Tianzhou-1 – China set to debut cargo resupply to Tiangong-2
April 19, 2017 by Rui C. Barbosa
China is set to take another significant step on the road towards a permanent presence in space when a Launch March 7 (TZ-1) launches Tianzhou-1 – the first Chinese logistics cargo vehicle. The launch is set to take place at 11:40:45 UTC on Thursday from the LC201 Launch Complex at the Wenchang Space Launch Center.
Tianzhou-1:
A successful mission for the Tianzhou-1 (TZ-1) vehicle will demonstrate China’s capability of cargo transport and refueling of an orbiting space station.
With a launch mass or nearly 13,000 kg, Tianzhou-1 is the heaviest cargo ever to be orbited by a Chinese launch vehicle.
The main objective of Tianzhou-1 mission is to conduct the on-orbit refueling of the Tiangong-2 space station.
During the mission,
the new vehicle will make three rendezvous attempts with Tiangong-2. Combined operations with the Tiangong-2 / Tianzhou-1 orbital complex will take place over two months. At the end of this period, Tianzhou-1 will separate from Tiangong-2 and will initiate an autonomous orbital mission for three months to carry out experiments and tests during that period of time.
At the end of the mission, Tianzhou-1 will make an automatic destructive reentry into Earth’s atmosphere.
A cargo freighter for the future:
The Tianzhou (‘Heavenly Vessel’) cargo freighter has a payload capacity of 6,500 kg (including 2,000 kg of propellant), It has a length of 10.6 meters and a maximum diameter of 3.35 meters.
The new vehicle, developed on the basis of the Tiangong-1 space station, will be capable of executing fully automated rendezvous maneuvers and docking with Tiangong-2 and with the future modular Tiangong station.
Like the Russian Progress cargo vehicles, future crews and mission control will be able to override the approaching vehicle.
Transporting diverse cargo and fuel to the orbital outposts, Tianzhou will also be used to discard trash and execute autonomous missions after undocking. At the end of the mission, the vehicle will be discarded via a destructive reentry into the Earth’s atmosphere.
The second Tianzhou cargo vehicle is scheduled for launch in 2019, after the launch of the Tiangong space station core module (the Tianhe-1) using a Long March-5B rocket from Wenchang. The docking of Tianzhou-2 with the Tianhe-1 module will open the door for
the launch of the Shenzhou-12 crew mission.
The Long March-7:
The development of the Chang Zheng-7 (CZ-7) (Long March-7 – LM-7) launch vehicle began in May 2010. It was originally designated Chang Zheng-2F/H (CZ-2F/H).
The new launcher is China’s new-generation medium-lift orbital launch vehicle developed by China Academy of Launch Vehicle Technology (CALT). The initial project was to be a modernized version of the CZ-2F to be used on the unmanned and manned flight missions in China’s “Manned Space Program”.
LM-7 will be mainly used for orbiting the new Tianzhou logistics cargo vehicle for the Tiangong-2 and to the modular Tiangong space station, but in the future, will replace the hypergolic launchers of the LM-2, LM-3 and LM-4 rocket range.
Initial flights of the new launch vehicle will be seen as test launches before achieving an operational capability when it will also be used for crewed launches.
The LM-7 is a two stage launch vehicle equipped with four strap-on boosters. Total length is 53.00 meters, diameter is 3.35 m and a span of 10.05 m, with a gross mass of 597,000 kg. At launch it develops a lift-off thrust of 7,200 kN. The rocket is capable of orbiting 13,500 kg into a 400 km LEO and 5,500 kg into a 700 km SSO.
Rocket 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 then offloaded at the Qinglan seaport serving the Wenchang Space Launch Centre.
The new rocket is powered by the newly developed YF-100, with the first stage using two engines and strap-on boosters using a single engine each. It includes the YF-115 on the second stage using four engines, using kerosene as fuel and liquid oxygen as oxidizer.
The development of the YF-100 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 Defense (SASTIND) in May 2012.
It is a staged combustion cycle engine producing 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 CZ-5 and CZ-6 launch vehicles.
The YF-115 is it also a staged combustion cycle engine. It develops 176.5 kN in a vacuum.
Wenchang, China’s new space launch center:
Wenchang Space Launch Centre is located in the northeast corner of the Hainan Island on the southern coast of China.
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, the rocket is 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 ahead of the flow to launch.
The new launch complex provides additional versatility that isn’t available at the other three launch sites. Wencheng also allows for an increase in performance for the launch vehicles gained from Earth’s rotational because is closer to the Earth equator. This reduces the amount of propellants required for the satellite’s maneuvers from the transit orbit to GEO.
Also, the launch vehicle can fly from the launch site to the southeast direction into the South Pacific, avoiding the possibility of rocket debris falling into any populated area – which has occurred during numerous Chinese launches.
https://www.nasaspaceflight.com/2017/04/tianzhou-1-china-debut-cargo-resupply-tiangong-2/
What is the Tianzhou 1 and why does it matter in China’s ambitious space mission?
