Editorial: 鈥Right now, science needs the right stuff鈥
ON 26 FEBRUARY, two days after NASA鈥檚 space shuttle Discovery blasted off on its final flight, a plane loaded with researchers soared over Cape Canaveral, Florida, home to the shuttle鈥檚 launch pad, in preparation for a very different era of space science.
These lucky few were training to conduct experiments aboard a new generation of spacecraft built by commercial outfits like .
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The vehicles鈥 primary purpose will be to ferry tourists to the edge of space, about 100 kilometres above Earth鈥檚 surface. But it is the potential to expand research in astronomy, planet formation, and other disciplines that had scientists salivating at a in Orlando, Florida.
鈥淲e鈥檙e entering a regime where the space scientist is going to be able to go into the field the same way that geologists and biologists and oceanographers do,鈥 says Daniel Durda of the (SwRI) in Boulder, Colorado.
On 28 February, SwRI signed the first contracts to fly scientists to space on vehicles made by Virgin Galactic and . The flights are expected to be up and running by 2013 or sooner. When they do, what can we expect to learn from the on-board experiments?
Science has already been done on the International Space Station, the shuttle, satellites and high-altitude balloons. But , who is leading the new programme at SwRI, says that the planned flights, which will include a few minutes of weightlessness, will make a unique contribution.
For starters, he is excited by the prospect of solving an about the moon鈥檚 atmosphere, which began with NASA鈥檚 crewed Apollo missions to the moon in the 1970s. From lunar orbit, NASA astronauts reported complex and unexplained light shows just before sunrise, including shafts of light that appeared suddenly and seemed to radiate from the moon鈥檚 horizon.
Potential explanations include excited sodium atoms in the moon鈥檚 tenuous atmosphere and sunlight glinting from dust particles. Without measurements it is not possible to confirm or rule out these ideas.
In principle, a telescope could do the job, by detecting the wavelength of the light, but it would need to be positioned so that the moon鈥檚 shadow blocks most of the sun鈥檚 light. Short of going back into lunar orbit, the only way to do this is to send a spacecraft into the path of a solar eclipse. That can鈥檛 be guaranteed with existing telescopes in fixed orbits around Earth, nor high-altitude balloons, which drift with the wind. Uncrewed sounding rockets, which launch from fixed sites, are also unsuitable.
Yet it should be relatively simple to pull off with a telescope on either Virgin Galactic or XCOR鈥檚 vehicles, which are designed to be launched at least once a day from ordinary runways anywhere in the world. 鈥淚t鈥檚 a problem that you can solve better with these suborbital vehicles than with any other tools we have,鈥 says Stern, who .
Suborbital vehicles are also ideally positioned to carry out experiments probing the origins of our solar system. The planets formed from dust grains in a nebula that swirled around the infant sun. But it is not clear why colliding grains stuck together to form larger and larger objects, rather than bouncing off each other or shattering, as rocks in laboratories on Earth often do. A simulation in microgravity might give us an answer.
Enter Blue Origin, which also makes suborbital vehicles, headed by Jeff Bezos, founder of Amazon. It has already agreed to fly a suite of dust collision experiments on an uncrewed flight of its New Shepard vehicle, which will carry tourists on other trips.
Containers full of dust grains will float around and collide in microgravity for several minutes as video cameras record their behaviour. By contrast, microgravity only lasts seconds inside drop towers, while a longer-lived dust collision experiment that flew on the space shuttle is expensive and repeated infrequently, making progress painfully slow.
Flights with space tourism companies are expected to be cheaper and more frequent, allowing researchers to tweak and repeat experiments, and to zero in on conditions that produce more interesting results.
鈥淚t flies, it comes back, we look at the data and say, 鈥極h, this points us in this direction鈥,鈥 says l of the University of Central Florida in Orlando, who is heading the project. 鈥淭hen you can come up with a new set of parameters that you鈥檇 like to explore in another flight.鈥
Suborbital spacecraft will allow frequent access to the so-called 鈥渋gnorosphere鈥, a region above the reach of balloons and below the orbits of satellites. The results of these experiments could help improve climate models.
鈥淪uborbital spacecraft will frequent the 鈥榠gnorosphere鈥, which could help improve our climate models鈥
This is also the ideal vantage point for spotting potentially dangerous asteroids that spend most of their time closer to the sun than is the Earth. These tend to be lost in the glare of the daytime sky for ground-based telescopes. of the Planetary Science Institute in Tucson, Arizona, and Luke Sollitt of the Citadel in Charleston, South Carolina, are designing a to do this and other kinds of astronomy.
All of these experiments rely on firms getting their vehicles safely flying to space and back, which is not guaranteed since none of the space tourism vehicles in development have done so yet.
But there are grounds for optimism. Virgin Galactic鈥檚 SpaceShipTwo is closely based von its predecessor SpaceShipOne that safely flew to space and back three times in 2004. Suborbital spaceflight is also easier than the orbital variety in some respects. The vehicles have lower-power engines, need far less fuel and don鈥檛 experience the tremendous heat of re-entering the atmosphere from orbit.
鈥淚 don鈥檛 have any doubt that five years from now, multiple space lines will be operating large numbers of suborbital flights,鈥 says Stern. 鈥淚t鈥檚 going to change things in ways we probably can鈥檛 imagine.鈥
