China launches TianGong-1 to mark next human space flight milestone
After becoming the third nation to master the human spaceflight, China has made its next step in human space exploration with the launch of the unmanned space module TG-1 TianGong-1. Lift-off was on schedule at the opening of the launch window at 13:16UTC on on Thursday using a Long March 2F/G (T1) launch vehicle. Launch took place from the SLS-2 Launch Pad at the Jiuquan Satellite Launch Center.
The TianGong-1 module is the rudiment of China’s space station and is an experimental space laboratory. The new module will be mainly used to carry out the rendezvous and docking test, as well as the mastering of the technologies related to rendezvous and docking and accumulate the experience for the construction, management and operation of a space station.
After passing its production certification, TianGong-1 arrived at the launch site via railway to undergo its final testing. Its launch vehicle was delivered on Jiuquan Satellite Launch Center on the morning of July 23. On August 17 the technicians conducted the first launch rehearsal.
Launch was originally expected to take place on August 30. However, the SJ-11 ShiJian 11-04 loss – due to a CZ-2C Chang Zheng-2C second stage failure on August 18 – led to a delay for the space module launch.
After an investigation commission detected the cause of the failure, Chinese space specialists decide to move forward with the TG-1 launch, realigning the schedule for the September 27 – 30 launch window, with a preferred launch date of September 27.
The launch vehicle, integrated with the TianGong-1, was transported to the launch pad on September 20. However, the launch was to be delayed to September 29 or September 30. due a weather forecast that showed the arrival of a cold air mass at the Jiuquan launch center.
On September 25 the launch technicians conducted a full ground simulation to ensure that the module and its launch vehicle were prepared for the actual launch, followed by the September 26 conducting of final preparations for launching China’s first space laboratory module.
This mainly involved Chinese engineers putting in place pipes and cables that are to be used to fuel the rocket.
The TianGong-1 launch mass is documented at 8,506 kg for 10.40 meters module. It is composed of two cylindrical sections with a docking port on its front-end. The two modules are known as the experimental module and the resource module.
The 3.35 meter experimental module is composed of a enclosed front cone shaped section, cylindrical section and rear cone shaped section. On the front end of the experiment module there are the docking mechanism and the measuring and communication equipment, which is used to support the rendezvous and docking with future spaceships.
The experimental module is where the taikonauts will live and work, with 15 cubic meters of space to move around in. This section is also equipped with two sleeping sections with adjustable lighting systems, exercise equipment, entertainment systems, visual communications devices and control systems.
A paint scheme inside the module will aid the taikonauts, as a way of maintaining their sense of direction. The module’s inner walls will be in two colours, one commonly associated with the sky and one with the ground.
The 2.8 meter resource module will supply the power necessary for flight – containing two solar panels, propellent tanks, and other systems. TianGong-1 will stay in orbit for two years.
After a period of orbital testing and checkouts of the TianGong-1, China will be ready for the launch of the SZ-8 Shenzhou-8 unmanned spacecraft with a CZ-2F Chang Zheng-2F (Y8) launch vehicle. Launch is now expected to take place on November 1. Docking would occur after all the systems are verified on both vehicles.
The TianGong-1 spacecraft is expected to stay in orbit for two years and rendezvous and dock with three different spaceships. Shenzhou-8, Shenzhou-9 and Shenzhou-10 will make similar missions, while at least one of the two is to be manned. The taikonauts will stay on board for a maximum of two weeks.
Before the taikonauts ingress TianGong-1, the conditions inside its experimental module will be adjusted to ensure they can live in an environment that contains enough oxygen, moisture and heat to be safe.
TianGong-1 will be placed on a near circular 350 km orbit after two orbiting manoeuvres. Prior to the Shenzhou-8 launch, this orbit will be reduced to 343 km. Two days after launch, the docking between the two vehicles will take place.
The mission then calls for TianGong-1 and Shenzhou-8 to remain docked for a period of 12 days, after which a second docking manoeuvre will take place. After another period of docking, the unmanned spacecraft will be put on an autonomous flight and return to Earth.
