Long March 10

Long March 10 (Chinese: 长征十号), also known as the “Next Generation crewed launch vehicle” (Chinese: 新一代载人运载火箭), and previously and unofficially as the “921 rocket” (Chinese: 921火箭) or the "Long March 5G" (a development of the Long March 5), is a Chinese super-heavy carrier rocket for crewed lunar missions that is currently under development. The nickname "921" refers to the founding date of China's human spaceflight program. In 2022, the first flight was targeted for 2027. In April 2024, it was announced that program development was complete.

The standard Long March 10 will be capable of lifting 70 tonnes into low Earth orbit (LEO) and 27 tonnes into trans-lunar injection trajectories.

There are also plans for a two-stage variant without boosters, the Long March 10A, which is designed primarily for future low Earth orbit crew and cargo transport to the Tiangong space station. It will be partially reusable and capable of lifting at least 14 tonnes into LEO. In November 2024, it was reported that the first flight of the CZ-10A variant is targeted for 2026.

The Long March 10 is a human-rated super heavy launch vehicle designed to launch China's Mengzhou crewed lunar spacecraft and its future Lanyue crewed lunar lander, as part of its crewed space program, codenamed Project 921. Its notional debut was at the 12th China International Aviation & Aerospace Exhibition in November 2018, where it was announced that the China Academy of Launch Vehicle Technology (CALT) is developing a vehicle with a lunar orbit capacity of up to 30 tons, meeting the requirements for crewed lunar exploration. Documents and presentations in subsequent years depicted modified Long March 5 configurations known as CZ-5DY (pinyin abbreviation for 'Deng Yue' 登月 or 'lunar landing'), CZ-5G, and CZ-5H.

In February 2023, at the "30 Years of China's Manned Spaceflight" exhibition held at the National Museum of China, a model of the next-generation crew launch vehicle was labeled as "Long March 10." An article later published by China Aerospace Science and Technology Corporation also used the term "Long March 10" to refer to the rocket.

The standard variant of the vehicle consists of two boosters, first, second and third stage cores, escape tower, and fairing. The first-stage core and the two boosters each have a diameter of 5.0 meters and are equipped with 7 YF-100K engines (for a total of 21 operational engines at liftoff). The second-stage core has a diameter of 5.0 meters and is equipped with 2 YF-100M engines. The third-stage core has a diameter of 5.0 meters and is equipped with 3 YF-75E engines. The vehicle's total length is approximately 90 meters, with a liftoff weight of 2,187 tons. The diameter of its core stage is the same as that of the Long March 5, but its height is about one-third taller.

The rocket has a payload capacity of 70 tonnes to low Earth orbit and at least 27 tonnes to a trans-lunar injection trajectory. The proposed crewed lunar mission would use two Long March 10s; the crewed spacecraft and the lunar landing stack would launch separately and subsequently rendezvous in lunar orbit, prior to a crewed lunar landing attempt. The development of the rocket along with relatively detailed specifications were announced at the 2020 China Space Conference.

The Long March 10A is a single stick variant with only 2 stages; it has 7 YF-100K engines on the first stage and a single YF-100M engine on the second stage, This variant is designed for low Earth orbit crew and cargo flights; it is part of the Chinese space program's plan to increase lift capacity, explore reusability, and phase out hypergolic fuels for its carrier fleet. The 10A will have a capability to low Earth orbit of at least 14 tonnes when the first stage is recovered and at least 18 tonnes when used in a completely expendable arrangement; it will use kerosene as fuel and liquid oxygen as the oxidizer. The rocket's first stage will have restartable engines and grid fins to enable reuse after stage recovery. First stage landing and recovery will employ "tethered landing devices" in lieu of landing legs; this tethered system involves the deployment of "hooks" by the stage which would be caught by a tensioned wire system on the ground.