The Chinese conducted the maiden launch of the Long March 7 rocket on Saturday. The launch took place at 12:00 UTC, which also involved the inauguration of is new Wenchang Space Launch Center, located at the Hainan Island. The main payload for this mission was a scaled-down version of a next generation crew vehicle that was successfully recovered in Inner Mongolia after a short orbital flight.
Long March 7 Debut:
The development of the Chang Zheng-7 (CZ-7) (Long March-7 – LM-7) launch vehicle begin in May 2010, then designated the Chang Zheng-2F/H (CZ-2F/H).
The new launcher is China’s new-generation medium-lift orbital launch vehicle, developed by the China Academy of Launch Vehicle Technology (CALT).
The initial project was to be a modernized version of the CZ-2F, to be used on unmanned and manned flight missions in the China Manned Space Program.
LM-7 will be mainly used for orbiting the new Tianzhou cargo vehicle for the Tiangong-2 program, which will progress into the modular Tiangong space station. Its future role will be to replace the hypergolic launchers of the LM-2, LM-3 and LM-4 rockets.
Initial flights of the new launch vehicle will be classed as test launches before achieving an operational capability, at which point it will be qualified for manned launches.
The new rocket is powered by the newly developed YF-100 – the first stage using two engines and strap-on boosters using a single engine each, and a YF-115 driven second stage using four engines. Both stages run on kerosene and liquid oxygen.
The YF-100 development began in 2000 at the Academy of Aerospace Liquid Propulsion Technology.
The engine was certified by the State Administration of Science, Technology and Industry for National Defence (SASTIND) in May 2012.
It is a staged combustion cycle engine developing 1,199.19 kN at sea-level with a Isp of 2,942.0 N.s/kg (vacuum values are: thrust 1,339.48 kN; Isp 3,286.2 N.s/kg). The YF-100 will also be used on the Long March 5 and Long March 6 rockets.
The YF-115 is it also a staged combustion cycle engine, which develops 176.5 kN of thrust in a vacuum.
The engine was developed by the Academy of Aerospace Liquid Propulsion Technology and will also be used on the Long March 5 and 6 launch vehicles.
The basic configuration of the LM-7 involves a two stage launch vehicle equipped with four strap-on boosters. The total length is 53 meters with a diameter of 3.35 meters and a span of 10.05 meters. It sports a gross mass of 597,000 kg.
At launch, the rocket develops a lift-off thrust of 7,200 kN and is capable of orbiting 13,500 kg into a 400 km LEO and 5,500 kg into a 700 km SSO.
China’s new space launch center:
The rocket’s components are transported to the launch site from the industrial city of Tianjin using two dedicated cargo ships, the Yuanwang-21 and the Yuanwang-22. The components are offloaded at the Qinglan seaport serving the Wenchang Space Launch Centre.
The center is located in the northeast corner of the Hainan Island on the southern coast of China.
The new launch complex brings a larger versatility that isn’t provided by the other three launch sites. Wencheng provides an increase in performance for the launch vehicles gained from the Earth’s rotational speed because is closer to the Earth equator. This reduces the amount of propellants required for the satellite’s maneuver from the transit orbit to GEO.
The launch vehicle can also fly from the launch site to the southeast direction into the South Pacific, avoiding the possibility of rocket debris falling into any populated area.
The center is equipped with two launch complexes.
Launch Complex LC101 is used for the Long March 5 launch vehicle family while Launch Complex LC201 is used for the Long March 7 launch vehicle.
Both pads are similar and are equipped with a fixed umbilical tower, underground flame deflector trenches and ducts. Similarly to what happens at the other Chinese launch centers, the umbilical towers have swing arms to allow technicians to access and inspect the launch vehicle and payload.
The launch pads are served by two vehicle assembly and integration buildings. Launch Complex LC101 is served by Building 501 while Launch Complex LC201 is served by Building 502. Each building is 99.4 meters tall permitting the assembly and testing of the launch vehicle in a full, vertical stacked position.
This is a new approach to the launch vehicle preparation for flight, because at the other Chinese launch centers the launchers are stacked and tested for flight at the launch platforms.
After being stacked at the vehicle assembly and integration building at the top of a mobile launch platform, they are rolled to the launch pad. The journey takes several minutes to cover the 2,800 meters separating the vehicle assembly and integration buildings, and the launch pads.
After arriving at the launch pads, the mobile structure is then placed above the flame trench and the necessary umbilical connections between the fixed structures and the mobile platform are established.
Inaugural Payload:
The primary payload on board the inaugural launch of the Long March-7 was a prototype capsule for the future next generation crew vehicle (NGCV).
This capsule was later confirmed to have successfully re-entered and landed. It was recovered and will be transported back to the launch center.
Other payloads involved were a cubesat, a block of ballast and two other small satellites: ‘ADRV’ and ‘BPV’.
Based on the veteran Soyuz Russian design, the Shenzhou manned space capsules will serve the next generation of Chinese space stations. The Tiangong-2 space station – to be launch at the end of 2016 – and the modular Tiangong space station, with orbital construction scheduled to start in 2018.
For the future, China is aiming for more ambitious with its projects and missions, to the point Shenzhou will not fulfil the role of a next generation manned crew vehicle.
As such, Chinese engineers have begun the development of a new vehicle that can carry the hopes of future Chinese space explorations and foster ambitions of missions to the Moon and beyond.
A recent paper defined the roles for the future NGCV, with the goal of ferry flights to and from the space station in the LEO, exploration missions to Lagrange Points of the Earth-Lunar System, manned Lunar missions, Near Earth Asteroids missions – and even manned Mars missions.
The “Concept Definition of New-Generation Multi-Purpose Manned Spacecraft” cited the future Chinese manned vehicle would be able launching 2 to 6 crew members and noted two versions of the spacecraft.
For missions to LEO, Near Earth Asteroid and Mars, the capsule would be a 14-tonne range vehicle, while for lunar landing missions the spacecraft would be a 20-tonne capable vehicle.
Based on the concepts of future lunar landing and deep space missions, the NGCV is required to be capable of loitering independently in orbit for at least 21 days, or for as long as two years if docked with the space station.
The crew module is a blunt cone shape in appearance, adopting a two-module arrangement, with a cylindrical-shaped service module at the aft. A docking port and associated docking sensors are fitted to the front-end of the crew module.
The spacecraft can be fitted with two different service modules, with alternate propulsion systems and propellant capacities.
The thermal protection shield of the future crew vehicle will be made from a light weight ablator material. The new vehicle will be recovered from an ocean splashdown location near the Earth equator off the Chinese coast, while retaining a land recovery capability as a backup.
The Star of Aoxiang is a CubeSat-12U picosat mission set to investigate polarization patterns for navigation technology validation.
The 33 kg mass satellite will operate in a 380 km altitude orbit with a 40 deg inclination and will include anti-radiation technology.
(Images via China 24, Various Chinese News streams, NSF Members).