RIP Cassini: Historic Mission Ends with Fiery Plunge into Saturn
September 17, 2017 12:10 pm
NASA received its last data transmission from the Cassini spacecraft at 4:55:46 a.m. PDT (7:55:46 a.m. EDT, 1146 GMT) on September 15, before losing contact with the probe as it hurtled into Saturn’s atmosphere. It was a fiery grand finale for the probe, which spent 13 years orbiting the ringed planet.
NASA officials expect that Cassini broke apart about 45 seconds after that final transmission, due to the intense friction and heat generated by the fall.
“I hope you’re all ... deeply proud of this amazing accomplishment,” Earl Maize, the Cassini program manager, said to the mission team after the spacecraft signal was lost. “Congratulations to you all. This has been an incredible mission, an incredible spacecraft, and you’re all an incredible team. I’m going to call this the end of mission.”
The final stream of data from Cassini was received at NASA’s Jet Propulsion Laboratory (JPL) in southern California. The spacecraft communicated with Earth via the Deep Space Network, a series of telescopes around the world that keep contact with spacecraft that fly beyond the moon. The Deep Space Network is managed from JPL.
During Cassini’s final moments, mission scientists and team members watched anxiously as data continued to come in from the spacecraft as it hurtled through Saturn’s atmosphere. The signal was lost when Cassini could no longer keep its antenna pointed at Earth, due to the intense friction created by its fall through the atmosphere.
Maize said he anticipated that the probe would completely break apart about 45 seconds later. The team members stood and applauded somberly when Maize announced end of mission.
“This is a historic moment, and I think the mood reflects that,” Morgan Cable, a research scientist at JPL, said of the event. “This is a celebration of an amazing mission and incredible legacy.”
In Cassini’s final months and days, scientists and the public alike have voiced their affection for the space probe and the incredible discoveries it made.
“[I’m] feeling the love, if I may be so corny,” Maize said when asked about the public outpouring. “It’s just very heartening. Because it’s part of what we try to do — to extend everybody out to Saturn. It’s not [just for] scientists in the ivory tower; it’s for humanity. And so for everybody to get on the ride … it is just phenomenal.”
Cassini’s descent into Saturn was intentional. The spacecraft was rapidly running out of fuel, after spending nearly 20 years in space, and NASA scientists decided to make use of the mission’s inevitable conclusion.
By crashing into Saturn, Cassini had the opportunity to see what the planet’s upper atmosphere is made of, and that’s the data that the probe sent back to Earth during its final few moments of life.
The probe took its last images of the Saturn system on September 14, and transmitted those images back to Earth the same day, ahead of its plunge.