NASA’s Cassini spacecraft will make the first of five final passes over Saturn starting Sunday evening as the mission heads toward its self-destructive “grand finale” Sept. 15.
Cassini’s closest approach puts the spacecraft between 1,010 and 1,060 miles above the gas giant’s cloud tops. The spacecraft will require the use of small rocket thrusters to maintain stability in Saturn’s dense atmosphere, similar to flybys of Saturn’s moon Titan.
“Cassini’s Titan flybys prepared us for these rapid passes through Saturn’s upper atmosphere,” Earl Maize, Cassini project manager at NASA’s Jet Propulsion Laboratory, said in a statement. “Thanks to our past experience, the team is confident that we understand how the spacecraft will behave at the atmospheric densities our models predict.”
At more than 70,000 miles per hour, a piece of sand could damage or cripple the spacecraft.
If the upper atmosphere is less dense than expected, engineers may lower the spacecraft’s altitude on the last two orbits to allow the science instruments to take closer measurements. Cassini will capture high resolution observations of Saturn’s auroras, temperature and the vortexes at the planet’s poles during the final orbits.
Cassini’s project scientist, Linda Spilker, said Cassini will have become Saturn’s first atmospheric probe by the mission’s conclusion.
“It’s long been a goal in planetary exploration to send a dedicated probe into the atmosphere of Saturn and we’re laying the groundwork for future exploration with this first foray,” Spilker said in a statement.
On Sept. 11, NASA will use Titan’s gravity to slow Cassini’s orbit around Saturn to bend the path of the spacecraft into the gas giant. Cassini’s seven science instruments will be turned on and reporting in real time up until the spacecraft breaks apart roughly three minutes after it enters the atmosphere.
Cassini launched in 1997 and arrived at Saturn seven years later.