The future of space exploration belongs to robots and billionaires

The writer is the British Astronomer Royal, and author with astronomer Donald Goldsmith of ‘The End of Astronauts: Why Robots Are the Future of Exploration’

Nasa’s release of the stunning images obtained by the James Webb Space Telescope, the far more capable successor to the Hubble Space Telescope, marks a new era of spaceborne astronomical observation. This marvellous instrument will reveal fresh information about a host of topics ranging from the planets that orbit other stars to the birth of galaxies and the earliest years of the universe itself, opening our metaphorical eyes to the cosmos as never before possible.

The JWST’s location also exemplifies why robotic explorers are now superior to humans in space. With its decision to rely on the astronaut-orientated Space Shuttle for placing the Hubble into its orbit, Nasa condemned that telescope to remain 340 miles above the Earth’s surface. At that modest altitude, the telescope suffers significantly from the light reflected from the Earth’s surface, much as if astronomers had built modern ground-based telescopes in Greenwich rather than in Hawaii or Chile.

In contrast, the JWST now orbits the Earth and the Sun at the point called “L2,” almost a million miles away. This special location provides orbital stability along with the darkness and cold temperatures of space.

But wasn’t it true that astronauts made five trips to the Hubble to repair and upgrade its mirror and its instruments? Indeed, these missions, which occurred between 1993 to 2009, not only installed corrective lenses but also upgraded the mirrors, replaced its gyroscopes and extended the telescope’s lifetime far beyond what Nasa had dared hope for. They represent astronauts’ greatest contribution by far to exploring the cosmos.

Nevertheless, Nasa never considered a design for the JWST that would allow astronauts to repair their $10bn masterwork. A huge difference exists between launching humans into near-Earth orbit and sending them far beyond the moon. The JWST has been built to operate robotically, responding to commands sent from Earth by its human overlords.

Similar considerations apply in spades to a journey to Mars, a journey more than 100 times longer than to the JWST that takes about seven months. Humans have now sent almost 50 robotic spacecraft toward the red planet, each of which spent many months without requiring any water, food or oxygen. Some of these missions succeeded; others failed, leaving disappointment but no catastrophe comparable to the loss of astronauts.

Today, Nasa’s Perseverance rover and its accompanying helicopter have begun a detailed examination of the delta of a former Martian river, a prime spot to look for signs of ancient life. Unlike the earlier Spirit and Curiosity rovers, which had to be guided from Earth around every rock, Perseverance can manage terrain on its own. Future rovers will have even greater abilities. Thanks to human talent, our robots grow steadily more competent, while our bodies do not. So there’s a diminishing practical need for astronauts — either for exploration or for assembling structures in space.

Nonetheless, humans respond most deeply to other humans — a fact that causes many to hope that some of us will experience another world ‘for real’ rather than vicariously. But sending astronauts, providing them with the means of survival in the hostile environments of Mars and — above all, returning them safely to Earth — would cost hundreds of billions of dollars. The cost is so vast because taxpayers require Nasa to be highly safety conscious when the lives of publicly funded civilians are at stake.

Such ventures, which are indeed inspirational, should be left to billionaires and private sponsors, who can undertake cut-price projects that launch thrill-seeking adventurers who are willing to accept high risk — even one-way tickets.

It is however a delusion to believe that a hostile planet can somehow be “terraformed” to provide an earthlike environment. There is no ‘planet B’ for ordinary risk-averse people. (And this prospect shouldn’t provide an excuse to avoid repairing the negative effects of our “terraforming” Earth)

For at least the next 20 years, publicly funded efforts should continue to refine our robotic capabilities, send those emissaries to explore the solar system and use them to fabricate large structures in space such as solar energy collectors. Human space flight — at least beyond low-earth orbit — should be left to the billionaires.