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.[1] The mission is scheduled to launch in 2028.[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.[1][3]
The current mission architecture envisions two launches around 2028[4][5] by the Long March 5 carrier rocket. One launch will send an orbiter/return-vehicle. A second launch will send a lander/ascent-vehicle.
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] 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. The samples will be returned to Earth via an atmospheric reentry vehicle.[6]
The main goal of the mission is search for life signatures. In 2024, scientists identified 51 potential landing sites.[7]
Missions are ordered by launch date. Sign † indicates failure en route or before intended mission data returned. ‡ indicates use of the planet as a gravity assist en route to another destination.