What’s China’s plan?
China has said its intention to conduct a Mars pattern return mission for years, however solely now, after its house program’s current successes, are extra strong particulars of the mission — referred to as Tianwen-3 — rising.
Earlier this summer season, Solar Zezhou, the chief designer of China’s first Mars mission, gave a large replace on Tianwen-3, which included unveiling new mission profiles, particulars concerning the spacecraft and their configurations, and among the applied sciences concerned.
The mission requires a pair of launches in 2028 that will return a pattern to Earth in July 2031. If profitable, Tianwen-3 could be the first-ever robotic supply of Mars samples to Earth. Whereas NASA and the European Area Company have proposed their very own joint Mars pattern return mission, it wouldn’t return to Earth till two years after Tianwen-3.
Tianwen-3 would use two spacecraft: one for touchdown and accumulating, and one other for orbiting and pattern return. The touchdown section would encompass a lander that will contact down on Mars to gather rock samples. It will additionally carry an ascent car to ship the collected materials again into house.
As soon as in Mars orbit, the ascent car would dock with the orbiter, which might be launched individually from the touchdown section. The orbiter is tasked with escorting the samples again to Earth and would carry a return capsule designed for delivering the Martian materials safely by means of a high-velocity, high-temperature reentry into Earth’s environment.
There are at the moment two completely different mission profiles into consideration. In each configurations, two Lengthy March 5 rockets — the identical kind of launch car that carried Tianwen-1 and Chang’e-5 — would every launch one of many spacecraft. The orbiter would blast off from Wenchang on the island province of Hainan in November 2028.
The principle distinction between the 2 mission profiles is whether or not the lander launches earlier than or after the orbiter. One profile requires a December 2028 launch of the lander, which might arrive on Mars in July 2029 and spend about 6 months accumulating samples. Alternatively, the lander might launch earlier — exterior of the normal low-energy Mars launch window — in Might 2028, and land solely in August 2030. In each profiles, the orbiter would arrive forward of the lander, in August or September 2029.
A later touchdown might provide higher photo voltaic power circumstances, avoiding winter within the Northern Hemisphere, however would enable much less time — round three months — on the floor earlier than the liftoff of an ascent car in October 2030. Each mission profiles would see the orbiter depart from Mars and head residence in October 2030, with landing of the samples on Earth scheduled for July 2031.
Earlier mission profile displays steered the usage of a Lengthy March 9, an excellent heavy-lift rocket at the moment below growth that may very well be able to fly round 2028. One other proposal was to make use of a Lengthy March 5 and a Lengthy March 3B. The swap to a pair of bigger Lengthy March 5 suggests there could have been adjustments to the lander design.
Whereas China has not mentioned its plans for touchdown websites, the sooner Tianwen-1 mission may very well be instructive since China already proved the know-how wanted to land in that area. The 2021 Zhurong touchdown came about within the flat, low elevation area Utopia Planitia within the Northern Hemisphere, which implies the spacecraft had extra time within the environment to sluggish its descent. Touchdown at greater altitudes on Mars — as some NASA spacecraft have executed — would require additional refinements of entry, descent, and touchdown (EDL) know-how and improve the complexity of the mission.
China constructed safe labs on Earth for dealing with its lunar samples, however it’s unclear at this level the way it will handle the wants and issues of coping with recent samples from Mars. It’s additionally unknown simply how a lot materials China intends to convey residence with Tianwen-3.