In the future, the TianGong will be upgraded to a cargo vehicle to service the Mir-class station, with its core module due to launch in 2020. However, before that, China plans to launch the TG-2 TianGong-2 in 2014 (to develop the necessary technologies for water and oxygen regeneration necessary for short-term stay in orbit and to carry out some scientific experiments) and TG-3 TianGong-3 in 2015/2016.
TG-3 will likely be equipped with two docking ports, allowing a permanent residency of the module. TG-3 mission will involve the development of the technologies necessary for medium to long-term orbital stays and to carry out more sophisticated scientific researches and experiments.
The launch vehicle:
TianGong-1 was launched by the CZ-2F/G Chang Zheng-2F/G – otherwise known as the Long March 2F/G – a variant of the launch vehicle usually used for the manned Shenzhou program. The launch vehicle is also known as the CZ-2F Chang Zheng-2F ‘Phase One’.
This launch vehicle, developed by the China Academy of Launch Vehicle Technology under the China Aerospace Science and Technology Corporation, is different from the original ‘Shenjian’ (Devine Arrow) version that was developed from the CZ-2E Chang Zheng-2E launch vehicle, which in turn was based on the proven flight technology of the CZ-2C Chang Zheng-2C launch vehicle.
Conceptual design of the CZ-2E launch vehicle began in 1986, and the vehicle was launched on the world launch services market following a successful test flight in July 1990.
To meet the requirements of the rendezvous and docking mission, the Chang Zheng-2F was put through nearly 170 technical modifications and used five newly developed technologies.
The launch vehicle was transported to the Jiuquan launch center on June 29, where it was put through its paces via technical testing in preparation for launch.
This vehicle will continue to be used for the launch of the TianGong-1 module and the future cargo vehicles until a more powerful launch vehicle is available.
A substantial difference with this rocket is the absence of the launch escape tower, a more bulbous fairing and an improved separation sequence. On this mission the fairing is 12.7 meters long and 4.2 meters in diameter.
Other characteristic of this version is that it is capable of a more precise orbit insertion accuracy. This is possible via the introduction of improved navigation systems and complex guidance system features real-time input to the rocket to orbit parameters, and use GPS data outside the measurement error correction parameters, so as to achieve double redundancy. Also, more propellant is loaded on the boosters, thus increasing the firing time.
Like the CZ-2F, the CZ-2F/G Chang Zheng-2F/G is a two stage launch vehicle that uses four strap-on boosters during the first stage phase. Overall length of the CZ-2F/G is 52.0 meters with a 3.35 meter core stage and a maximum diameter of 8.45 meters.
At launch it has a 493,000 kg mass, being capable of launching 8,600 kg cargoes into a low Earth orbit.
For the CZ-2F launch vehicle, the LB-40 strap-on boosters have a length of 15.326 meters, diameter of 2.25 meters, a gross mass of 40,750 kg and an empty mass of 3,000 kg. Each booster is equipped with a fixed nozzle YF-20B engine that consumes UDMH/N2O4 developing 740.4 kN of sea lever thrust. Burn time is 127.26 seconds.
The L-180 first stage has a length of 28.465 meters, diameter of 3.35 meters, a gross mass of 198,830 kg and an empty mass of 12,550 kg. It is equipped with a YF-21B engine pack that consists of four YF-20B engines that consumes UDMH/N2O4 developing 2,961.6 kN of sea lever thrust. Its burn time is 160 seconds.
The L-90 second stage has a length of 14.223 meters, diameter of 3.35 meters, a gross mass of 91,414 kg and an empty mass of 4,955 kg. It is equipped with a YF-24B engine pack that consists of one fixed nozzle YF-22B main motor with a swivelling vernier four YF-23B engines.
The engines consume UDMH/N2O4 developing 738.4 kN (main engine) and 47.07 kN (vernier) of vacuum thrust. Total burn time is 414.68 seconds (301.18 seconds burn time for the main engine).
This launch was the 147th Chinese orbital launch and lift-off of the Chang Zheng launch vehicle family. It will also marked the 49th successful orbital launch from the Jiuquan Satellite launch Center, and the tenth orbital launch from China this year.
The launch site:
The Jiuquan Satellite Launch Center, also known as the Shuang Cheng Tze launch center, was the first Chinese satellite launch center. It is located in Ejina Banner, Alxa League in Inner Mongolia.
