THE US National Research Council (NRC) warned space agency Nasa today that its mission to send humans to Mars would fail unless it revamped its strategy.

A congressionally commissioned NRC report said that Washington should use “stepping stones” to achieve manned flight to Mars.

This could involve building more international co-operation with space-capable countries like China, it noted.

“To continue on the present course … is to invite failure, disillusionment and the loss of the long-standing international perception that human spaceflight is something the US does best,” the NRC said.

To date the world’s space agencies have only managed to send unmanned robotic rovers to Mars, the latest being Nasa’s $2.5 billion Curiosity rover, though Indian satellite Mom and Nasa satellite Maven are en route to the planet.

But advancing human exploration further into space will require decades of work, hundreds of billions of dollars of funding and “significant risk to human life,” according to the NRC.

That, the report said, made it impossible for the US to go to Mars within its current budget.

Instead, it called for increased co-operation with other nations, including China.

Current federal law bars Nasa from participating in bilateral programmes with China, which the council warned “reduces substantially the potential international capability that might be pooled to reach Mars.

“Given the rapid development of China’s capabilities in space, it is in the best interests of the US to be open to future international partnerships,” the report said.

Nasa welcomed the findings, saying it was consistent with the Mars plan approved by Congress.