I have great news to share with you this Sunday morning. Yes, you read that right — the comet lander Philae is alive and well. On Saturday at 3:28 p.m. CDT, the lander “spoke” to the mothership, the Rosetta spacecraft in orbit about Comet 67P/C-G, for 85 seconds, exchanging 300 “packets” of data.
“Philae is doing very well. It has an operating temperature of -35ºC (-31F°) and has 24 watts available,” said DLR Philae Project Manager Dr. Stephan Ulamec. “The lander is ready for operations.”
Rosetta has been listening for Philae’s radio signal since March 12 in hopes that the changing orientation of the comet coupled with an increase in the intensity of sunlight as it approaches the Sun would fire up the lander’s solar panels again.
Philae briefly touched down on 67P on November 12, but the harpoons used to anchor it to the comet’s surface failed. The three-legged lander bounced right back into space and sailed above the nucleus for two hours before settling down (after two more bounces!) at a new landing site called Abydos about a half mile from the original site.
Unfortunately, Philae settled down in a shaded area at the base of a large cliff. Without enough sunlight on its solar panels, to re-charge its batteries, the probe went into hibernation 60 hours later. Not only did we lose contact, we lost sight of the lander. Recently, a promising candidate was found on extreme close-up photos taken when Rosetta was in close orbit about the comet.
Throughout the mission, the Rosetta team has never given up hope that Philae might regain its strength and wake up. That it actually happened is incredible.
Now the scientists are waiting for the next contact. There are still more than 8000 data packets in Philae’s mass memory which will give the mission team information on what happened to the lander in the past few days on the comet. Surprisingly, the lander appears to have woken up even earlier, since it also sent along older, historical data.
I don’t know about you, but this morning’s news made for a wonderful wake up call. And now that the Sun’s starting to come out here, I kinda have a feeling about how it feels to be Philae today.
* UPDATE: In the coming days, the mission teams will reestablish contact with Philae and increase the amount of time it can “talk” with the lander. Once regular contact is established, science observations can begin again. Slowly. One instrument at a time.
The first instruments activated, those measuring temperature, magnetic fields and electrical conductivity on the comet, make small demands on Philae’s power. Slightly more power-hungry operations like picture taking and radio ranging will follow. Using the images and new data, scientists should be able to pinpoint the lander’s location.
After these steps, mission engineers will attempt to recharge the probe’s drained batteries to fire up its ovens (used to heat samples to determine their composition) and run the drill to collect fresh material.
Here’s a cool link to see LIVE telemetry from Philae.