Debris-hit spacecraft returns after 270 days in orbit

The return capsule of the Shenzhou XX spacecraft, carrying no astronauts, landed safely on Earth on Monday, concluding an extended orbital mission that was prompted by an unprecedented incident.

The China Manned Space Agency said the vessel undocked from the Tiangong space station at 12:23 am and began its unmanned return journey, ending a 270-day flight in orbit.

The capsule touched down at 9:34 am at the Dongfeng landing site in North China's Inner Mongolia autonomous region, the agency said, adding that a preliminary on-site inspection by ground recovery personnel confirmed that its exterior was intact and the payloads inside were in good condition.

On April 24, a Long March 2F rocket blasted off from the Jiuquan Satellite Launch Center in northwestern China carrying three astronauts aboard the Shenzhou XX spacecraft.

Shenzhou XX mission commander Senior Colonel Chen Dong and crew members Colonel Chen Zhongrui and Colonel Wang Jie were scheduled to return to Earth on Nov 5, after completing all assigned tasks and handing over control of the space station to the Shenzhou XXI crew, who arrived on Nov 1. However, on Nov 4, the astronauts spotted cracks on their return capsule's viewport window.

After receiving the report of the damage, suspected to have been caused by tiny pieces of space debris, the mission command promptly organized simulation analysis and experimental verification, adjusting the mission plan and activating emergency procedures, according to the space agency.

As a return capsule is expected to endure friction temperatures exceeding 1,000 C during atmospheric reentry, the Shenzhou XX was deemed unfit for crewed descent and the return of the astronauts was postponed.

On Nov 14, the Shenzhou XX crew safely landed on Earth aboard the Shenzhou XXI spacecraft, completing an extended 204-day mission.

Eleven days later, the emergency launch of the unmanned Shenzhou XXII spacecraft was successfully carried out, marking the first such operation in the history of China's manned space program, the agency said. This spaceship will serve as the return vessel for the three Shenzhou XXI astronauts when their mission ends in April.

Meanwhile, to facilitate the descent of the Shenzhou XX spacecraft, the Shenzhou XXI team carried out extravehicular activities on Dec 9, capturing close-up images of the return capsule's damaged window using a high-definition camera.

They installed a specially designed device on the damaged window, effectively enhancing the capsule's heat resistance and airtightness, the agency said.

It added that the Shenzhou XXIII spacecraft, which will be used for a rolling backup mission, has already arrived at the Jiuquan spaceport, and the Long March 2F Y23 rocket that will carry it to orbit will be transported to the launch center in due course.

zhaolei@chinadaily.com.cn