If you ask my four-year-old son, he’ll tell you there’s nothing cooler than a space rocket. Be it a plastic Thunderbird, a die-cast Shuttle or a handmade wooden model, there’s something about pretending to blast off into space that sets his imagination alight.
His fascination came to mind last week when someone asked whether all the money being funnelled into missions to Mars and Saturn mightn’t be better spent elsewhere - such as Earth, for example.
Questioning the cost of space science is perfectly reasonable. After all, the final bill for the international Cassini-Huygens mission to explore Saturn and Titan will top $3bn, and there’s much more to follow. Taking President George Bush’s lead, NASA has embraced a new “Vision for Space Exploration”, and is planning to send another spaceship to Mars and establish long-term bases on the moon by 2020.
Considering that we’re burning through fossil fuel like there’s no tomorrow while the environment apparently falls down around our ears, it is only rational to ask whether the money wouldn’t be better spent on Earth rather than outer space.
In fact, those very questions were posed in early February at London’s Dana Centre, a forum for public discussion of science set up by the British Association for the Advancement of Science along with the Science Museum. A panel of scientists and others tussled with questions including: “As we launch more missions into space, is it part of our human destiny to colonise other worlds?” and “Before we step on to other planets, should we not consider the health of our own?”
During the discussions, the speakers knocked the second of those questions on the head rather swiftly. It is perhaps just a little specious to suggest that we have to make a choice between spending our money on Earth or in space, they said - there’s no reason why we can’t do both.
What’s more, the cost of exploring space isn’t actually that great compared, say, with military budgets. (As a spokesman for the European Space Agency tells me, its entire budget costs the EU the equivalent of a burger and a Coke per capita each year.)
A few days after the Dana session, I spoke to one of the panellists, Ian Crawford, a planetary scientist from Birkbeck College London. He pointed out that the economic costs of sending rockets, satellites, probes and people into space are further outweighed by several hard-headed benefits.
First, the enormous challenges of space exploration stimulate the development of new and innovative technologies - such as miniaturised electronics and computers - that soon develop other uses. (Incidentally, it is hard to have a conversation on this subject without someone mentioning how DuPont’s Teflon was a spin-off from space research - it was nothing of the sort. It was a side-product of research on refrigerators.) Secondly, big space programmes trigger intellectual advances, train workforces and spur on innovation - all of which have ripple-down effects on the wider world.
There are also enormous benefits to us in better understanding the universe. To take just one very nearby example, the geological history of the moon can help inform our understanding of the Earth’s history.
”I think it’s not sufficiently appreciated that the moon has been orbiting the earth for the past 4,500 million years,” Crawford says. This means that the moon preserves a geological record of the first billion years of our solar system’s history, which the Earth has lost. “There’s a tremendous archive of the early solar system preserved there and it’s only three days away.”
Another example: over the next few years, scientists will launch a collection of large instruments that will be able to identify Earth-sized planets around other suns and analyse the light they emit, to determine the composition of the atmosphere and see whether there is anything that suggests biology has evolved on the planet below.
By observing hundreds of the closest stars, they will be able to form a statistical estimate of the presence of life elsewhere. If, say, we looked at the 100 stars nearest to us, found that each was orbited by an Earth-like planet, of which five had oxygen in the atmosphere, then you could say that probably at least 5 per cent of terrestrial planets have life that has evolved to the level of photosynthesis.
”That would be real scientific knowledge; that would be a real gain in our understanding of the prevalence of life in the universe,” says Crawford.
Some would argue that some of the benefits of technology and education and scientific knowledge could be gathered in other ways. But, in my view, my son’s love of rockets is a pointer to perhaps the most compelling of all reasons to fund space exploration - it is an expression of our yearning for knowledge and it can inspire us, regardless of whether it brings more “down-to-earth” benefits.
When he was preparing for the Dana talk, Crawford looked at a children’s encyclopedia that he had been given aged nine or 10. “I was imagining what it would be like if you ripped out all the things sometimes claimed to have no practical applications - the Apollo space programme, Concorde, medieval cathedrals - what would you be left with? A pale shadow that would inspire no one.” You’ll get no argument from the youngest member of my family.
