Een klein ruimtevaartuig met "Star Trek"-achtige technologie staat vandaag op de drempel van de maan, en kan een mijlpaal zijn in de geschiedenis van de Europeese ruimtevaart
Komende maandag zal SMART-1 zich in een baan rond de maan manoevreren, en daarmee het eerste ruimtevaartuig van de ESA zijn dat de maan bereikt.
Maar het 370 kilo zware, 100 miljoen euro kostende vaartuig is mee dan een gewone sonde met sensoren en camera's.
Het belangrijkste doel van SMART-1 (wat staat voor Small Missions for Advanced Research and Technology) is om state of the art technologie te testen, en zo de weg vrij te maken voor toekomstige missies naar de maan, en wellicht zelf colonies op de maan.
Along the way it will not only demonstrate a revolutionary new propulsion system, but make the first comprehensive map of elements on the moon’s surface.
SMART-1, launched by an Ariane rocket from Kourou, French Guiana, on September 27 last year, is about the size of a refrigerator with long solar panels spanning 46 foot.
Electricity from the panels is used to power the spacecraft’s ion engine. Instead of using a chemical rocket, SMART-1 fires a high-speed stream of electrically charged atoms of Xenon gas.
A similar idea was used by the makers of Star Trek as part of the Starship Enterprise’s propulsion system.
Although the thrust produced is minute, only amounting to about a quarter of an ounce, it can be maintained over long periods of time.
The slow acceleration can eventually push SMART-1 to speeds of almost two miles per second and beyond.
Travelling in a series of widening spirals, the spacecraft picked up extra speed from the Earth’s gravity, reaching a maximum of five miles per second.
Today it crossed the crucial “langrangian point” where the gravitational fields of the Earth and moon balance out.
Professor Bernard Foing, ESA’s chief scientist and SMART-1 Project Scientist, said at a briefing in London today: “At the moment SMART-1 is only at the gateway. We are not yet there.
“Symbolically it’s important, because it’s the first time that western Europe has a mission that is more attracted to the moon than the Earth.”
SMART-1 is now about 41,540 miles from the moon. On Monday, at a distance of about 31,000 miles, it will start applying the brakes. The ion engine will fire continuously for four days as the spacecraft begins to spiral down towards the moon.
Eventually it will reach a stable elliptical orbit ranging from 1,860 miles to 186 miles from the moon’s surface.
SMART-1 carries a battery of sophisticated instruments including a camera with the ability to peer into the moon’s most shadowy regions.
British scientists provided one of the most important instruments, the D-CIXS – a super-compact X-ray spectrometer.
The device, no bigger than a small toaster, will be used to analyse the composition of the moon’s surface by looking at the “colour” of X-rays reflected off it.
It will provide scientists with the first ever global map of the elements that make up the surface of the moon.
The Apollo missions in the 1960s and 70s only analysed about 10% of the lunar surface.
Scientists hope the results will provide important clues about the origin of the moon, and information that can assist future robotic and manned missions.
One target for the spectrometer is the biggest impact crater in the Solar System – a massive hole in the moon more than 2,000 miles across on its far side.
By looking down the hole, it should be possible to analyse the composition of rocks deep within the moon’s interior.
SMART-1 will also search for water that is thought to lurk at the bottom of the moon’s darkest and coldest craters, and material that could be used for building bases.
Professor Manuel Grande, D-CIXS lead scientist from the Rutherford Appleton Laboratory near Oxford, said: “There are deep craters which haven’t seen the sun for many billions of years. At the bottom of these craters we believe there are reservoirs of ice. These reservoirs of ice could be used by astronauts to maintain themselves on the moon.
“Another thing you need is building blocks. You need to find bits of the moon that are good for turning into concrete for building your lunar base.”
He said information from SMART-1 would also help to clear up the mystery of how the moon formed.
The most accepted theory is that early in its history, more than 4.5 billion years ago, a large body as big as Mars smashed into the Earth.
The impact sent debris flying into space, some of which formed an orbital ring which condensed to create the moon.
Bron:
http://www.seti-nl.org