The Cassini mission around Saturn came to an end on Friday, and obviously we’re all teary-eyed. But NASA is already looking at the possibility of going back, as part of its New Frontiers program.
There are 12 ideas being looked at, with NASA planning to whittle the list down by the end of the year. Then in summer 2019, it will pick one of the missions, spending up to $850 million on it, with a planned launch by 2025.
Three missions have already launched as part of the New Frontiers program. Those are the New Horizons spacecraft to Pluto, the Juno spacecraft to Jupiter, and the OSIRIS-REx mission that is currently on its way to an asteroid.
To protect proprietary information, NASA does not release the list of the proposed missions before the selection. Thanks to blogger Van Kane, however, who has been collecting information on the missions, we know nine of the 12 proposals for the fourth selection, and the destinations for two others. The 12th remains a mystery.
Five proposals would return to Saturn and follow-up on the work of Cassini. One of these, called SPRITE (Saturn Probe Interior and Atmosphere Explorer), would drop a probe into the atmosphere of Saturn, which would collect data for up to two hours before it was destroyed.
There are two missions each for Saturn’s moons Enceladus and Titan, both of which could be habitable. One of the former missions is the Enceladus Life Finder, which would look for life by flying through the ejected plumes of Enceladus’ ocean from its south pole. Not much is known about the other mission.
One of the two Titan proposals, meanwhile, would study Titan from orbit, looking for signs that the moon is forming complex organic molecules. The second proposal, Dragonfly, is considerably more ambitious.

“The second proposed Titan mission may be the most audacious mission that I believe I have ever seen proposed,” wrote Kane. “The proposers of the Dragonfly mission... propose a rotocraft that would repeatedly fly up to tens of kilometers between landing sites.”
Of the other known proposals, two would be missions to comets and an attempt to collect a sample. Another would land on the south pole of the Moon, while there are two proposals to land on Venus and even drill into the ground. The last known mission, meanwhile, is a possible look at the Trojan asteroids that share Jupiter’s orbit, although another mission – Lucy – has already been selected for this purpose.
Given the excitement around Cassini, and the potential for life on some of Saturn’s moons, one would think a mission to Enceladus or Titan would be a pretty high priority. Any of the missions would be exciting, though.