The site includes a Technical Centre, two Launch Complexes, Mission Command and Control Centre, Launch Control Centre, propellant fuelling systems, tracking and communication systems, gas supply systems, weather forecast systems, and logistic support systems. Jiuquan was originally used to launch scientific and recoverable satellites into medium or low earth orbits at high inclinations.
The manned program uses the South Launch Site Pad 921. This was built in the late 1990s and later added with the 603 Launch Platform for unmanned satellite launches. Apart of the launch pads, the launch complex has a technical centre where take place the preparations of the launch vehicle and spacecraft.
The technical center is composed of the launch vehicle processing and vertical assembly building, spacecraft processing buildings, solid rocket motor processing building, buildings for liquid-propellant storage and processing and the launch control center.
For the TianGong-1 launch, the launch site was equipped with an updated computer center, command monitoring systems and increased ability to adapt to changes in mission conditions, as well as the resources to handle both the launch and command duties. An integrated simulation training system for space launching has also been developed for the docking mission.
Engineers also conducted a two-month comprehensive technical check on equipment at the launch site from March to May. The safety and reliability of all the instruments have been significantly improved. Orbital launches from Jiuquan are supervised from the Mission Command and Control Centre that is located in the Dongfeng Space City, 60 km southwest of the satellite launch center.
The umbilical tower is a 75 meter-high steel structure that is designed to service the launch vehicle and spacecraft with electricity, gases and fluids, also providing facilities for pre-launch checkouts and crew entrance / emergency exit. The tower is equipped with a loading crane, a cargo elevator, and an explosion-proof elevator for the mission crew.
In the event of an emergency, a canvas slide escape system is available for taikonauts to exit the launch pad. Power supply and other support equipment are located inside an underground room beneath the umbilical tower.
The umbilical tower comprises a fixed structure and a pair of six-floor rotating platforms. Once the launch vehicle arrives at the launch pad, the rotating platforms are swung around the vehicle to allow the fuelling and final checkout procedures. The umbilical tower also contains an environmentally controlled and protected area for taikonauts to enter the spacecraft.
Rotating platforms are swung open one hour prior to launch. Four swing arms provide connections for electricity, gases and fluids to the launch vehicle, and are retracted few minutes before launch.
The launch vehicle is carried on a mobile launch platform from the vehicle assembly building to the launch pad. The mobile launch platform moves on a 20 meter wide rail track and carries the launch vehicle vertical stack on a maximum velocity of 25 meters/min.
The platform has a length of 24.4 meters, width of 21.7 meters, and 8.34 meters height, weighing 750,000 kg. It takes 60 minutes to complete the 1,500 meter journey to the launch pad.
The first orbital launch took place on April 24, 1970 when the CZ-1 Chang Zheng-1 (CZ1-1) rocket launched the first Chinese satellite, the Dong Fang Hong-1 (04382 1970-034A).
The Chinese human space flight program:
After the secretive Project 714 ‘Shuguang’ program in the 70’s, China started the development of a manned space program in April 1992. This ‘Project 921′ would lead China in the road of the manned spaceflight.
The first mission of the new program took place on November 19, 1999, via the launch of the Shenzhou-1 unmanned spacecraft. This was the first flight test of CZ-2F Chang Zheng-2F launch vehicle, of which the main purpose was to examine the performance and reliability of the launcher, and, by launching an unmanned spaceship, verify key technologies and system design relating to re-entry control, tracking, control, communication, landing and recovery facilities.
The smooth completion of this test was an important milestone in the space history of China, and indicated that China had made major breakthrough in manned space technologies.
The Shenzhou-1 spaceship was the first unmanned test spaceship to be launched under the China’s manned space engineering program. The vehicle was composed of orbital module, re-entry module and propelling module.
The orbital module is the place where the taikonauts live and work; the re-entry module is the control center of the spaceship, whereby the taikonauts get into space and then return to the Earth; the propelling module is also called as power module, which provides power for spaceship in the course of in-orbit flight and return to the Earth.
The total length of three modules was about eight meters, the diameter of the cylindrical section was 2.5 meters, the maximum diameter of the cone-shaped section was 2.8 meters, and the total mass reached 7,755kg.
