The Rosetta mission is one of the largest undertakings to date for the European Space Agency (ESA). The asteroid chasing mission was first approved almost 21 years ago, in November 1993. After a few delays, it launched in March 2004 and since then has travelled four billion miles. This Wednesday, if all goes according to plan, Rosetta will catch up to its target Comet 67P/Churyumov-Gerasimenko.

Comet 67P/Churyumov-Gerasimenko is named after its discoverers, Klim Ivanovych Churyumov and Svetlana Ivanova Gerasimenko who first observed it in 1969. The two and a half mile wide comet completes its orbit every six and a half years, with an orbit that extends past Jupiter at it’s farthest point and between Earth and Mars at its closest point.

Rosetta‘s route to the comet has taken it around the Sun five times and around Earth three times as it built up speed to reach its target. The ESA space craft was awoken from a 957 day hibernation in January, to prepare for its mission.

On Wednesday, August 6, Rosetta will go into orbit and send back the closest pictures to date of an icy comet. Then, in November the satellite chaser will make headlines again when it drops a probe, named Philae, onto the comet to send back more photos and take samples of the surface.

“For the first time, we will rendezvous with a comet, for the first time we will escort a comet as it passes through its closet approach to the sun and — the cherry on the top — for the first time, we will deploy a lander. The rendezvous is therefore a key milestone in the mission,” said Rosetta project scientist Matt Taylor to Space.com.

The Rosetta mission may have commercial as well as scientific value. Several companies have already begun making plans and developing technology for asteroid mining. According to NASA’s Near Earth Object Program (NEO), the asteroid belt between the orbits of Mars and Jupiter may contain mineral value equivalent to $100 billion for every person currently living on Earth, while comets are rich in the resources needed for life such as water and carbon based molecules.

Companies interested in mining in space will be watching closely as Rosetta attempts the first orbit and sampling of a “near earth object”.

Those interested in following Rosettas progress can find photos on the ESA’s Flickr stream, get updates from the Rosetta blog and can follow the mission on social media sites such as Twitter and Google+ by searching the hashtag #Cometwatch.