Many moons ago, a small space probe named Philae skipped across the surface of Comet 67P/Churyumov-Gerasimenko when the lander’s harpoon-like anchoring mechanism failed. It came to rest in a shady spot and, without enough sunlight to keep it powered, it fell asleep after about 60 hours of operation.
Mission scientists had been trying to pinpoint its location since November — until late Saturday.
At 10:28 p.m., the European Space Agency’s operations center in Darmstadt, Germany, just south of Frankfurt, received a signal from Philae, which transmitted more than 300 data packets. Those have been analyzed at the Lander Control Center at the German Aerospace Center, which dubbed Philae’s emergence from its seven-month slumber a “‘hello’ from space.”
“Philae is doing very well. It has an operating temperature of -35ºC and has 24 watts available,” Philae project manager Stephan Ulamec said in a statement. “The lander is ready for operations.”
To hear Twitter tell it, Philae’s comet-chasing mothership, Rosetta, was delighted to hear from the little lander but reluctant to let it delve back into work too hastily after its long sleep.
“Hello @ESA_Rosetta! I’m awake! How long have I been asleep? #Lifeonacomet,” came the tweet from Philae’s handle.
“Hello @Philae2014! You’ve had a long sleep, about 7 months!” Rosetta responded.
“Wow @ESA_Rosetta! That’s a long time… time for me to get back to work! #Lifeonacomet”
“@Philae2014 Need to check you’re fit, healthy and warm enough first @philae2014! Take it easy for now :)”
“Oh, OK @ESA_Rosetta! I’m still a bit tired anyway… talk to you later! Back to #lifeonacomet!”
Months after Philae nodded off, lander system engineer Laurence O’Rourke told CNN that Philae needed almost 6 watts of power to reboot itself, 9 watts to accept communications and 19 watts to allow two-way communication with the orbiter — not a great deal of power when you consider energy-saving lightbulbs use 20 watts or fewer.
SOURCE: Eliott C. McLaughlin and Dave Gilbert