Europe’s pioneering Rosetta spacecraft dramatically concluded its 12-year odyssey yesterday, crash-landing into the comet it orbited and probed for two years in a quest to demystify the Solar System’s origins.
There were tears, hugs and cheers at mission control in Darmstadt, Germany when spacecraft operations manager Sylvain Lodiot announced: “This is the end of the Rosetta mission.”
“Rock-n-roll Rosetta,” added a visibly moved Matt Taylor, project scientist, as he left the podium, holding – and shaking – his head.
Rosetta made a “controlled impact” with Comet 67P/Churyumov-Gerasimenko at 1041 GMT – the closing chapter in a project approved in 1993 to look some 4.6bn years back in time.
Comets are thought to contain primordial material from our planetary system’s birth, preserved in a dark space deep freeze.
Rosetta had been programmed to touch down at a human walking pace of about 90cm (35”) per second, after a 14-hour freefall from an altitude of 19km (12 miles).
It joined long-spent robot probe Philae on the galactic wanderer’s rocky, cold surface for an eternal journey around the Sun.
Confirmation of the mission’s end came at 1119 GMT, when the spacecraft’s signal – with a 40-minute delay – disappeared from ground controllers’ computer screens.
“We have loss of signal of Rosetta,” announced a grim-faced Lodiot. “We will be listening for a signal for another 24 hours, but don’t expect any...”
Mission scientists had expected Rosetta would bounce and tumble about before settling – but the craft’s final moments will forever remain a mystery as it was instructed to switch off on first impact.
The comet chaser was never designed to land.
In its final hours, Rosetta sent home crucial last-gasp data gathered from nearer the comet than ever before, tasting the comet’s gas, dust and plasma, and taking close-up pictures of the spot that is now its icy tomb.
“It’s a bittersweet thing,” Taylor told AFP.
While scientists are looking forward to delving into Rosetta’s last-minute data, “there is something about the attachment, there’s something about that spacecraft being there. I will feel a sense of loss, surely”.
Rosetta and lander probe Philae had travelled more than 6bn kilometres over 10 years to reach 67P in August 2014.
A social media campaign and cartoon depicting the pair as intrepid space explorers, each with its “own” Twitter account, earned the mission a global following.
Yesterday the cartoon was updated with a dusty and bashed-up Rosetta lying eyes closed on the comet surface, as Earth held a placard proclaiming “Goodbye Rosetta”.
“#Rosetta, is that you?” the European Space Agency (ESA) tweeted on Philae’s behalf.
Philae was sent to the comet surface in November 2014, bouncing several times, then gathering 60 hours of on-site data which it sent home before entering standby mode.
Rosetta stuck with the comet, hoping to eyeball Philae, which it finally did in September this year.
But the spaceship started running low on energy as the comet looped out on its near seven-year orbit, further and further away from the Sun’s battery-replenishing rays.
Instead of letting Rosetta fade away, scientists opted to end the mission on a high by taking comet measurements from up close – too close to risk under usual operating conditions.
One highlight was a one-off chance to peer into mysterious pits dotting the landscape for hints as to what the comet’s interior might look like.
“Scientists are like children: they dream without limits. There is nothing better than making dreams of children become a reality,” flight operations director Andrea Accomazzo told AFP. “This is the feeling we have. For me today is mission accomplished.”
Insights gleaned from the €1.4bn ($1.5bn) project have shown that comets crashing into an early Earth may well have brought amino acids, the building blocks of life.
Comets of 67P’s type, however, certainly did not bring water, scientists have concluded.
“Rosetta has blown it all open. It’s made us have to change our ideas of what comets are, where they came from and ... how the solar system formed and how we got to where we are today,” said Taylor. “We have only just scratched the surface. We have decades of work to do. The spacecraft may end but the science will continue.”
For flight operators, the separation was more difficult.
“They (scientists) still have the data to analyse but we don’t have the spacecraft anymore,” lamented Lodiot, who had been involved in the project for 12 years.
“Of course there is a bit of sadness,” added Accomazzo, whose involvement spans nearly 20 years.
“You are going to miss it. But OK, life goes on,” he shrugged.