The world’s space agencies should scrap plans to send astronauts to the moon and Mars and leave them to explorers and billionaires who can privately fund and risk such adventures, the astronomer royal says.
Lord Martin Rees said technical improvements and more sophisticated artificial intelligence meant robotic missions were becoming ever more capable of exploration, and even construction, in space, making it unnecessary for space agencies to front far-flung human missions.
“We should not have publicly funded programmes to send people to the moon, still less to Mars,” said Rees. “It’s hugely risky, hugely expensive, and there’s no practical or scientific benefit to sending humans. It’s a pretty bad bargain for the taxpayer.”
His comments prompted a robust defence from some experts, who stressed that government-backed spacefaring is a way to project soft power and provided huge inspiration, adding that the private sector could turn space into the “wild west”.
But Rees argues we should encourage and cheer on explorers and billionaire entrepreneurs who want to leave Earth in search of adventure in the spirit of Shackleton and Scott – both of whom died on Antarctic expeditions. The SpaceX founder, Elon Musk, has long enthused about moving to Mars, noting “there’s a good chance of death”.
While human genetic modification should be heavily regulated on Earth, Rees said, Mars settlers would be free to enhance their children to cope with life on the red planet. Doing so could drive the divergence of the species, he added, raising the unsettling prospect of Silicon Valley entrepreneurs being the seed stock for a bunch of puny post-humans, given the weak Martian gravity.
“They will have every incentive to try to redesign themselves and these changes are going to be rapid compared with Darwinian evolution,” Rees said. “If something evolves that’s rather different from present day human beings, it’s likely to evolve from them, not us.”
Astronauts last set foot on the moon half a century ago. Since then, humans have not ventured further than a few hundred miles into space, mostly to the International Space Station. Space agencies, including from the US, Europe, China and Russia, are now on course to return to the moon. Mars is next in line.
The cost is considerable because humans are fragile. The US president, Joe Biden, has requested $26bn (£20.6bn) for Nasa in 2023, with $7.5bn earmarked for the Artemis programme which aims to put the first woman and the first person of colour on the moon as early as 2025.
“I think many people support the idea of science in space and assume humans are an essential part of that. In a way they are, because an astronaut knows more geology than a present-day robot,” Rees said. “But the kinds of robots we will send in 20 years may be able to decide where to dig on Mars as well as any actual geologist could.”
Closer to Earth, Rees fears the phrase “space tourism” underplays the danger in the activity. He wants it rebranded as high-risk adventure so inevitable tragedies do not become national traumas, as happened when Nasa lost space shuttles in 1986 and 2003.
Even brief trips to the edge of space, such as those planned by Virgin Galactic, are risky. “There are going to be crashes even on these suborbital flights, and they’ll be less traumatic and seem less of a disaster if they are viewed in the way of someone falling off Everest, rather than a civilian airliner crash,” he said.
The astronomer, who argues the case in a new book, The End of Astronauts, believes private spacefarers will inspire people as much as space agency astronauts. But others are sceptical.
Prof David Southwood, a former chair of the UK Space Agency and senior research investigator at Imperial College, said: “If you’ve ever been in a room with Tim Peake and a couple of hundred schoolchildren, there’s a buzz and enthusiasm because he’s done something very few people have done, out on the final frontier. They think ‘he’s like me’. You don’t have to be a billionaire.”
Didier Schmitt, the head of the strategy and coordination group for robotic and human exploration at the European Space Agency, said the trend for human spaceflight being used as soft power and power projection would continue.
“The robotic versus human spaceflight rhetoric is an old debate that has definitely been superseded by the US and Chinese new race for the moon and Mars,” he said.
Leaving human exploration to the private sector risked “a wild west approach in space”, he added, stressing it was important to balance private exploitation with public exploration in space.
“It is a duty for governments, and not the free market, to enthuse the younger generation,” he added. “Taking into account the 22,500 candidates for the next European Space Agency astronaut corps is a clear message to politicians.”