Spacecraft will act as supply vessel as part of ambitious plans to build a space station orbiting the Earth
PUBLISHED : Thursday, 20 April, 2017, 1:01pm
UPDATED : Thursday, 20 April, 2017, 1:02pm
Stephen Chen
Tianzhou-1, China’s first space cargo ship, is due to be launched on Thursday evening from a space centre in southern Hainan province.
The craft will be put into orbit by a Long March-7 Y2 carrier rocket blasting off from Wenchang Space Launch Centre.
China to launch first cargo spacecraft Tianzhou 1
The Tianzhou-1 forms part of China’s ambitious plans to build an orbiting space station. Construction of the project is due to begin next year and be completed by about 2020.
On its maiden flight, the cargo craft will dock with the small, orbiting Tiangong-2 space laboratory.
The Tianzhou will ultimately be used to carry supplies to up to six astronauts living on board the space station.
Some will spend up to a year living and working in orbit and they will need constants supplies of basics such as food and water.
China’s 30-year long march to its biggest ever rocket launch
The space station will also need to be refuelled regularly to resist the Earth’s gravitational pull, or to change course to avoid collisions with orbiting space junk and debris.
Tianzhou-1 is an unmanned supply ship. It will dock with the space station automatically in futures missions, unload its cargo and fuel, then leave with waste before plunging into the atmosphere to burn-up.
Dr Yang Yuguang, secretary general of the International Space Transport Association and a senior researcher in the Chinese space industry, said China’s space station will not be able to function over the long term without the support of a large, advanced space freighter.
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“This is the ultimate reason why China is building up a cargo fleet,” he was quoted as saying by the
People’s Daily.
Tianzhou-1 is just over 10 metres high, about the height of a three-story building and is the single largest spacecraft China has built.
Its solar wings, when fully extended, match the width of a basketball field. It is larger than the Tiangong space laboratory it will dock with during this month’s mission.
The cargo craft can carry a payload of up 6.5 tonnes, twice that of vessels built by Russia and the United States, according to Chinese scientists.
Japan has developed a craft of a similar size, but it needs a robotic arm to dock with the International Space Station. The European spacy agency developed a freighter that could carry a larger load, but it is no longer in service.
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Morris Jones, a space expert based in Australia, said the cargo ship was a great achievement for China.
“Only Europe, Russia and China have developed freighters that can refuel a space station. America has not done this,” he said.
Two cargo ships under development or in service in the US, the Cygnus by Orbital Sciences Corporation and Dragon by SpaceX, have a single-compartment design with no room for fuel.
“Tianzhou is a large spacecraft with more volume than freighters from the USA and Russia. It can thus carry more cargo than some other freighters,” said Jones.
“Different versions are designed to carry different combinations of pressurised cargo, which goes straight to the interior of the space station, and unpressurised cargo, which is unloaded in open space and attached to the exterior of the space station,” he added.
The Chinese space authorities also say Tianzhou-1 is the lightest space cargo ship ever made.
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Bai Mingsheng, chief designer of the craft, told China’s state television: “The carrying capacity of Tianzhou is designed to match the scale of the space station, to meet the principle of the highest carrying capacity with the lowest structural weight.”
A significant part of the weight reduction comes from the widespread use of new alloys and carbon fibres, according to state media reports.
Zhou Jianping, chief designer of China’s manned space programme, said the first flight of the Tianzhou-1 was a milestone in China’s ambitious space missions.
“The success of Tianzhou means the official completion of the space laboratory phrase. We can start building the space station from now on,” he told mainland media.
http://www.scmp.com/news/china/poli...ianzhou-1-and-why-it-matters-chinas-ambitious
China to launch first cargo spacecraft Tianzhou 1
PUBLISHED : Thursday, 20 April, 2017, 12:53pm
UPDATED : Thursday, 20 April, 2017, 1:05pm
China will launch its first cargo spacecraft on Thursday, state media said, taking another step towards its goal of establishing a permanently manned space station by 2022.
President Xi Jinping has prioritised advancing China’s space programme to strengthen national security and defence.
What is the Tianzhou 1 and why does it matter in China’s ambitious space mission?
The Tianzhou-1 cargo resupply spacecraft will be launched at 7.41pm (1141 GMT), borne aloft on a Long March-7 Y2 rocket from the Wenchang Satellite Launch Centre in the southern island province of Hainan, the Xinhua news agency said on Wednesday.
It is designed to dock with the Tiangong 2 space laboratory, or “Heavenly Palace 2”, where two astronauts spent a month in space last October in China’s longest ever manned space mission.
The mission will provide an “important technological basis” for the construction of China’s space station, Xinhua said.
What the Chinese astronauts did during their month-long space mission on Tiangong-2
The spacecraft can carry 6 tonnes of goods, 2 tonnes of fuel and can fly unmanned for three months, state media have said.
Despite the advances in its space programme for military, commercial and scientific purposes, China still lags the United States and Russia.
Why China decided to give 49-year-old astronaut record third mission
In late 2013, China’s Jade Rabbit moon rover landed on the Moon to great national fanfare, but ran into severe technical difficulties.
The US Defence Department has highlighted China’s increasing space capabilities, saying it was pursuing activities aimed at preventing other nations from using space-based assets in a crisis.
http://www.scmp.com/news/china/poli...hina-launch-first-cargo-spacecraft-tianzhou-1
