‘End of mission’: Nasa farewells Saturn explorer Cassini as it plunges into gas giant
As the only spacecraft to ever orbit the planet, it showed us the rings and moons up close during its 20-year journey
Nasa’s Cassini spacecraft disintegrated in the skies above Saturn early on Friday in a final, fateful blaze of cosmic glory and following a remarkable 20-year journey.
Confirmation of Cassini’s demise came at about 7.55am, when radio signals from the spacecraft – its last scientific gifts to Earth – came to an abrupt halt. The radio waves went flat and Cassini fell silent.
The spacecraft actually burned up like a meteor 83 minutes earlier as it dived through Saturn’s atmosphere, becoming one with the giant gas planet it set out to explore in 1997. But it took that long for the news to arrive at Earth a billion miles away.
Watch Cassini’s grand finale video
The only spacecraft to ever orbit Saturn, Cassini showed us the planet, its rings and moons up close in all their glory. Perhaps most tantalising, ocean worlds were unveiled by Cassini and its hitchhiking companion, the Huygens lander, on the moons Enceladus and Titan, which could possibly harbour life.
Cassini snapped its “last memento photos” of the Saturn system on Thursday. Dutiful to the end, the spacecraft then sampled Saturn’s atmosphere on Friday morning as it made its final plunge.
Programme manager Earl Maize made the final announcement.
“This has been an incredible mission, an incredible spacecraft and you’re all an incredible team,” Maize said. “I’ll call this the end of mission.”
Flight controllers wearing matching purple shirts gave Cassini a standing ovation, embraced and shook hands.
More than 1,500 people, many of them past and present team members, had gathered at California’s Jet Propulsion Laboratory for what was described as both a vigil and celebration. Even more congregated at nearby California Institute of Technology, which runs the lab for Nasa.
Project scientist Linda Spilker said Cassini had been running “a marathon of scientific discovery” for 13 years at Saturn.
“So we’re here today to cheer as Cassini finishes that race,” she said.
The spacecraft tumbled out of control while plummeting at more than 122,000km/h. Project officials invited ground telescopes to look out for Cassini’s last-gasp flash, but doubted it would be spotted from a billion miles away.
This grand finale came about as Cassini’s fuel tank started getting low. Scientists wanted to prevent the spacecraft from crashing into Enceladus or Titan, and contaminating those pristine worlds.
So in April, Cassini was directed into the previously unexplored gap between Saturn’s cloud tops and the rings. Cassini entered the gap and came out again 22 times during its mission – the last time being just last week.
The leader of Cassini’s imaging team, Carolyn Porco, a visiting scholar at the University of California, Berkeley, said she was involved in the mission for so long that now “I consider it the start of life, part two”.
Cassini departed Earth in 1997 and arrived at the solar system’s second largest planet in 2004. The European Huygens landed on big moon Titan in 2005. Nothing from Earth has landed farther.
In all, Cassini collected more than 453,000 images and travelled 4.9 billion miles. It was an international endeavour, with 27 nations taking part. The final price tag was US$3.9 billion.