Wentian module
The Wentian laboratory cabin module, is a major component of the Tiangong space station. It is the first of the station’s Laboratory Cabin Modules and the first module added to the Tianhe core module.
Wentian was launched on 24 July 2022 from the Wenchang Spacecraft Launch Site and docked with Tianhe later that day. The crew of Shenzhou 14 entered the module for the first time a few hours later. On 30 September 2022, the module was relocated to the starboard port by the station’s indexing robot arm to prepare for the arrival of the Mengtian.
Purpose
The Wentian laboratory module provides additional navigation avionics, propulsion and orientation control as backup functions for the Tianhe Core Module. It also provides a pressurized environment for researchers to conduct science experiments in freefall or zero gravity which could not be conducted on Earth for more than a few minutes. Experiments can also be placed on the outside of the modules, for exposure to the space environment, cosmic rays, vacuum, and solar winds.The forward docking port of Wentian is fitted with rendezvous equipment and first docked to the forward port of Tianhe. A mechanical arm called the "indexing robotic arm", and similar in function to the Lyappa arm used on the Mir space station moved the module to a starboard port of the TCM on 30 September 2022. It is different from the Lyappa as it works on a different mechanism. Mir's Lyappa arm is needed to control the pitch of the spacecraft and redocking in a different plane, but the Wentian indexing robot arm is used when docking is needed in the same plane. In addition to this arm used for docking relocation, the Chinarm on Tianhe module, could also had been used as a backup of the indexing robot arm.
In addition to this, it also carried a small long robotic arm like the Chinarm as a supplemental to that arm. It is used for manipulating extravehicular payloads and assisting EVAs. Its positioning accuracy is 5 times better than the Chinarm. Wentian in total has 22 standard adaptors to host the payloads. Wentian
Electrical power is provided by two steerable solar power arrays, which use photovoltaic cells to convert sunlight into electricity. With a wingspan of over 55 m, each array has an energy collection area of 110 m2. The energy is then stored to power the station when it passes into the Earth's shadow. Resupply ships will replenish fuel for LCM 1 for station-keeping, to counter the effects of atmospheric drag.
Aftermath
After launch, the Wentian module was inserted into a low Earth orbit with an average altitude of at an orbital inclination of 42 degrees, centered in the Earth's thermosphere. It successfully docked with the Tianhe core module nearly thirteen hours after launch.During the re-entry phase of the Long March rocket's main core stage, NASA Administrator Bill Nelson voiced criticism for allowing the stage to return to the Earth in an uncontrolled re-entry. The stage eventually made re-entry and splashed down over the Pacific Ocean on 30 July 2022, with the bulk of it burning up on re-entry and no known pieces that survived re-entry causing damage.