Nasa has selected two concepts for further study – for a robotic mission to launch in the 2020s, the fourth in its New Frontiers programme

A sample return spacecraft to a comet and a drone to fly across a moon of Saturn are the two robotic mission concepts chosen for further study by Nasa this week. Both proposals build upon previous missions performed by the European Space Agency.

The Comet Astrobiology Exploration Sample Return (Caesar) mission would revisit comet 67P/Churyumov-Gerasimenko. This is the icy body that ESA explored with its Rosetta spacecraft and Philae lander in 2014.

Comets are the leftovers of planetary formation. Caesar would bring back samples to further investigate its origin and history.

Dragonfly would explore the chemistry of Saturn’s intriguing moon Titan. It would be a drone capable of flying through Titan’s atmosphere, and would be used to explore the moon’s habitability in dozens of places across its surface. It would be following ESA’s Huygens mission, which landed in 2005 as part of Nasa’s Cassini mission. Some data from those missions suggest an alien form of hydrocarbon biology just might be possible.

The winning teams have been awarded study funds to take them through to spring 2019, when one of these missions will be selected for building. Launch will then take place in the mid 2020s.

It will be the fourth mission in Nasa’s New Frontiers programme. The first was the New Horizons spacecraft that explored Pluto in 2015. The other two are Juno, which is in orbit around Jupiter, and Osiris-Rex, which is due to arrive at asteroid Bennu next year.



