The JPL-managed Cassini spacecraft, which has been orbiting Saturn since 2004, is nearing the end of its mission, but it will go out in grand style by making a series of dramatic dives between the planet and its famous rings.
Mission mangers hope to send the spacecraft through that 1,500-mile-wide gap 22 times, gathering information about the planet’s internal structure and the origin of its rings, while capturing the closest photos ever taken of the planet’s clouds and inner rings.
The first of the dives is expected to begin April 26.
“This planed conclusion for Cassini’s journey was far and away the preferred choice for the mission’s scientists,” said Linda Spilker, Cassini project scientist at Jet Propulsion Laboratory. “Cassini will make some of its most extraordinary observations at the end of its long life.”
Cassini was launched 20 years ago, and the craft is running low on fuel, leading to the decision to end the mission with the series of dives before the ship plummets to the planet’s surface on Sept. 15.
On April 22, the ship will make a final pass of Saturn’s moon Titan, a maneuver that will adjust the craft’s orbital path in preparation for its final journey through the planet-rings gap.
“Based on our best models, we expect the gap to be clear of particles large enough to damage the spacecraft,” according to Earl Maize, Cassini project manager at JPL. “But we’re also being cautious by using our large antenna as a shield on the first pass, as we determine whether it’s safe to expose the science instruments to that environment on future passes.
“Certainly there are some unknowns, but that’s one of the reasons we’re doing this kind of daring exploration at the end of the mission,” he said.
While circling the planet over the past 13 years, Cassini discovered liquid methane seas on Titan and found a global ocean with indications of hydrothermal activity on the moon Enceladus.
Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA, said information collected by Cassini in its final dives “will further our understanding of how giant planets, and planetary systems everywhere, form and evolve.”
—City News Service