YOU have probably seen the headlines. NASA’s space shuttle Columbia is nearing the end of its epic 16-day science mission. Seven astronauts, including Israel’s first ever space-goer, have been working round the clock as they orbit the Earth, carrying out over 80 ground-breaking research projects.
The flight has unleashed the agency’s usual stream of breathless claims about scientific research that cannot be duplicated elsewhere, and of dazzling innovations and discoveries just around the corner. We’ve been promised everything from unprecedented views of the ozone layer and atmospheric phenomena to steps toward cures for cardiovascular problems, dizziness and even cancer. What hasn’t been shouted quite so loudly is the fact that the mission is costing around half a billion dollars. Can the science possibly be worth it?
The mission, STS-107, is the first to be dedicated to science in almost three years, and the first to cover such a broad range of subjects. And there’s no doubt it has produced some real results.
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One of the mission’s most intriguing accomplishments is a collection of photographs showing unusual electrical phenomena above thunderstorms, called elves and sprites. Sprites are upper-atmosphere flashes that last just a few milliseconds and spray aurora-like wisps of red ionised gas 20 to 100 kilometres above the Earth. They were first reported in 1989 and almost immediately confirmed by space shuttle observations.
Elves, a strained acronym for “Emissions of Light and Very low-frequency perturbations from Electromagnetic pulse Sources”, were discovered during a shuttle mission in 1995. Even briefer and fainter than sprites, elves have been captured on a scientifically calibrated camera for the first time by STS-107 astronauts.
Israeli physicist Yoav Yair, who is in charge of the observations at mission control in Houston, says the detailed new images will be a boon for theorists studying how the glows are generated. Elves, sprites and related “blue jets” are thought to be a kind of missing link in the atmosphere’s global electrical circuits, and could play an important role in the chemistry of the ozone layer. “This is a direct case of the shuttle leading to a lot of good science,” says Matt Heavner of the Los Alamos National Laboratory, New Mexico, who studies elves and sprites.
With results like this, it isn’t surprising that the often-maligned US space agency is doing all it can to hype the scientific benefits of this mission. After all, science was supposed to be the keystone and raison d’être of NASA’s the International Space Station, its most expensive undertaking since Apollo. But it hasn’t turned out that way – and even some of NASA’s strongest supporters fear that the $15-billion-and-counting ISS may never live up to that promise.
To justify the future of its manned space programme, NASA is under mounting pressure to show the world that useful, significant research can be done in space. But even if the major changes necessary to allow serious science to take place on the ISS are made, they will take several years to implement. In the meantime, the space shuttle and its Spacehab laboratory module are pretty much the only game in town.
The perfect flame
So for the moment all eyes are on mission STS-107. One of the projects on board that has caught the public imagination is a study of fire.
On Earth, the nature of flames is determined by gravity: heated gases rushing upwards create a flame’s dancing, turbulent shape, but make it nearly impossible to study the combustion process in detail. In the weightlessness of the shuttle, flames produce eerie, perfectly symmetrical spheres of very slow combustion. The process is so slow because without the rising gas, there is no inrush of air to feed the flames.
This slow, steady burning has made it possible to produce the weakest flames known. Each “flame ball” in the shuttle’s combustion lab produces about 1/50th the energy of a birthday candle flame, which is perfect for studying the basic mechanisms of heat transfer during combustion. The shuttle team is using five different combinations of gases, and the research might have applications in harnessing combustion more efficiently, for example in the design of low-emission, high-efficiency engines.
The shuttle’s astronauts are also studying ways of putting fires out. This can be a tricky task in zero gravity, and it’s far from just a theoretical problem, as astronauts and cosmonauts who survived some frightening fires aboard the Mir space station can testify. The experiments are designed to find the smallest quantity of water spray that can suppress a fire, to minimise damage to surrounding equipment. The benefits for science back on Earth are less clear, but the results might be relevant to fighting fires in high-tech equipment centres.
Health benefits
It’s the shuttle’s biomedical experiments that are being sold hardest in terms of their impact back on Earth. And there does seem to be a potential for benefits from some of these studies, for example those investigating the growth of certain cancer cells, or the loss of bone and muscle mass in space.
The team is also conducting a study of balance and dizziness. The initial aim is to help astronauts adapt better to weightlessness and the absence of sensory cues for direction. But the results may also improve our general understanding of the neurovestibular system, leading to spin-offs for people with balance problems.
Yet, as interesting and potentially useful as much of the research going on aboard NASA’s space shuttle may be, can it ever be enough to justify the roughly half a billion dollars each shuttle flight costs?
Larry Young, former director of the National Space Biomedical Research Institute in Houston, Texas, and professor of astronautics at MIT is in no doubt. Another series of experiments is investigating how different organisms grow and function in a zero-gravity or low-gravity environment. All life we know about grew and evolved in a constant one-g environment. “The only way to understand the gravitational effects on organisms is to study them without it, which you can only do in space,” Young says.
Otherwise, “to try to do research on the effects of gravity would be like trying to study vision without being able to turn out the lights”. He says that to understand basic biological processes such zero-g work “is interesting, is important, and is worth the substantial portion of our national treasure that we spend on it”.
But while Louis Friedman, executive director of the Planetary Society, based in Pasadena, California, agrees that much of the science being carried out on the shuttle is “certainly worthwhile”, this doesn’t necessarily mean it is worth the money. “Much of the science can be conducted cheaper, faster, better on robotic spacecraft,” Friedman says.
An armada of unmanned craft have been unlocking the secrets of the solar system over the past three decades. Many scientists charge that, in contrast, the human side of NASA’s space programme is yielding little in scientific return while devouring the lion’s share of the space budget. In terms of pure science results, there is little doubt the money would be better spent on more unmanned projects.
But whatever the wisdom of NASA’s past decisions, the space shuttle and the ISS are there, so most researchers take the pragmatic view that we might as well get as much science out of them as we can. “The shuttle was a programmatic disaster for the US,” says Friedman. “We never should have made it our sole access to space.” But since it exists, he told 91av, “the value of doing science on it, at incremental costs, is probably pretty high. I am impressed about how many little, fairly low-cost experiments can be done and how much opportunity is opened up.”
Even Bruce Murray, an astrophysicist at Caltech, and in the past a harsh critic of the expenditures on human space flight, is making the best of the situation. “Rather than debate the absolute cost-effectiveness of such research,” he says, “we should look at what’s special about that environment.”
And there are the less tangible benefits. Friedman notes the symbolism of an experiment on board that is being conducted by a joint team of Palestinian and Israeli students. “Symbolism isn’t all bad – it does motivate and inspire,” he says. “The human programme and the big shuttle flight do capture public interest and serve as a motivator for people.”
