It's been a mission ten years in the making, and after a final green light from mission control tonight, the European Space Agency's (ESA) Rosetta Mission will deploy its handy little lander named "Philae" onto the surface of the far off Comet 67P/Churyumov-Gerasimenko it met up with earlier this summer.

Since its inception, the priority of the mission was to reach the comet and discover what information may lie beneath the icy surface. And in turn, what it may tell us about our 4.6 billion-year-old solar system and how we came to be.

While the mission has been successful thus far in arriving and collecting data from a distance, as it orbits the comet a mere 22.5 km away, the next branch of the mission involving the Philae Lander will give researchers an entirely new view of the surface and the composition of the mysterious comet.

"Comets are new territory" researcher Ralf Gellert with the University of Guelph says. "There could be some big surprises."

As a founding member of Rosetta Mission's development team, Gellert was one of the few scientists selected worldwide by the ESA 15 years ago to build instruments that will be used in a few mere hours to collect data that could change what researchers know about comets to date. But even the early stages, much like what mission control is feeling today, were filled with uncertainty as the ESA crossed new frontiers being the first space agency to not only orbit, but also land on a comet.

"Is it an ice ball with rock and trace metals, or a rock ball with ice on it... or ice below the surface?" Gellert says. "We didn't know."

But the researchers planned for the contingencies of a myriad of possibilities, and now their planning is about to pay off. While models have planned and calculated an exact trajectory for the Philae lander, the ESA admits that the maneuver comes with plenty of variables and a high-risk level for failure. But that's not discouraging them one bit.

After a final run-through of the plans late this afternoon, the ESA mission control will confirm plans with Philae Tuesday night Nov. 11 to detach from Rosetta and make the short trip to its landing site on the smaller head of Comet 67P. If all goes to plan, Philae will land with all 11 on-board scientific instruments intact, and will be able to begin specimen collection and data transmission after it's settled into the surface of the speeding comet.

"We will need to be a bit lucky" flight director Andrea Accomazzo and project scientist for the mission Matt Taylor said earlier this week at a briefing for the ESA. "But this is what Rosetta is there to do; to see how a comet works."