Europe’s Rosetta mission becomes the first spacecraft in history to rendezvous with a comet

After 10 years spent traveling more than 6 billion km through space, Europe’s Rosetta mission has arrived at its destination – 67P/Churyumov-Gerasimenko – becoming the first spacecraft in history to rendezvous with a comet.

Flying some 405 million km (250 million mi.) from Earth, Rosetta is now ready to swivel into an elliptical orbit around 67P/Churyumov-Gerasimenko, where it will spend the next two months searching for a landing site for the mission’s small Philae robotic probe.

“After 10 years, five months and four days traveling towards our destination, looping around the Sun five times and clocking up 6.4 billion km, we are delighted to announce finally ‘we are here,’” says Jean-Jacques Dordain, director general of the European Space Agency (ESA), which is leading the Rosetta mission along with prime contractor Airbus Defense and Space.

With Philae expected to descend to the comet’s surface in early November, the orbiter and lander will spend more than a year studying primary material from 67P/Churyumov-Gerasimenko that could give scientists a glimpse at what the Solar System looked like more than 4.6 billion years ago.

Since its 2004 launch atop an Ariane 5 rocket from the Guiana Space Center in Kourou, Rosetta has made three gravity-assisted flybys of Earth and one of Mars on its way to rendezvous with the comet. This complex trajectory has seen Rosetta pass by the asteroids Steins and Lutetia, obtaining unprecedented views and scientific data on both.

After waking from deep-space hibernation at roughly 9 million km from 67P/Churyumov-Gerasimenko in January, Rosetta spent the past seven months activating 11 scientific instruments aboard the spacecraft and another 10 riding on the small lander it is carrying.

The Aug. 6 rendezvous saw the last of a sequence of 10 orbital maneuvers that began in May to adjust Rosetta’s speed and trajectory in line with those of the comet, slowing from 775 meters per second to just 1 meter per second.

ESA says each of these maneuvers was critical, and that had any one failed, the rendezvous would have been impossible.

“Today’s achievement is a result of a huge international endeavor spanning several decades,” says Alvaro Gimenez, ESA’s director of science and robotic exploration. “We have come an extraordinarily long way since the mission concept was first discussed in the late 1970s and approved in 1993, and now we are ready to open a treasure chest of scientific discovery that is destined to rewrite the textbooks on comets for even more decades to come.” Full story at aviationweek