China’s Mars sample return mission ‘progressing smoothly’ while Nasa struggles behind schedule

• NPC deputy and Tianwen-1 spacecraft chief designer Sun Zezhou says key technologies needed for Tianwen-3 mission are ‘in place’
•  
• The cost of the US Mars Sample Return programme has risen from an initial US$4 billion and will probably exceed US$10 billion
•  

“So far, no country has implemented a sample return from Mars yet,” Sun told state broadcaster CCTV on Wednesday, adding that China must overcome two major challenges for Tianwen-3 to be successful.

“One is to retrieve rock samples and then take off from the Martian surface. The second is an in-orbit rendezvous and transfer of the samples to the return capsule. They require our spacecraft to be highly intelligent at the system-design level,” he said.

Analysing the retrieved rocks with state-of-the-art instruments here on Earth, scientists could better answer fundamental questions such as if there was still water on Mars and whether it had hosted any form of life in the past, he said.

China is increasingly likely to become the first country to carry out a Mars sample return mission – though the US has a much longer history exploring the red planet that goes back to the 1960s.

In the past few months, Nasa’s work on the Mars Sample Return (MSR) project has slowed after budget uncertainty emerged and an independent review called the project timeline “unrealistic”.

MSR was set to gather Martian rocks, which are now being collected by Nasa’s Perseverance rover in Jezero Crater, and return them to Earth around 2031. The total cost risen from an initial US$4 billion and is likely to end up passing the US$10 billion mark.

There are also problems with the mission’s technical readiness. The probability of Nasa and its European partners getting the spacecraft ready for launch by 2028 – so it can catch the return window in 2030 – is “near zero”, according to the independent review.

In February, the Jet Propulsion Laboratory in Pasadena, California, which is Nasa’s leading MSR developer, laid off 8 per cent of its staff because of potential spending cuts from the US Congress, especially for the MSR project.

Despite delays and uncertainties, scientists still hope to see the MSR programme happen because its sampling sites are diverse and carefully selected for high scientific value.

In comparison, China’s Tianwen-3 is more likely to be limited to collecting and retrieving materials within the immediate reach of the lander.

Besides Tianwen-3 and the American MSR, India and Europe are also sending missions to the red planet soon. Their respective spacecraft – Mars Orbiter Mission 2 and ExoMars Rosalind Franklin rover – are set to launch in 2024 and 2028 but are not designed to retrieve samples.