Likelihood of contacting Philae "getting close to zero"
According to Rosetta'sscience team, hostile surface conditions prevailing on the comet67P/Churyumov–Gerasimenko (67P) have rendered any hopes ofre-establishing communications with the Philae lander negligible.
"The chances forPhilae to contact our team at our lander control centre areunfortunately getting close to zero," explains Stephan Ulamec,Philae project manager at the German Aerospace Center, DLR. "We arenot sending commands any more and it would be very surprising if wewere to receive a signal again."
Philae's silence comesas a result of its initial descent to the surface of 67P on Nov. 12, 2014. Alongside coping with a faulty thruster, the onboard harpoonstasked with driving into the ground and securing the lander on thecomet's surface failed to fire.
This resulted in Philaebouncing off the comet and impacting a further four times over a twohour period, before finally coming to rest over a kilometer away fromits designated landing point in the Adybos region of 67P.
Unfortunately, it soonbecame clear that the probe's resting place left it lacking thenecessary sunlight needed to power itself, and a frantic race againstthe clock began as Philae's science team attempted to squeeze as muchdata as possible from a host of onboard experiments before theprimary battery died.
Philae succeeded incompleting an impressive 80 percent of its initial planned scientificactivities before slipping into a deep hibernation on Nov. 15, 2014.
Despite this setback,the team at ESA remained cautiously optimistic that as 67P drewcloser to the Sun, Philae may receive enough sunlight to warm up thelittle lander and allow it to recharge its depleted batteries.
Philae awoke once moreon Apr. 26, 2015 but was unable to contact the Rosetta orbiter untilJune 13. A series of sporadic communications followed, however due toa combination of suspected complications including dust obscuring thesolar panels and failure of the lander's transmitters and receivers,Philae fell silent for what is most likely the final time on July 9, 2015.
As the comet activitystirred up by perihelion recedes, Rosetta can once again approachclose to the comet's nucleus, potentially allowing the orbiter topinpoint the location of its silent partner.
However, as ESA is nolonger sending commands to the Philae, and the comet's increasingdistance from the Sun lowers surface temperatures below theoperational threshold, it is incredibly unlikely that the probe willre-establish contact.
Even so, Rosettascientists are planning to have the orbiter listen out for its silentcompanion leading up to the finale of its mission, which willculminate in the spacecraft attempting to perform its own landing onthe surface of 67P in September this year.
Scroll down to view a computer rendering of Philae's traumatic journey to its final resting place.