The launch of this first mission took place at 2230:07UTC on November 19, 1999 from the Jiuquan Satellite Launch Center. Ten minutes after ignition, the spaceship was separated from the rocket, and then accurately entered into the preset orbit.
After the spaceship entered into orbit, the tracking ad control centers on the ground – and the tracking ships in the Pacific Ocean and the Indian Ocean – monitored the spaceship, and also tested the “life guarantee” system and altitude control system.
At 0500UTC on November 20, the ground command center sent the re-entry command to the spaceship, and Shenzhou-1 smoothly landed at the landing site in the middle of Inner Mongolia at 0541UTC. The flight lasted for 21 hours.
The second mission of the program took place January 9, 2001. This test fully examined the adaptability of the overall technical program for engineering and technical programs in each system.
It also carried out the experiments in the fields of space life science, space material, space astronomy and space physics in the microgravity environment, and obtained a lot of data relating to manned flight as well as other data and samples of scientific test.
As planned, the orbital module remained in the orbit for about half a year, so as to carry out the relevant scientific experiments.
According to official sources, the Shenzhou-2 spaceship was the first formal unmanned spaceship of China. As compared with the Shenzhou-1, Shenzhou-2 had its system structure expanded, and its technical performance was improved. The technical appearance of the Shenzhou-2 spaceship is almost the same as that of a manned spaceship.
The launch took place at 1700:06.651UTC. Ten minutes later, the spaceship successfully entered into the preset orbit. The spaceship flew around the Earth for 108 orbits, flew in the space for nearly seven days, and smoothly completed the preset space-related scientific and technical tests.
However, some rumours claim the Shenzhou-2 suffered sever damage during the return to Earth.
The Shenzhou-3 mission took place from March 25 to April 1, 2002. This mission was deemed a success, with every system working normally, and all preset scientific experiments and exploration tasks were carried out without a hitch.
The successful completion of this test indicated that milestone developments had been achieved for the China Manned Space Engineering team, and that China’s manned space technologies had become increasingly mature, as the country pressed forward with the ultimate realization of manned flight.
In addition, the successful completion of this test also indicated that the implementation of space-related scientific and the development of space resources by China had entered into a new phase.
The Shenzhou-3 spaceship was an unmanned spaceship of which the technical overview was the same of that used on the manned spaceship.
Compared with the second flight test, this test was equipped with the escape and emergency rescue functions, with the backup parachute sub-system improved. The carrier rocket had the failure detection function – their version of the Emergency Detection System (EDS) – and escape function, with redundant systems.
Medical monitoring equipment and in-module radiation environment monitoring equipment were installed on Shenzhou-3, along with tests relating to material science, life science and space environment monitoring.
Shenzhou-3 was launched on 1415UTC, and 10 minutes later, the spaceship successfully entered into the preset orbit.
When the spaceship was flying in orbit, the Yuanwan-1, 2, 3 and 4 space tracking ships – distributed in the Atlantic Ocean, the Pacific Ocean and on the Indian Ocean, along with relevant ground tracking and control stations, under the united dispatch of Beijing Spaceflight Control Center – successfully tracked the spaceship.
When Shenzhou-3 reached an orbital position over the South Atlantic during its 107th orbit around the Earth, the Yuanwan-3 ship -which had waited on station – sent the re-entry command.
After receiving the command, the spaceship adjusted itself from flight attitude to re-entry attitude, the re-entry module was separated from the orbital module, before the braking engine was ignited so as to propel the re-entry module towards Entry Interface. The spacecraft landed successfully in the middle area of Inner Mongolia.
The orbital module remained in space, until all subsequent scientific tasks were completed.
From December 39, 2002 to January 5, 2003, the Shenzhou-4 unmanned flight test took place. When the spaceship was flying in orbit, various instruments and equipment on the spaceship all worked normally, allowing for valuable flight test data and scientific materials to be obtained.
As the third formal unmanned spaceship under the China Manned Space Engineering program, the Shenzhou-4 was heavily developed on the previous unmanned flights. Its equipment, function and technical conditions were almost the same as those of manned spaceship.
