!
