The European Space Agency’s Rosetta probe today descended to a mission-ending impact on the comet that it followed for more than two years.
The car-sized probe continued to transmit data as it dove toward the surface of Comet 67P/Churyumov-Gerasimenko, 446 million miles from Earth. When the data stream flatlined, scientists and engineers at ESA’s mission control in Darmstadt, Germany, knew it was all over.
The end was greeted at 1:19 p.m. CEST (4:19 a.m. PT) with a prolonged “Ohhh,” followed by applause and hugs.
“This is it,” said Rosetta mission manager Patrick Martin. “I can announce the full success of this historic descent of Rosetta toward 67P, and I declare hereby the mission operations ended for Rosetta. … Farewell, Rosetta. You’ve done the job.”
— ESA Rosetta Mission (@ESA_Rosetta) September 30, 2016
Rosetta, which was named after Egypt’s famous Rosetta Stone, put more than 4 billion miles on its odometer from start to finish.
The $1.5 billion mission was launched in 2004 and required a decade of travel to get to the comet. Months after it entered a looping orbit around 67P, Rosetta sent down a piggyback probe called Philae to land on the surface and transmit data back.
The hardware that was supposed to anchor Philae to its landing spot didn’t work as intended. Instead, the solar-powered lander bounced along the surface, got stuck, and fell out of contact after just a couple of days. It wasn’t until this month that Rosetta’s team spotted the lander again, wedged in a crevice where it couldn’t recharge its batteries.
The tale of Rosetta and its plucky little lander captured hearts across the world, in part due to a series of cartoons worthy of a children’s book.
Over the past two years, the readings from Rosetta and Philae have filled out scientists’ picture of the comet’s composition and what it says about the early history of the solar system. They determined that 67P consisted of two separate objects that fused together to create its “rubber ducky” shape.
Chemical analysis showed that the comet’s frozen water didn’t match the isotopic fingerprint of Earth’s oceans. However, the ice was found to contain some of the ingredients for life, including an amino acid called glycine.
Rosetta stuck by the comet through last year’s closest approach to the sun, and captured spectacular pictures of gas and dust erupting from the surface as it heated up.
However, as 67P receded back into the darkness, there was less sunlight to recharge Rosetta’s batteries, and communication was expected to become increasingly difficult. ESA determined that today was the right time to bring the mission to an end.
After contact was lost, team members celebrated, and commiserated, at mission control in Darmstadt.
“I feel very proud of our teams for pulling this off,” Rolf Densing, ESA’s director of operations and head of the European Space Operations Center, told his colleagues.
He reminded them that ESA’s Trace Gas Orbiter was due to reach Mars next month for a mission that would include sending a mini-probe called Schiaparelli to the Red Planet’s surface.
“The best way to fight off depression is to look ahead,” Densing said. “There’s life beyond Rosetta. As great as it was, we will be back for a landing on Mars.”