Big news for China’s space program this week, from the CSS and from the Martian orbit. First, the Shenzhou 13 crew, composed of taikonauts Zhai Zhigang, Wang Yaping and Ye Guangfu, performed its first EVA on November 7
- with the two former leaving the capsule. This 3rd EVA being performed on the CSS has some historical significance. Indeed, Zhai Zhigang was the first Chinese to ever perform a spacewalk, back in 2008 as the commander of the Shenzhou-7 crew. As he stepped out of the cabin, he pronounced the exact same words as in 2008: “我已出舱，感觉良好“
(I’ve exited the station, I feel fine). Secondly, Wang Yaping was the first Chinese woman ever to perform a spacewalk. The main objective of this EVA, which lasted 6.5 hours, was to install the systems to enable two robotic arms of the CSS to work together - namely an adapter (转接件)
and a suspension system (悬挂装置)
. While the first robotic arm is already installed, a second, shorter robotic arm will be sent with the Wentian experimental module, which will dock with the Tianhe-1 next year.
The crew will be on-board for another 5 months, representing a total of 6 months, which is the routine length also for astronauts on the ISS. Among their remaining tasks will be 1) to use the robotic arm to move TZ-2 from the front docking port of the multidocking node to one of the side docking ports, 2) controlling the robotic arm remotely, 3) 1-2 more EVAs, 4) space sciences experiments, 5) the apparently long awaited second live science classes taught by Wang Yaping from the space station.
Secondly, on November 8, China’s Tianwen-1 orbiter performed braking maneuver and entered the final remote sensing phase
. China’s Tianwen-1 orbiter has been serving as a relay satellite for the Zhurong rover ever since the Zhurong lander and rover detached from the orbiter to perform a landing on Mars on May 15. Last week, the orbiter completed some orbital maneuvers, firing up its 4x120N during 260 seconds
to change its orbit to a new one that would be much more favorable to space sciences
Such an orbit is one that tends to minimise the difference between the apoapsis
(point in an orbit where a spacecraft is the farthest
to the planet) and the periapsis
(point in an orbit where a spacecraft is the closest
to the planet) - also called apoareion and periareion since the orbited planet is Mars (Ares in Greek). As a result, while the periapsis used to always be over the same area around Zhurong, to enable maximum resolution and best communication with the rover, it will now be drifting between the North and South poles with every orbit, thereby being able to image the entire Martian surface over a period of ~200 days (until ~06/2022)
and enabling more scientific research to be performed. According to an interview of the deputy chief designer of the Tianwen-1 orbiter Zhu Xinbo (8th Academy)
, as Tianwen-1 enters the remote sensing orbit, it will (or probably already has) deployed the 4 antennas that compose its Mars Subsurface Radar instrument (次表层雷达), one of the 7 instruments of the orbiter. Check out our weekly episode
for more technical details!