China launched an uncrewed Shenzhou 22 spacecraft to serve as an emergency lifeboat for three astronauts aboard the Tiangong space station after a docked return craft was found to have a cracked window likely caused by space debris. "A Long March 2F rocket fired its engines and lifted off with the Shenzhou 22 spacecraft, carrying cargo instead of a crew, at 11:11 pm EST Monday (04:11 UTC Tuesday)," reports Ars Technica. "The spacecraft docked with the Tiangong station nearly 250 miles (400 kilometers) above the Earth about three-and-a-half hours later." From the report: Chinese engineers worked fast to move up the launch of the Shenzhou 22, originally set to fly next year. On November 4, astronauts discovered one of the two crew ferry ships docked to the Tiangong station had a damaged window, likely from an impact with a small fragment of space junk. [...] Now, 20 days after the saga began, the Tiangong outpost again has a lifeboat for its long-term residents. Astronauts Zhang Lu, Fu Wei, and Zhang Hongzhang will return to Earth on the Shenzhou 22 spacecraft next year, soon after the arrival of their three replacements.
The Tiangong astronauts will head outside the station on a spacewalk to inspect the damaged window on Shenzhou 20. Eventually, Shenzhou 20 will depart Tiangong and reenter the atmosphere with cargo. Assuming a smooth landing, Chinese engineers will have an opportunity to get a closer look at the damage on the ground to inform the design of future spacecraft. A preliminary assessment of the window indicates the crack is in the outermost layer of heat-insulating glass in Shenzhou 20's porthole window, according to Chinese state media. Engineers on the ground conducted simulations and wind tunnel ablation tests to determine whether the window might fail during reentry. "The results showed that the cracks would still propagate further," reported CCTV, China's government-run television network. "We held review meeting, and everyone agreed that ensuring the safe return of the astronauts was too risky with the glass damaged," Zhou said.
While this crew is just one month into their planned six-month expedition, an emergency could force them to leave the station and return home at any time. Although remote, another collision with space junk, a major systems failure, or a medical emergency involving one of the astronauts could trigger an evacuation. That's why Chinese officials wanted to quickly launch Shenzhou 22 to give the crew a ticket home.The International Space Station follows the same policy, with SpaceX's Dragon spacecraft and Russian Soyuz ships serving as lifeboats until their crews' scheduled return to Earth.
The Tiangong astronauts will head outside the station on a spacewalk to inspect the damaged window on Shenzhou 20. Eventually, Shenzhou 20 will depart Tiangong and reenter the atmosphere with cargo. Assuming a smooth landing, Chinese engineers will have an opportunity to get a closer look at the damage on the ground to inform the design of future spacecraft. A preliminary assessment of the window indicates the crack is in the outermost layer of heat-insulating glass in Shenzhou 20's porthole window, according to Chinese state media. Engineers on the ground conducted simulations and wind tunnel ablation tests to determine whether the window might fail during reentry. "The results showed that the cracks would still propagate further," reported CCTV, China's government-run television network. "We held review meeting, and everyone agreed that ensuring the safe return of the astronauts was too risky with the glass damaged," Zhou said.
While this crew is just one month into their planned six-month expedition, an emergency could force them to leave the station and return home at any time. Although remote, another collision with space junk, a major systems failure, or a medical emergency involving one of the astronauts could trigger an evacuation. That's why Chinese officials wanted to quickly launch Shenzhou 22 to give the crew a ticket home.The International Space Station follows the same policy, with SpaceX's Dragon spacecraft and Russian Soyuz ships serving as lifeboats until their crews' scheduled return to Earth.
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