Trip to the Moon on Sun's Energy
By Julio Godoy
The director of the first European mission to the moon explains to Tierramérica how a light, refrigerator-sized probe may transform space travel as we know it. The SMART-1 was launched Saturday.
PARIS, (Tierramérica).- The first lunar space mission, SMART-1 is underway, with the mission of analyzing the chemical make-up of unexplored regions of the Earth's natural satellite, and employing new miniature techniques, like ionic solar propulsion, which could be the technological basis for future space exploration.
On Saturday, the spaceship SMART-1 (Small Missions for Advanced Research and Technology) was launched into space by an Ariane 5 rocket, from the European Space Agency's base in Kourou, French Guyana, on the Brazilian border.
For the next few months, SMART-1, guided by scientists on Earth, will travel towards the moon, entering its orbit in December 2004 and, with the aid of new miniature technology, observe the moon's surface, particularly its southern pole.
In a Tierramérica interview, project director Giuseppe Racca explained that "at first our plan was determined by one restriction and one freedom: we had little time to design a new space research project, which also meant little money, but, given that the European project had no precedents, we didn't have to integrate a burdensome legacy into our plans."
With just four years in development, the SMART-1 probe is the outcome of these two factors.
Costing a relatively modest 125 million dollars, it has an elegant design, is about the size of a refrigerator, less than a cubic meter in volume, and weighs just 367 kilos.
Thanks to miniature technology, the precision instruments needed for lunar exploration all fit into this reduced space.
SMART-1 is so small and light that it shared the Ariane launch rocket with two satellite missions.
According to Racca, one of the great innovations of the probe is the use of dual, or solar ionic propulsion, utilizing the sun's energy to feed ionic engines.
"The ionic motors expel electrically charged particle -- ions -- producing a force in the opposite direction, which moves the spaceship," explained the scientist.
"The electricity necessary to feed the engines comes from the sun's rays, which SMART-1 captures and transforms into energy through the special panels on its wings."
These engines are extremely efficient, producing 10 times more power per kilo of fuel than those commonly used in space travel.
The dual ionic technology would be applicable for space missions within the solar system, where the sun can provide the needed energy.
And in the near future, for trips beyond our system, where the solar energy is weak, the dual propulsion system could include nuclear engines as a substitute for the sun, says Racca.
But in this first European mission to the moon, the technique will be put to a very difficult test.
"SMART-1 will gradually approach the moon, but will have to counteract the its gravitational pull, until reaching a specific orbit in December 2004. The path is very complex, such that ionic solar propulsion will be put to the test in extremely difficult conditions, comparable to a trip into deep space," he said.
Another innovation is the use of high-definition infrared cameras. "These cameras measure visible light with a definition of a million points in a five-degree field of vision, with filters capable of selecting yellow, red or infrared light," said Racca.
"The cameras will observe select regions of the moon from different angles and under different lighting, which will give us clues as to the way this satellite of the Earth has evolved with the passage of time."
Other SMART-1 technology includes the infrared spectrometer, capable of detecting rare minerals or revealing the details of craters formed by meteorites hitting the moon.
Beginning in December 2004, when the probe will begin its orbit of the moon, it will send photographic images to the Kourou space center, particularly about the Aitken Basin, an enormous crater at the moon's south pole, created by a giant meteorite.
"The lunar surface full of craters provides an image of the Earth's surface some four billion years ago, an era when comets and asteroids continuously rained on the recently created solar system," he explained.
The craters the asteroids left in the Earth's crust disappeared with the evolution of the planet, but the moon has not changed in nearly 3.5 billion years.
Another of SMART-1's objectives is to compare the mineral composition of the two celestial bodies -- the Earth and the moon -- to confirm their shared origins.
The infrared photography will allow scientists to map out the mineral make-up of the moon. "We will be able to conduct the first exhaustive mineral and chemical inventory of the unexplored regions of the moon and compare it to that of the Earth," said Racca.
One of the theories favored among scientists is that when the Earth was still a young planet, a collision with a gigantic meteorite broke it in two. The larger became the Earth we inhabit today, and the smaller is the moon.
"SMART-1 is going to open new horizons. And we will share these discoveries with the whole world, with news and photographs each day," promised the mission chief.
* Julio Godoy is an IPS correspondent.