China invites the world on its mission to Mars while Nasa reels from Trump cuts

Short deadline for science project submissions suggests Tianwen-3 could be on track to win race to bring samples back to Earth

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International bidders for a place on board China’s Tianwen-3 mission to Mars have until June to submit letters of intent, with final decisions expected in October. Image: Shutterstock

Published: 2:00pm, 13 Mar 2025Updated: 3:59pm, 13 Mar 2025

Applications are open for international science projects to join China’s Tianwen-3 mission to Mars, indicating that it is on track to launch in 2028 and increasingly likely to be first in the race to retrieve samples from the red planet.

As the official invitation was issued by the China National Space Administration (CNSA) on Wednesday, Nasa was facing new challenges – including the loss of its chief scientist – in the first round of cuts ordered by President Donald Trump and in the midst of uncertainties about its own Mars mission.

According to CNSA, the Tianwen-3 selection process to determine the successful projects will follow an accelerated timeline, with letters of intent due by June and final decisions expected in October.

Each chosen project will be offered a free ride for up to 20kg (44lb) of instruments – if they can be ready by 2027. “This opportunity is open to the global community,” said the agency in a statement on its website.

Eligible projects will align with Tianwen-3’s primary scientific objectives – such as the search for signs of past life on the planet – or will need to provide complementary or extended value to the mission, while showing “strong innovation in science and engineering”, it said.

Planetary scientist Qian Yuqi, from the University of Hong Kong, said the announcement confirmed that Tianwen-3 was on schedule. He also noted the contrast with the dramatic shake-up at Nasa, where more cuts are expected.