August 02, 2012
Rumbling into the future … NASA's guidance, navigation and control systems manager, Steve Lee, points out the features on Curiosity. Photo: Reuters
The agency needs to stop sending people into space and start looking for life, writes Michael Hanlon.
Early next week, an extraordinary machine will plunge down in a sheet of flame, pirouette through the Martian skies and come to rest, Newton willing, on the floor of a rocky crater next to a mountain almost five kilometres high. The Mars Science Laboratory, aka Curiosity, is a $US2.5 billion ($2.38 billion) robotic planetary rover. This nuclear-powered craft, a tonne in weight and the size of a small car, is by far the largest, most complex and most expensive unmanned probe ever sent to the surface of an alien planet. Curiosity's brief is to spend several years poking around Gale crater, perhaps climbing Aeolis Mons, and looking for signs of past and even present life on the Red Planet.
Just about everyone agrees that Curiosity is an example of what NASA does best: robotic planetary exploration, on a tight budget, with maximum bang (in science terms) per buck. And this, I would argue, is also the only way forward for an agency that has otherwise lost its way - a pointer to a new focus that could yet herald the true dawn of the space age.
Since the days of the Pioneers, Voyagers and Mariners of the 1960s and 1970s, NASA's star performers have been the robot brainchildren of the Jet Propulsion Laboratory, its outpost in Pasadena, California. These machines have glimpsed lakes on Titan, flown through the rings of Saturn, photographed fire-fountains on Io and sniffed briny oceans on Europa - all for a total cost, over 50 years, that amounts to what the Pentagon spends in eight weeks.
To see the opposite of this pure brilliance, simply fly across the US to the Johnson Space Centre in Houston, Texas, home to the Astronaut Corps. High on expectations after the Apollo moon landings, NASA's Human Space Flight division has spent four decades pouring cash down the drain and going nowhere.
Since the Space Shuttle program was cancelled last year, America's manned program has been in chaos. Officially, a new spacecraft called Orion, revealed earlier this month, will take American astronauts out of low-Earth orbit for the first time since 1972, first to the moon, then to the asteroids and on to Mars. The first flights are scheduled for 2014, with the moon missions slated for the 2020s.
But it won't happen. There is no national leadership, no inspiration, no goal. Budgets will be cut, timetables will slip. The great thing about the moon as a destination is that you can stand on the White House lawn and point to it. But NASA will not get funding to send astronauts to asteroids - for the simple reason that most American taxpayers don't care about asteroids, even if they know what they are.
So what should NASA do? After all, the agency still has considerable funds at its disposal; more, theoretically, since the pointless space shuttles were finally grounded. I believe that it should, along with its international partners such as the European and Russian space agencies, refocus on one overriding goal: to search for life outside the Earth - scrapping more or less everything else.
After all, there can be no more pressing or fascinating question in the whole field of space exploration and astronomy. To discover that Earth's biosphere is unique, to find that even the most Earth-like planets out there are no more than sterile rocks, to discover that wherever we look, we see not even bacterial slime, would be extraordinary. If the evidence stacked up that we are indeed alone, our view of ourselves - of our place in the universe and our custodianship of our planet - would take on a whole new meaning.
And, of course, the alternative would be just as awe-inspiring. Finding microbial life on Mars with a different genetic make-up to earthly life (showing that the Martian bugs are not the result of meteoritic cross-contamination between the two planets) would suggest that life is everywhere. The biochemist Nick Lane, of University College London, one of the surprisingly few scientists in the world studying the origin of life, suggested recently that microbial life probably is everywhere, but that evolution to more complex forms such as recognisable animals and plants demands a series of biochemical flukes that may yet mean that life as we know it is vanishingly rare. This fascinating idea needs exploring.
Under its strategy, what should NASA do in practical terms? First, expand robotic exploration of the solar system. With the money saved by cancelling the Space Shuttle, the US - with input from Europe and perhaps India and China - could send a series of flagship missions to Mars, Europa (a moon of Jupiter) and Titan (a moon of Saturn) to look for life. The European Space Agency is building an ambitious new probe to explore the Jovian system. This was originally meant to be a joint mission with NASA, but the Americans pulled out, a move that should be reversed.
Second, NASA should wriggle out of its commitment to the International Space Station, a $100 billion, orbiting white elephant. Congressional law now demands NASA continues to support this exercise until 2017. In May, a private spacecraft called Dragon successfully docked with the space station, showing commercial space flight can be a reality. Since SpaceX's Dragon capsule can carry people, NASA should effectively privatise the whole ISS enterprise - and the whole business of getting men and material into orbit. Turn the station into a hotel, get it sponsored by McDonald's; anything, really. Private enterprise may even manage to make it interesting.
With yet more funds saved, NASA should build a fleet of space telescopes. In terms of value for money, few machines can compete with the Kepler observatory. At a cost of $600 million (about the price of one Space Shuttle launch) this machine has revolutionised our view of the cosmos. In three years it has found more than 2000 ''exoplanets'' orbiting nearby stars, including dozens that are roughly Earth-like in size and temperature. Twenty years ago, we did not know of a single exoplanet; now, it is estimated that there are at least 30,000 potentially habitable planets within 1000 light years of Earth - places such as Kepler-22b, a world bigger than our own yet with similar surface temperatures and possibly a huge ocean covering its surface.
We need more Keplers, and bigger ones. Large space telescopes, or fleets of space telescopes, placed either in Earth's orbit or at the solar system's gravitational oases (known as the Lagrange points) would allow us to survey nearby Earth-like planets, sniffing their atmospheres spectroscopically for oxygen, methane, water vapour and the like - the tell-tale signs of a biosphere. With a really big telescope, we could theoretically see the dark-light colour changes that may signify continents and oceans passing as the planet rotates.
This does not mean, however, that human space exploration should cease altogether. A return to the moon makes sense, not least because the lunar far side is an ideal place to build extremely large telescopes that could explore the surfaces of ''Earth twins'' even more effectively. And if Mars looks promising, it remains the case that a human astrobiologist could achieve in a week what the best robot could do in three years.
Yet concentrating on a search for life would have the advantages of being scientifically valid, being relatively cheap and connecting with the public imagination. Since 1972, Americans have spent far more money making and watching movies about fictional aliens than they ever spent actually going into real space. Looking for ET will garner rather more enthusiasm than growing cress seeds in orbit. And there is a case for devoting modest public funds in the search for alien radio signals.
There remain scientifically and culturally valid reasons to maintain a human presence in space, not to mention more nebulous justifications such as vicarious excitement and national pride. But NASA should leave the flag-planting, for now, to the privateers and to other nations (the next humans on the moon will be Chinese, arriving in the late 2020s).
Go looking for life, and it may well find it. Once it does, all bets will be off - and NASA might just get the money to do whatever it wants.
Michael Hanlon is the author of The Worlds of Galileo and The Real Mars.