As for this spaceship, the total length was about 7.4 meters, the maximum diameter was 2.8 meters, and the total mass reached 7,794kg. A solar cell wing was installed on the quadrant II and quadrant IV of the propelling module and orbital module respectively.
The total area of the two solar cell wings on the propelling module reached 24.48 squared meters, and the width of the unfolded wing reaches about 17 meters. The total area of the two solar cell wings on orbital module reached 12.24 squared meters, and the width of the unfolded wing reached about 10.4 meters.
The launch of Shenzhou-4 took place at 1640:03.543UTC on December 39, 2002. As planned, the spaceship flew in the space for six days and 18 hours and flew around the Earth for a total of 108 orbiter.
Four Yuanwang space tracking ships were once again distributed in three oceans for ground tracking and control stations. In space the spaceship successfully completed several hundred actions, including a change of orbit.
At 1116UTC on January 5, 2003, Shenzhou-4 spaceship landed at the landing site in the middle of Inner Mongolia after completing the pre-set space-related tests.
After four successful unmanned tests it was time for the first manned mission. The launch of Shenzhou-5 with the taikonaut Yang Liwei on board took place at 0100:03.497UTC on October 15, 2003. The mission realized the Chinese people’s thousand-year dream of manned flight in space, and was a new milestone for China’s space engineering program.
The purpose of this flight was to fully examine the manned space flight environment, obtain the data relating to the living environment and safety of taikonauts, and fully examine the operating performance, reliability and safety of each system – as well as the coordination of various systems.
The Shenzhou-5 manned spaceship had the ability to carry out automatic return under emergency, manually-controlled return, and return in the second or third day.
Sixteen hours before the launch, the first taikonaut Yang Liwei was selected from the 3-member first taikonaut team, and about 2 hours 45 minutes before the launch, the taikonaut entered into the spaceship.
At 120 seconds after launch, the escape tower separated, with the boosters separating 17 seconds later. The first stage separated at 159 seconds and the second stage ignited. At 200 seconds the fairing separated and at 460 seconds the second stage main engine shutdown. Already in orbit, Shenzou-5 separated at 587 seconds into the mission.
On orbit, the spaceship set up an operating mode and unfolded the solar arrays on the propulsion module to point the Sun. When the flight began the fifth orbit, the spaceship implemented orbital transfer to a 343km circular orbit.
During the flight, the ground kept in very close touch with taikonaut Yang Liwei in order to keep abreast of his physical condition through the physiological telemetry parameters. At the same time Yang Liwei monitored the execution of important commands and the operation of the spaceship during the flight.
Yang Liwei also completed the relevant operations in accordance with the preset procedures. When the flight entered seventh orbit, Yang Liwei showed the national flag of China and the flag of the United Nations in the space.
From 343 km above the Earth, Yang Liwei sent a greeting to people all over the world, said hello to all comrades engaged in manned space engineering program, along with extending his gratitude to the people all over the country for their care and support.
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On the eighth orbit, Yang Liwei also talked with his family members. He wrote down in his workbook that: “For the peace and advancement of the human beings, the Chinese people come to space!”
Shenzhou-5 autonomously orbited the earth 14 times. On the last orbit, the ship received accurate return data from the ground and started to run the return program.
The first move was to turn 90 degrees in yaw to separate the orbit module. The second was to turn another 90 degrees in yaw and activate the retro-motor. Lastly, the propulsion module was separated from the re-entry module at the altitude of 145 km.
The re-entry module re-entered the atmosphere and passed through “black out area”, before descending towards the main landing site. The parachute was opened, decreasing the vehicle’s velocity. Around one meter above the ground, four landing engines were activated.
At 2223UTC on October 15th, 2003, the re-entry module landed safely on the grassland of central Inner Mongolia. After 21 hours and 23 minutes flight, Yang Liwei egressed the re-entry module on his own.
The orbital module remained in the orbit for 707 days, carrying out a large amount of scientific experiments and accumulating experience for the development and manufacturing of long-life spacecraft.
The second Chinese manned spaceflight took place on October 12, 2005 with the launch of Shenzhou-6.
