The European Space Agency captured the world’s imagination with the landing of the Philae lander on Comet 67P / Churyumov-Gerasimenko on November 12. Excitement wavered to disappointment after the Rosetta team realized the Philae lander didn’t land properly.
The anchoring harpoons failed to latch onto the surface, and the probe bounced back towards space. Philae bounced a second time before coming to rest at the base of a cliff wall. Two of its three legs were on the ground.
Despite not having an ideal landing, Philae still knocked out 64 hours worth of experiments.
ESA officials thought that might be the last time we ever heard from Philae. The cliff wall obstructed much-needed sunlight for the Philae probe to power up.
Over the weekend, Philae woke up and communicated twice. After eight months of silence, Philae’s Twitter account buzzed:
Hello Earth! Can you hear me? #WakeUpPhilae
— Philae Lander (@Philae2014) June 14, 2015
“We are still examining the housekeeping information at the Lander Control Centre in the DLR German Aerospace Center’s establishment in Cologne, but we can already tell that all lander subsystems are working nominally, with no apparent degradation after more than half a year hiding out on the comet’s frozen surface,” says DLR’s Stephan Ulamec, Philae Lander Project Manager.
During peak sunlight, Philae’s power levels sit at 24 W. That’s more than the 19 W required to power the transmitter.
Getting Rosetta closer to Philae
The key to resuming experiments with Philae is establishing stable communications. “It’s of utmost importance to see if we can get a stable communications pattern between the two machines,” said Rosetta deputy flight director Elsa Montagnon at a recent press conference.
“If we can do that, then we can do the next step and resume the scientific operation of Philae,” she added.
Sounds simple, right? Far from it. Comet 67P is just two months away from its closest approach to the Sun. The amount of ice, gas and dust spewing from Comet 67P increases with each passing day. Here’s how Comet 67P looked on June 7.
Rosetta’s distance from the comet varies between 220-240 kilometers.
To receive data, Rosetta needs to move its orbit to around 180 kilometers from the comet.
ESA officials are willingly to risk moving Rosetta closer right now before the comet becomes even more active.
Why risk it?
Philae has a unique opportunity here. It can study Comet 67P as it undergoes dramatic changes due to heating from the Sun.
And, Philae’s bouncy landing made it all possible. If Philae hit its planned landing zone, its instruments would likely already have overheated. Instead, Philae is perched in a shadow that will protect it from heat for a lengthy period.
Scientists have a chance to conduct experiments they never thought they would. It’s worth the risk.
Image credits: ESA