The European Space Agency (ESA) announced that a crucial part of its long-slumbering Rosetta spacecraft—its Philae lander—was successfully reactivated Friday, March 28. This comes over two months after the spacecraft as a whole was “woken up” on Jan. 20 after a sleep period of two and a half years. Rosetta is currently chasing down the comet 67P/Churyumov–Gerasimenko, where it intends to be by Nov. 11 this year. If all goes as planned, Philae will descend to the comet’s surface, where it will take high-resolution photos and samples of its composition, making unprecedented, on-the-spot analyses.
The ESA related that it had woken up the lander up through its host spacecraft. Ground controllers sent a command a week prior to the wake-up, which was executed at 06:00 GMT March 28. A confirmation signal was picked up by Earth at 11:35 GMT. The lander was described as being “alive and well.” More extensive checks of its 11 instruments will take place throughout this month.
The spacecraft’s OSIRIS imaging system recently sent back its first image since its wake-up call, including its intended comet target (see sidebar photo); other spacecraft health checks are currently underway. A previous AmericaSpace article by Ben Evans detailed how the spacecraft was reactivated in January.
This stage of the mission was essential for the Rosetta spacecraft’s next phase, which involves extensive mapping of the comet in August and September. This will aid ground controllers in determining a safe landing site for Philae. At present time, little is known about the comet’s geologic features. Matt Taylor, Rosetta project scientist, communicated his excitement about the spacecraft’s upcoming activities.
“Landing on the surface is the cherry on the icing on the cake for the Rosetta mission, on top of all the great science that will be done by the orbiter in 2014 and 2015. A good chunk of this year will be spent identifying where we will land, but also taking vital measurements of the comet before it becomes highly active. No one has ever attempted this before, and we are very excited about the challenge!” he enthused.
Philae’s primary science mission, according to the ESA, is based on its 64-hour battery life and involves taking hi-res photos, on-site analyses, and drilled samples. However, it does have solar cells to recharge its batteries, which will contribute to the lander’s extended science mission. The Rosetta orbiter is intended to remain alongside the comet for another year, keeping an eye on its activity as it transits the inner and outer Solar System.
Rosetta was powered down for its long sleep on June 8, 2011. During this time, the solar-powered spacecraft journeyed away from the Sun and toward the planet Jupiter. In early January, it was deemed close enough to the Sun to draw power for its systems to be reactivated. Rosetta was launched from the Guiana Space Centre near Kourou, French Guiana, on March 2, 2004.
If all goes as planned, it’s hoped that Rosetta and its associated instruments will show that the conquest of comets is worth the long wait.