As the dust settles on Comet 67P—some 300 million miles from Earth—scientists and space enthusiasts around the world celebrated the international effort to intricately study Churyumov-Gerasimenko as a monumental moment in space exploration.
Launched in 2004, the Rosetta orbiter and its travel companion, the Philae lander, set off to the distant reaches of our solar system in hopes of rendezvousing with 67P. Gravity assists from Earth and Mars boosted the spacecraft along the way, before reaching the comet in January 2014.
“I think Rosetta is fascinating because it is a real mission, it is an adventure, and represents the aim of making a dream become real,” said Rosetta Flight Director Andrea Accomazzo. “I think it is one of the few mission, if not the only one, that can be compared to the Moon landing of 1969.”
After landing on the comet, Rosetta continually monitored the comet’s evolution during its closest approach to the Sun. Philae’s descent marked the first ever landing on a comet. Planning to land on the comet’s nucleus was an arduous six-week process, and the flight team had only 90 days to land Philae on the surface, Accomazzo said.
The mission set out in hopes of studying the composition of the comet, while searching for essential elements. The European Space Agency team announced findings of oxygen nitrogen, water and glycine—a key amino acid—on the comet. To date, around five percent of all transmitted data from the mission has been processed, and data processing will continue for years to come.
“Having found rare substances means that we have the pieces of the puzzle we are looking for,” Accomazzo said. “Oxygen is very unstable in space. Having found it means it had been trapped in the nucleus at the very, very early stages of the formation of our solar system. Sometimes we thought of comets as the left overs from the formation, but maybe they are the trigger of the formation.”
The results point towards the comet being born in an extremely low temperature nebula more than 4.5 billion years ago. The team is not ruling out the object’s possible Oort Cloud origins following its initial formation.
Tasked with the mission’s final act—strategically sending the orbiter onto the comet’s surface—Accomazzo and his flight team worked to plan the descent, while maximizing data retrieval.
As the orbiter plummeted towards its final resting place, the flight team used the spacecraft’s mass spectrometer to “sniff” the comet’s environment. On its way down, the orbiter snapped high-resolution images of the comet’s pits, key areas in studying its origins and internal composition.
All data from the descent was successfully transmitted back to Earth.
“The spacecraft performed absolute nominal throughout the descent till the impact with the surface,” Accomazzo said. “We were a bit worried because we were exploring regions we had never been to before, and the spacecraft was not designed for it.”
As the orbiter and lander rest quietly on the comet, dust will slowly cover the spacecraft’s solar panels, depleting on-board batteries. This will ultimately prove fatal to the spacecraft’s computer and electrical systems, Accomazzo said.
“Rosetta has been indeed much more than a science mission,” he added.
Mr. Andrea Accomazzo started as a design engineer on Philae’s subsystem in 1997. In 1999, he joined ESA as the spacecraft operations engineer for Rosetta. Two years after the launch, he took over as spacecraft operations manager in 2006. He became flight director in 2014.
Comet 67P is currently headed out beyond the orbit of Jupiter at over 84,000 miles per hour.