For the first time since contact was lost with the Philae probe on Comet 67P (67P/Churyumov-Gerasimenko), the Rosetta mothership is aligned with its approximate landing site and the comet – and hopefully the probe – are getting hit by enough of the sun’s rays to deliver some charge to the solar batteries. Will little Philae wake up?
Philae was last heard from on November 14, 2014, two days after it bounced upon landing and ended up leaning against a rock or cliff that blocked most of the solar rays its batteries need (photo above shows what is believed to be the first landing spot and final location), After sending pictures for two days, Philae ran out of juice and shut down in a power-saver mode to wait for its batteries to be recharged to the point where it can begin communicating again.
Based on its projected location, Philae should be getting about 1.3 hours of sunlight every 12.4-hour, the length of the comet’s day. It needs 5.5 watts of power and an internal temperature of at least minus 45 degrees Celsius (minus 49 degrees Fahrenheit) to wake up and 19 watts of power to transmit to Rosetta.
On March 12, Rosetta and Philae were aligned for communications and the DLR Lander Control Center in Cologne, Germany, began sending signals. As of this writing, nothing has come back, according to Koen Geurts, the Philae team’s technical manager.
At this time, we do not yet know that the lander is awake. To send us an answer, Philae must also turn its transmitter – and that requires additional power.
Mission control has until March 20th to establish a link. After that, Rosetta and Philae will be out of alignment. Here’s what Geurts hopes happens if they connect.
We will then evaluate the data. What is the state of the rechargeable battery? Is everything on the lander still functioning? What is the temperature? How much energy is it receiving?
If the connection is made, Geurts and his team will get as much data as they can from Philae until it shuts down again. If there’s no connection, they will continue to try when the probes are again in alignment until August 13th when 67P enters orbit around the sun, leading to the end of the mission in December.
Until then, we wait and hope for Philae to wake up.