The main purpose of this mission was to master the technology relating to a “multi-person and multi-day” orbital flight, as well as to carry out the manned space-related scientific experiments, verify the function and performance of various systems, further improve the safety and reliability, accumulate the experience in prolonged stay in space (working and living), and lay the foundation for the sustainable development of the manned space engineering.
Aboard Shenzhou-6 were the taikonauts Fei Junlong and Nie Haisheng.
The launch took place at 0100:03.583UTC. After separation from the second stage, Shenzhou-6 entered an elliptical orbit with inclination of 42.4 degrees, with a perigee of 200km and apogee of 346.8 km. In orbit the spaceship set up an in-orbit operating mode and unfolded the solar cell arrays on the propulsion module to point the sun.
When the flight began its fifth orbit, the spaceship implemented an orbital transfer to the 343 km circular orbit.
In the course of the task, the ground tracking and control center evaluated the living and working conditions of the taikonauts on the basis of the physiological parameters obtained through remote sensing, the information was transmitted back to the ground via audio communication.
In the course of flight, the two taikonauts monitored the implementation of important commands and the operating conditions of spaceship, reported the relevant situations to the ground, re-sent the relevant commands, carried out the in-orbit anti-interference test, space-ground communication test and the operation of camera and maritime satellites, and implemented a series of key control tests.
At 2033UTC on October 17, 2005, after flying around the Earth for 76 orbits, the re-entry module landed safely at the primary landing site, and the taikonauts Fei Junlong and Nie Haisheng successfully completed the manned flight task. The orbital module remained in the orbit for about half a year, carrying out space-related scientific experiments and application tests.
The next logical step in manned spaceflight development was the extravehicular activity. This important milestone took place during the Shenzhou-7 mission launched on September 25, 2008.
The main purpose of this flight was to implement the first extravehicular activity by Chinese taikonaut, master the technologies relating to extravehicular activity, and carry out the space-related scientific tests – such as satellite flight and satellite data relay.
The launch took place at 1310:04.988UTC and after riding the Shenzhou-7 and flying in space for 68 hours and 27 minutes, the taikonauts Zhai Zhigang, Liu Boming and Jing Haipeng successfully complete all the flight tasks.
During the flight, Zhai Zhigang smoothly completed the extravehicular activity. This task was another great feat for China in its pursuit of science and technology and was quick to indicate that China had become the third country in the world which independently masters the key technologies relating to extravehicular activity.
Compared with the Shenzhou-5 and Shenzhou-6 manned spaceflights, the Shenzhou-7 manned flight made important breakthroughs in a series of key technologies, including the design technology for an integrated airlock and living module, and the design technology for extravehicular activity procedures.
At 0834UTC on September 27 when the flight was in its 29th orbit, the ground control center sent the extravehicular activity command, and Zhai Zhigang – wearing the Feitian extravehicular space suit made in China, and taikonaut Liu Boming wearing a Orlan extravehicular space suit imported from Russia – implemented the EVA.
Taikonaut Zhai Zhigang opened the door of the module, and with the assistance from Liu Boming and Jing Haipeng, smoothly stepped out the module. With a camera mounted on the external surface of the module, he waved his hand, saying hello to the people of China and the people of the world. Thereafter, Zhai Zhigang showed the national flag of China.
After taking back the sample equipment mounted on the external surface of the module, he safely returned into the re-entry module. At about 1100UTC, the door of the re-entry module was closed, and the extravehicular activity was completed successfully.
At 1124 on September 27, when the flight was in its 31st orbit, the BX-1 Banfei Xiaoweixing-1 satellite carried by the spaceship was released successfully. After being released, and within a distance of 1 km from the spaceship, it took pictures and video of the spaceship.
At 0938UTC on September 28, the Shenzhou-7 spaceship safely landed at the main landing site in Inner Mongolia. The three taikonauts were classed as being in a good condition, and the Shenzhou-7 mission was successfully completed.
At 0300 UTC on October 30, 2009, the BX-1 Banfei Xiaoweixing-1 satellite – after normally working in the orbit for 400 days and flying around the Earth for 6,350 orbits – re-entered the atmosphere.
(Images via: ChinaNews.cn, BBC, CCTV, Xinhua, various Chinese media – all linked on the live thread, and Simon Zajc).