"Rosetta" will become the first spacecraft to ever orbit a comet. It is due to circle a comet called Churymov-Gerasimenko for some two years, mapping its surface and examining its nucleus. The orbiter is carrying 11 different scientific experiments onboard.
The rocket carrying the "Rosetta" mission had been due to blast off last week from French Guiana but was canceled due to bad weather and technical problems. It is now due to lift off tomorrow around 0800 (Prague time).
Andrew Coates works at the Mullard Space Science Laboratory at University College in London and has been involved with developing some of the experiments on "Rosetta." He explains the enormous challenges of the 1 billion euro ($1.2 billion) mission.
"It's a very interesting mission because, of course, it's got to go a long way. It's got to rendezvous with the comet when the comet is at about 600 million kilometers away from the sun. It has to basically catch up with the comet and match its speed almost exactly, because it's going to go into orbit around the comet and then, of course, a lander will land on the comet's surface," Coates said.
Why explore a comet? Comets formed at the same time as the creation of the solar system, some 4.5 billion years ago. It is believed they may have contained organic matter that helped life develop on Earth. Scientists hope that some of this material may still be frozen in the comet.
Coates says it will take "Rosetta" 10 years to reach the comet but that it won't be sleeping on its way there.
"There are some interesting things which it does on the way. It goes a bit of a scenic route around the solar system. It passes the Earth three times, and it passes Mars as well, and in fact there are a couple of asteroids which it passes on the way," Coates said.
Alistair Scott is the director of communications at Britain's Astrium consortium, which helped build "Rosetta." He explains the mission's unusual name.
"It was named the 'Rosetta' mission because it really will unlock some of the key factors, the key elements, we need to actually understand, first of all, about how our universe came into being and how life possibly evolved on the planets," Scott said.
The original "Rosetta" was a stone tablet found in Egypt that contained parallel inscriptions in three ancient languages. The stone became the key to deciphering ancient Egyptian hieroglyphs. The comet lander has been named after the River Nile island of Philae, where the stone was found.
Scott says "Rosetta" is truly an international mission.
"We had responsibility for all of the design of the structure and the systems of the spacecraft, and we actually developed and built the propulsion system ourselves. But there have been a lot of other people involved in this program throughout Europe -- and, in fact, partly in the U.S.A. -- and a lot of the universities and a lot of smaller companies have provided us with instruments and, of course, are going to do the scientific research," Scott said.
The "Rosetta" mission involves contributions from 14 European countries and the United States.