The TH-12 (Chinese: 天火-12; pinyin: Tiānhuǒ-12, lit. Sky Fire 12) is an oxidizer-rich gas-generator cyclerocket engine burning LOX and kerosene under development by Space Pioneer. The TH-12 utilizes 3D printing and has the highest target thrust among all commercial rocket engines in China. The engine features deep throttling for reusability, re-ignition, thrust vectoring, and multi-mode starters.[2]
Space Pioneer proposed the TH-12 engine for its Tianlong-3 launch vehicle.[3] Engine development was underway in December 2020, with the first gas generator test performed in September 2022. In November 2022, a full-stage developmental TH-12 engine successfully completed its first static fire test.[4]
On July 24, 2023, the TH-12 engine, in the flight configuration of the first Tianlong-3 rocket, successfully completed a full-duration hot fire test at rated conditions for a single burn duration of 100 seconds, accumulating a total test duration of 200 seconds. This test demonstrated that the engine met the flight requirements for the Tianlong-3 rocket.[5]
In early January 2024, the TH-12 engine completed a calibration hot fire test for the first flight batch, subjecting the engine to a 50-second process verification test at rated conditions, demonstrating rapid startup, smooth operation, and normal shutdown.[6] Later that month, the TH-12 engine underwent a spot check hot fire test for the first flight batch, fully simulating the flight conditions of the inaugural Tianlong-3 launch. The test involved 6 consecutive ignitions of the engine without removal from the test stand, accumulating a total test duration exceeding 1,000 seconds, with the single engine operating time surpassing the planned flight duration by a factor of 6.[7]
