OrbitalHub

Credits: ESA

On July 10, 2010, the European comet chaser Rosetta will perform the second asteroid flyby of its mission. The first flyby was performed on September 6, 2008, when Rosetta had a close encounter with the asteroid 2867 Steins. Rosetta will skim by the asteroid 21 Lutetia at approximately 3,000 km. The speed of the spacecraft relative to the asteroid will be around 54,000 km/h.

The asteroid Lutetia was discovered on November 15, 1852, by the German astronomer Hermann Goldschmidt. Besides the characteristics of its trajectory, few things are known about the asteroid. From the preliminary observations made by Rosetta, scientists were able to estimate the diameter of the asteroid to 134 km, but the actual shape and composition still remain to be determined.

During the flyby, the spacecraft will operate in a special Asteroid Flyby Mode. This will allow the spacecraft to control its attitude and keep the asteroid in the field of view of the imaging instruments carried onboard.

Rosetta has to follow a complicated trajectory that includes three Earth gravity assists and one at Mars, in order to accelerate to the speed needed for reaching its final destination. The last gravity assist maneuver occurred on November 13, 2009, when Rosetta swung by Earth.

After 6 years into the mission, the systems on the spacecraft are doing very well, and the best is yet to come: the rendezvous with the comet 67/P Churyumov-Gerasimenko in 2014. Rosetta will deploy a small lander on the surface of the comet, and it will continue to fly alongside the nucleus of the comet for more than one year.

OrbitalHub will re-cast the live webstream from ESOC, ESA’s European Space Operations Center, in Darmstadt, Germany. The program starts July 10, 2010, at 20:00 GMT. The closest approach will occur at 20:10:07 GMT. Come back and watch the events unfold!

Credits: ESA OSIRIS Team MPS/UPD/LAM/IAA/RSSD/INTA/UPM/DASP/IDA

On November 13, 2009, at 8:45 AM CET, ESA’s comet chaser Rosetta swung by Earth. Rosetta passed just South of the Indonesian island of Java at an altitude of 2481 km. Its speed relative to Earth was 13.34 km/s. The maneuver provided a boost of 3.6 km/s.

Rosetta’s OSIRIS (Optical Spectroscopic and Infrared Remote Imaging System) narrow-angle camera was used to image the Earth once every hour for 24 hours.

Rosetta will meet asteroid 21 Lutetia in 2010. The final destination of Rosetta is the comet 67P/Churyumov-Gerasimenko, which the spacecraft will reach in 2014. Rosetta will deploy a lander to the surface of the comet, and will also orbit the nucleus of the comet and fly alongside as it heads towards the inner Solar System. Most of the time, the probe will hibernate with the majority of its systems shut down in order to optimize the power consumption.

You can find more information about Rosetta’s swing by on ESA’s Rosetta Blog website.