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NASA prepares to boldly go

October 24, 2002

Written by Pat Dasch, Houston

EVER since astronauts last set foot on the Moon in 1972, the world has been waiting for a grand vision of humanity`s next foray deep into space. Our visits have been restricted to the space stations barely 400 kilometres above the Earth`s surface and, burdened with the spiralling costs of the International Space Station, NASA has kept silent about the future.
But now it has become clear that the agency never stopped dreaming of sending people into the unknown. Last week, without fanfare or any grand announcement, it quietly unveiled its blueprint for the future. It calls for a space station close to the Moon that will ultimately serve as a gateway for missions all over the Solar System.

The NASA Exploration Team (NEXT), which was set up by NASA three years ago to dream up a future for human space exploration, shared its vision with aerospace experts at the World Space Congress in Houston, Texas. The plan could not be in starker contrast to the politically motivated Apollo missions of the 1970s, or the aimless, cash-guzzling International Space Station. This time the science will come first, promises Gary Martin, NASA`s Future Technology Architect and head of NEXT.

Martin says he took as his starting point the questions most important to scientists, for example how did the Solar System evolve? Has there ever been life on Mars? Are there are any Earth-like planets circling nearby stars? The team then considered what kind of missions would be needed to find the answers.

The proposed first step is to develop huge space-based telescopes able to look back to the early Universe, and out to neighbouring stars in search of other solar systems and Earth-like planets. These would be a "third generation" of telescopes after Hubble and the recently approved James Webb Space Telescope (JWST), due for launch in 2010.

NEXT concluded that the best locations for these new telescopes would be at oases in space called "Lagrangian points". These are points where the gravitational pull of two bodies, such as the Earth and the Moon, cancel each other out, providing a stable location to position spacecraft.

To beat the performance of Hubble and the JWST, these new instruments will need mirrors over 10 metres across. That makes them far too large to launch into space in one piece, and to get around this problem the team has come up with two alternatives. One is a revolutionary "gossamer" design of a flexible, lightweight material that folds up for launch, then automatically unfurls once in position. The other is a more conventional design that would be constructed in space by humans helped out by robots. Either way, the telescopes would have to be serviced and tended by people.

That will require humans to take up residence farther from the Earth than ever before. The team suggests setting up an inflatable space station more than 300,000 kilometres into space, at the L1 Earth-Moon Lagrangian point, to house astronauts while they assemble and service the telescopes (see Graphic). The instruments could be assembled at the L1 point before being sent off to their final destinations. These might include the L2 point just beyond the Moon, or the Earth-Sun L2 Lagrangian point more than a million kilometres beyond Earth`s orbit.

The station would also be a gateway for human missions to the rest of the Solar System, providing a haven where crews could prepare and train before departing to the Moon, nearby asteroids or other planets.
Scientists are still itching to get to Mars, especially since the Mars Odyssey probe discovered what looks like vast amounts of water frozen beneath the planet`s surface (New Scientist, 9 March, p 9). The balanced gravitational pull at Lagrangian points makes travel between them extremely efficient, so craft travelling via an outpost at L1 could take advantage of these low-energy "superhighways" to all kinds of distant destinations.

It`s a grand vision. But for now, a vision is all it is, with no realistic budget or schedule. NEXT has a mere $4 million per year, and NASA has no hope in the foreseeable future of persuading Congress to release the huge funding it would take to make the plan a reality. So NASA is doing all it can - setting out its goals and preparing the ground for future missions by identifying which technologies need to be developed to make those missions happen. As Martin puts it, it`s a "stepping stone" approach.
One core issue the team has identified is the cost and reliability of space transportation. Projects are already under way at NASA to develop successors to the space shuttle for getting crews and craft into orbit. And a separate programme began early this year to develop nuclear propulsion systems, which should be much faster than rocket engines.

Crew health and safety is another key concern. Research carried out on the ISS since 2000 into the impact of long-duration space flight on human health has identified more than 55 potential health risks. It is becoming clear that bone loss, muscle atrophy and effects on blood pressure will be serious problems for astronauts spending long periods in low gravity, so NEXT is looking at designs for spinning spacecraft that would create artificial gravity for crews travelling to Mars.

Then there`s the radiation. When we venture completely out of the Earth`s protective magnetic field, radiation levels are likely to be at least three times those on the ISS. But current shielding technologies may never be up to the task of protecting astronauts spending long periods of time in such conditions (see story, right).

Some observers are sceptical about the new plans, pointing out that NASA`s current financial crisis leaves it in no position to be thinking about sending anyone anywhere. "They first need to get their managerial and technological house in order," says Leonard David of the space.com website.

Others argue, however, that the agency needs a grand vision in order to survive. "Right now, NASA is just one big accounting problem," says John Pike of the Global Security think tank in Washington DC. "Unless there is some other reason for its existence, some other goal, the easiest way of solving this problem is to shut down NASA." And using a space station at L1 as a springboard for wider missions makes sense. "It`s the cheapest thing they could do to get beyond low-Earth orbit. For just a modest technical risk and a manageable budget, they could do it."

The late Wernher von Braun, the genius behind the Apollo missions, would probably have approved. More than 50 years ago, he developed many of the concepts being embraced by NEXT. Instead of the succession of self-contained projects NASA has preferred so far, the new strategy will be one step at a time- much closer to the steady progression von Braun anticipated.

http://www.newscientist.com">New Scientist issue 27th October 2002

PLEASE MENTION NEW SCIENTIST AS THE SOURCE OF THIS STORY AND, IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO : http://www.newscientist.com"> http://www.newscientist.com

New Scientist