May 8, 2007
Do We Need to Send People into Space, or Could Robots Do It Better?
By STEVE CONNOR
Why are we asking this question now?Professor Stephen Hawking has just completed a series of "zero- gravity" dives in an aircraft designed to test weightlessness in space. Professor Hawking, one of the foremost experts on the cosmological theories of gravity and black holes, said he wants to see the Earth from space by going for a ride with Sir Richard Branson's company Virgin Galactic, which is scheduled to offer tourist trips into "space" in two years.
Hawking believes that travelling into space is the only way humans will be able to survive in the long-term. He said in a statement released before his gravity-defying flight: "Life on Earth is at the ever-increasing risk of being wiped out by a disaster such as sudden global warming, nuclear war, a genetically engineered virus or other dangers ... I think the human race has no future if it doesn't go into space."
"I don't think the human race will survive the next 1,000 years unless we spread into space," he said in 2001. "There are too many accidents that can befall life on a single planet."
How are we going to get into space?
For now, and the foreseeable future, it will remain a preserve of rich people. A number of organisations led by wealthy entrepreneurs are following Sir Richard's lead in developing a fledgling space- tourism business. Sir Richard is said to be investing [pound]100m in Virgin Galactic and has signed up 200 people at a cost of [pound]100,000 a ticket. The flight will take two and a half hours, but the period in "space" will last just a few minutes - less than four to be precise - before the passengers are returned to the space port in New Mexico where they took off.
The Benson Space Company, led by American Jim Benson, is also offering similar flights into space - actually a high-altitude trip to a point 63 miles above ground. Space officially starts at 62 miles, so at this altitude the passengers will earn their "space wings" from Nasa and the US Air Force. Like Virgin Galactic's tour, however, these flights will be suborbital trips, which means that the passengers will not get to orbit the Earth. They will merely be taken to a great height and back again to the same point on the ground.
What is the point of a suborbital space trip?
Good question. At these altitudes it is possible to see the curvature of the Earth and look down on the thin smudge of air; our life-support system.
Critics will argue that the space tours being promoted by billionaires such as Branson and Benson will merely provide rich people with a good view of the atmosphere that their carbon-hungry trip has just helped to destroy - the ultimate 4x4 experience.
Encouraging rich people to go for short, but expensive, joy rides into space appears to be led by even richer men with a boyish fascination for space travel. Alongside Branson and Benson, other entrepreneurs of the private space-tourism industry include Elon Musk, the founder of PayPal, Paul Allen, the cofounder of Microsoft, Jeff Bezos, the founder of Amazon.com, and Robert Bigelow, the American hotelier.
They argue that space tourism is about adventure and excitement, but the bottom line is that they also believe, with the right work behind it, it can be profitable.
How does space tourism compare with the real thing?
Yuri Gagarin became the first man in space on 12 April 1961 when he circled the Earth for 108 minutes in the Soviet spacecraft Vostok- 1. Since then scores of astronauts from dozens of countries have followed his lead. Most astronauts have stayed in near-Earth orbits, either servicing satellites or the International Space Station, or travelling to the higher orbit of the Hubble Space Telescope.
A few have gone beyond the orbit of the Earth, notably Nasa astronauts on the Apollo missions to the Moon. President Bush has announced a mission to return to the Moon by 2020, and many countries, such as Russia, China and the nations that make up the European Space Agency (ESA), have stated that they too want to send people to the Moon. Once on the Moon, the US intends to build a permanent lunar base and use it as a possible staging post for a manned mission to Mars by the middle of the 21st century.
All these missions are very different from the limited tours being planned by the private sector. Nevertheless, some scientists believe that the future of manned space travel could rest with risk- taking privateers, rather than risk-averse public bodies such as Nasa and ESA.
Is it not better to send robots to explore space?
Many intelligent people believe this is the case, given that a robot mission costs between 10 and 100 times less than a manned mission. Safety in space can be incredibly expensive, and to send people aloft means that three or four levels of safety precautions have to be built in to minimise risks.
Robots are a long way from being able to substitute humans. A robot geologist, for instance, might take weeks analysing a Martian landscape or a piece of lunar rock that a human specialist could evaluate in minutes. Steve Squyres, the principle scientist on the Nasa mission to explore Mars, pointed out that for all their apparent sophistication, space robots are still relatively primitive machines. "We are many decades away from robots that can match humans even in the lab. And laboratory robotics is about 20 years ahead of space robotics," he said.
So who is in favour of manned space flight?
Most of us, apparently. A recent BBC poll found that 61 per cent of the public is in favour of Britain playing a leading role in human space exploration. The proportion is even higher in America.
A recent report by scientists at the Royal Astronomical Society, in London, also came out in favour of manned space flight. "We find that profound scientific questions relating to the history of the solar system and the existence of life beyond Earth can best, perhaps only, be achieved by human exploration on the Moon or Mars, supported by appropriate automated systems," the report said.
Perhaps the argument for manned space flight is best summed up by Lord Rees of Ludlow, the Astronomer Royal Martin Rees: "My view about manned space flight is that, as a scientist and practical man, I'm against it, but as a human being I'm in favour of it."
Advances in robotics is making the case for manned space flight weaker, but there is still a need for it in terms of human adventure.
Should we send people into space?
It is the ultimate adventure to 'boldly go' where no man has gone before
Robots, despite all their apparent sophistication, will never be as adept in space as humans
Rich people with a fascination for space travel need something to spend their money on
There are more pressing problems on Earth to solve before we dream of space colonisation
Space robots, though relatively primitive machines, are cheap and dispensable, people are not
The rich must learn that space tourism is bad for the planet we all have to live on