Tianwen-3 (Chinese: 天问三号) is a planned Mars sample-return mission by China which would send two spacecraft (an orbiter/Earth-returner and a lander/ascent-vehicle) via two separate launches to Mars. Together, the two spacecraft will seek to obtain samples of Martian rocks and soil and then return the cached samples to Earth.^[2]

Overview

In summer 2022 during a deep space exploration technology forum held at Nanjing University, Sun Zezhou, chief designer of the Tianwen-1 mission, detailed plans for the mission based on a two-launch architecture. The mission constitutes part of the Tianwen series of space missions.^[2][3]

The current mission architecture envisions two launches during 2028 by the Long March 5 carrier rocket. One launch occurring in November 2028 will send an orbiter/return-vehicle; this spacecraft is anticipated to enter Martian orbit in August or September 2029. A second launch in either May or December 2028 will send a lander/ascent-vehicle to Mars with potential landing dates occurring in August 2030 or July 2029 respectively.

Once the lander arrives on the Martian surface it will collect surface samples, possibly via a drill on the lander and an autonomous mobile robot with multiple legs.^[3] In October 2030, after several months on the Martian surface and after storing the samples collected by the lander and mobile robot, the ascent vehicle will launch from atop the lander and rendezvous with the waiting orbiter. The ascent vehicle will transfer the collected samples to the orbiter/return-vehicle, which will depart for Earth, also in October 2030. The samples are anticipated to arrive on Earth via an atmospheric reentry vehicle in July 2031.^[1]