Nasa's Cassini spacecraft falls silent after dramatic plunge towards Saturn
Nasa’s Cassini spacecraft has met its demise as it plunged into Saturn’s atmosphere this morning where it was vaporised within minutes in a meteoric blaze.
The dramatic end of one the space agency’s most successful missions was confirmed at just before 1pm UK time, as the signal from Cassini fell silent for the first time in 13 years.
Analysis What did the Cassini mission tell us about Saturn and its moons?
Cassini revealed Saturn and its moons in stunning detail, but its observations of the moon Enceladus are potential game-changers in the hunt for life
Read moreEarl Maize, Cassini program manager, said the probe had performed “just about perfectly”. “To the very end the spacecraft did everything we asked,” he said. “We got every last second of data.”
In its final week, the spacecraft looped between the rings and the planet one last time, past Titan, Saturn’s giant moon, for a farewell fly-by, before diving into Saturn’s atmosphere at 120,000km/h (76,000mph).
As the gases began rushing over the surface of the spacecraft, the craft would have started to tumble uncontrollably, cutting the spacecraft’s radio link with the Earth. Within a minute, the aluminium body of the craft, which is around the size of a removal van, would have melted. The last bits to go would probably have been the iridium and graphite casings that contain the probe’s 72 plutonium fuel pellets.
From the Nasa control room, these turbulent last moments could only be imagined; the end was indicated 83 minutes after the actual event as the signal faltered and then fell silent.
As the confirmation came in that communication from Cassini had ceased, Maize told the control room: “This has been an incredible mission, an incredible spacecraft and you’re all an incredible team. I’m going to call this end of mission.”
The news was met with subdued applause and some scientists hugged.
Julie Webster, spacecraft operations manager, said the final sequence had gone almost exactly as planned - the signal was lost just 30 seconds later than predicted - but added that this success was bittersweet. “I no longer have a spacecraft that will keep me up at night,” she said. “After a few days, I think I’ll really miss that.”
The dramatic end to the $4bn (£3bn) mission was partly designed to rule out the possibility of Cassini contaminating the pristine environment on Saturn’s moons Titan or Enceladus, both of which feature some of the necessary conditions for life as we know it to thrive. Cassini was also able to capture the closest images yet of Saturn’s rings during its final sequence, in which it became the first manmade object to pass between Saturn and its rings.
Cassini's final moments: Nasa spacecraft sends last signals on Saturn death plunge – as it happened
After 20 years and a journey of eight billion kilometres, Cassini has fallen silent following its dive towards Saturn
Read moreDuring the coming weeks scientists will analyse the final data package, which is expected to reveal new details about the makeup of Saturn’s atmosphere and could help answer the question of how long a day is on Saturn, since the rate of rotation of the giant gaseous planet has been impossible to measure using Earth-based telescopes.
Prof John Zarnecki, president of the Royal Astronomical Society, who worked on Cassini for more than 20 years, said: “Of course I feel slightly sad. But it’s given me the most wonderful ride and it delivered my instrument to the surface of Titan where it’s still sitting! It has shown Titan to be even more wonderful than we had ever imagined – we’ve seen seas and lakes and rivers and dune fields and clouds and rain and more.”
Prof Martin Rees, Astronomer Royal, described the mission as one of the greatest scientific and engineering achievements in space exploration. “Cassini has given us a cornucopia of information about Saturn, its rings and its moons,” he said. “Moreover, it carried in its cargo bay a smaller robotic probe, Huygens, built by the European Space Agency, which achieved a ‘soft landing’ on Saturn’s giant moon Titan, revealing lakes and rivers of liquid methane on that exotic world. Close flybys of a smaller moon, Enceladus, confirmed that there was an ocean under the ice – perhaps the most likely location in our solar system for life.”
Source: https://www.theguardian.com/science/2017/sep/15/nasas-cassini-spacecraft-falls-silent-after-dramatic-plunge-towards-saturn
The dramatic end of one the space agency’s most successful missions was confirmed at just before 1pm UK time, as the signal from Cassini fell silent for the first time in 13 years.
Analysis What did the Cassini mission tell us about Saturn and its moons?
Cassini revealed Saturn and its moons in stunning detail, but its observations of the moon Enceladus are potential game-changers in the hunt for life
Read moreEarl Maize, Cassini program manager, said the probe had performed “just about perfectly”. “To the very end the spacecraft did everything we asked,” he said. “We got every last second of data.”
In its final week, the spacecraft looped between the rings and the planet one last time, past Titan, Saturn’s giant moon, for a farewell fly-by, before diving into Saturn’s atmosphere at 120,000km/h (76,000mph).
As the gases began rushing over the surface of the spacecraft, the craft would have started to tumble uncontrollably, cutting the spacecraft’s radio link with the Earth. Within a minute, the aluminium body of the craft, which is around the size of a removal van, would have melted. The last bits to go would probably have been the iridium and graphite casings that contain the probe’s 72 plutonium fuel pellets.
From the Nasa control room, these turbulent last moments could only be imagined; the end was indicated 83 minutes after the actual event as the signal faltered and then fell silent.
As the confirmation came in that communication from Cassini had ceased, Maize told the control room: “This has been an incredible mission, an incredible spacecraft and you’re all an incredible team. I’m going to call this end of mission.”
The news was met with subdued applause and some scientists hugged.
Julie Webster, spacecraft operations manager, said the final sequence had gone almost exactly as planned - the signal was lost just 30 seconds later than predicted - but added that this success was bittersweet. “I no longer have a spacecraft that will keep me up at night,” she said. “After a few days, I think I’ll really miss that.”
The dramatic end to the $4bn (£3bn) mission was partly designed to rule out the possibility of Cassini contaminating the pristine environment on Saturn’s moons Titan or Enceladus, both of which feature some of the necessary conditions for life as we know it to thrive. Cassini was also able to capture the closest images yet of Saturn’s rings during its final sequence, in which it became the first manmade object to pass between Saturn and its rings.
Cassini's final moments: Nasa spacecraft sends last signals on Saturn death plunge – as it happened
After 20 years and a journey of eight billion kilometres, Cassini has fallen silent following its dive towards Saturn
Read moreDuring the coming weeks scientists will analyse the final data package, which is expected to reveal new details about the makeup of Saturn’s atmosphere and could help answer the question of how long a day is on Saturn, since the rate of rotation of the giant gaseous planet has been impossible to measure using Earth-based telescopes.
Prof John Zarnecki, president of the Royal Astronomical Society, who worked on Cassini for more than 20 years, said: “Of course I feel slightly sad. But it’s given me the most wonderful ride and it delivered my instrument to the surface of Titan where it’s still sitting! It has shown Titan to be even more wonderful than we had ever imagined – we’ve seen seas and lakes and rivers and dune fields and clouds and rain and more.”
Prof Martin Rees, Astronomer Royal, described the mission as one of the greatest scientific and engineering achievements in space exploration. “Cassini has given us a cornucopia of information about Saturn, its rings and its moons,” he said. “Moreover, it carried in its cargo bay a smaller robotic probe, Huygens, built by the European Space Agency, which achieved a ‘soft landing’ on Saturn’s giant moon Titan, revealing lakes and rivers of liquid methane on that exotic world. Close flybys of a smaller moon, Enceladus, confirmed that there was an ocean under the ice – perhaps the most likely location in our solar system for life.”
Source: https://www.theguardian.com/science/2017/sep/15/nasas-cassini-spacecraft-falls-silent-after-dramatic-plunge-towards-saturn