Long article, see link for all of it...
China successfully launches final part of its three-module space station, to complete T-shape structure assembly
By
Published: Oct 31, 2022 03:38 PM
Following the successful launch, Mengtian will carry out a fast and automated rendezvous and docking with the Tianhe space station core module at the latter's forward docking port, per the CMSA.
The new lab module will then be transpositioned from the forward docking port on Tianhe to the port docking ring on the side, joining the two earlier modules - Tianhe core module and Wentian lab module, to complete the T-shape China Space Station basic structure.
After completing the building of the China Space Station, six taikonauts of two Shenzhou manned spaceflight crew will carry out the first-ever direct handover in orbit.
The powerful Long March-5B carrier rocket has successfully launched all three modules, each weighing over 22 tons at launch, of the China Space Station to date, proving its strength and reliability, the carrier developer the China Academy of Launch Vehicle Technology said in a statement.
The Long March 5B is a one and half stage carrier rocket with four 3.35-meter-diameter liquid propellant boosters, and has a thrust of 1,078 tons by take-off. It is capable of sending payload of 25 tons to the near-Earth orbit.
Huang Bing, the chief designer of the Long March 5 rocket series, told the Global Times that to meet the mission demands of the space station module launch missions, the Long March-5B rocket has made multiple key technology breakthroughs including the separation of the country's largest nose cone at 20.5 meters in length.
The Global Times learned from the Shanghai Academy of Spacecraft Technology (SAST) the developer of the Mengtian module that 17.88-meter-long, 4.2-meter-diameter mega space lab weighs around 23.3 tons by launch, which is the heaviest payload China has ever launched to date.
Mengtian module is designed to be a working zone for astronauts and therefore it does not have life support systems like Tianhe and Wentian, nor the dormitory and restrooms. But Mengtian does have installed physical training facility onboard that is similar to the rowing machine on Earth, the SAST introduced.
As the "workshop" for the China Space Station, Mengtian has the most powerful payload supporting capabilities, as it carries 13 standard payload cabinets, hosting experiments mainly in the fields of microgravity scientific studies as well as frontier scientific projects covering fluid physics, combustion and materials science and space technologies.
The Mengtian will carry the world's first space-based set of cold atomic clocks which will include a hydrogen clock, a rubidium clock and an optical clock.
"If successful, the cold atomic clocks will form the most precise time and frequency system in space, which should not lose one second in hundreds of millions of years," said Zhang Wei, director of the Utilization Development Center of Technology and Engineering Center for Space Utilization under the Chinese Academy of Sciences.
The world's first cold atomic clock that operates in space was made by Chinese scientists. It was launched with the Tiangong-2 space lab in 2016, and has a margin of error of less than one second in 30 million years.
Now, through ground-based experiments, Chinese scientists have developed cold atomic clocks that are far more accurate than the Tiangong-2 version, according to Zhang.
The development of space cold atomic clock technology will contribute to higher-precision satellite positioning and navigation, and support fundamental physics research such as dark matter probes and gravitational wave detection, scientists explained.
Mengtian is made up with four cabins including the working cabin at the forefront connecting to the Tianhe core module in which astronauts can work and do their physical exercises, and interior scientific experiment cabinets are installed.
Moving further from the working cabin, there are payload cabin on the outside and airlock cabin on the inside. That is to say, there is a hidden cargo airlock cabin that will be used for cargo passage. And at the further end of the Mengtian, it is the module's resource cabin where the Sun-positioning device and flexible solar panels are installed.
To facilitate the supporting function for experiments outside the cabin, Mengtian has prepared as many as 37 payload installation spots on the exterior, providing services such as engineering, electronic as well as information technology support for those experiment to be carried out outside the cabin.
Mission insiders explained that if the airlock cabin on the Wentian lab module is the international airport that would be mainly used to support entry and exit of taikonauts, the airlock cabin on the Mengtian module will be the "international cargo port" for the robotic transfer of cargo and scientific payload.
Previously, to carry out experiment on the exterior of the space station cabin, it required taikonauts to conduct extravehicular activities (EVA), but efficiency was limited to the times that EVAs could be arranged and other factors such as the number of payloads and their size.
Now with the new cargo airlock on Mengtian and its unique payload transfer mechanics, cargo including experiment payload could smoothly enter and exit the cabinet automatically.
Such robotic cargo and payload transfer capability reaches 400 kilograms and the size of the cargo envelope for a single shipment reaches 1.15 meters x 1.2 meters x 0.9 meters, greatly increasing the efficiency and reducing the pressure of astronauts, enabling them to invest more time and energy to focus on interior scientific experimental activities.
Also to meet the demand for entry and exit of larger and heavier cargo, Mengtian has installed the country's first square shape port gate, whose width reaches 1.2 meters.
To maximize the use of the space workshop, Mengtian has also been designed to be able to release smaller cube satellites in orbit. Astronauts only needs to put those 100-kilogram-level micro spacecraft or cube satellites in different sizes into the releaser inside the Mengtian, and then the releaser could "throw" them like a pebble bow, realizing the low-cost entrance to space for these micro spacecraft and cube satellites in orbit.
Just like Wentian lab module, Mengtian has also taken the power solution into consideration to prepare for future more demanding in-orbit experiments. Mengtian is also equipped with giant flexible solar panels, each of which can extend some 138 square meters.
After the completion of the T-shape China Space Station, two pairs of such solar panels on Wentian and Mengtian modules could together generate nearly 1,000 Kilowatt hours of electricity per day, equivalent to the half-year consumption of a household, and according to the SAST, it will mean that the space station will be free of worries of using electricity.