New Delhi: 20 years after its launch and spending 13 years orbiting Saturn, NASA's Cassini spacecraft is all set to end its probe by performing a death-plunge into Saturn's atmosphere on September 15.
Rich with scientific and technical accomplishments, Cassini has had a super successful run and is already having a powerful influence on future explorations.
One of Cassini's biggest revelations includes unveiling Enceladus – Saturn's icy moon – and the fact that it has many of the ingredients needed for life. With this, the mission has inspired a pivot to the exploration of "ocean worlds" that has been sweeping planetary science over the past decade.
But, what happens after Cassini ends the mission? How does NASA plan to carry on its legacy and how will all the data that has been collected help future missions?
According to NASA, Jupiter's moon Europa has been a prime target for future exploration since NASA's Galileo mission, in the late 1990s, found strong evidence for a salty global ocean of liquid water beneath its icy crust.
But the more recent revelation that a much smaller moon like Enceladus could also have not only liquid water, but also chemical energy that could potentially power biology, was staggering.
That said, many lessons learned during Cassini's mission are being applied to planning NASA's Europa Clipper mission, planned for launch in the 2020s.
Europa Clipper will fly by the icy ocean moon dozens of times to investigate its potential habitability, using an orbital tour design derived from the way Cassini has explored Saturn.
Furthermore, a return to Saturn is also on the cards, says NASA. In the decades following Cassini, scientists hope to return to the Saturn system to follow up on the mission's many discoveries.
Mission concepts under consideration include spacecraft to drift on the methane seas of Titan and fly through the Enceladus plume to collect and analyze samples for signs of biology.
In addition to that, NASA also has its eyes set on probing Uranus and Neptune. So far, each of these worlds has been visited by only one brief spacecraft flyby (Voyager 2, in 1986 and 1989, respectively).
Collectively, Uranus and Neptune are referred to as "ice giant" planets, because they contain large amounts of materials (like water, ammonia and methane) that form ices in the cold depths of the outer solar system.
A variety of potential mission concepts are discussed in a recently completed study, delivered to NASA in preparation for the next Decadal Survey – including orbiters, flybys and probes that would dive into Uranus' atmosphere to study its composition.
Future missions to the ice giants might explore those worlds using an approach similar to Cassini's mission.