The CAESAR (Comet Astrobiology Exploration SAmple Return) mission will acquire a sample from the nucleus of comet Churyumov-Gerasimenko, returning it safely to Earth. Comets are made up of materials from ancient stars, interstellar clouds, and the birth of our solar system. The CAESAR sample will reveal how these materials contributed to the early Earth, including the origins of the Earth's oceans, and of life. Image Credit: NASA

Launch Date TBD
Launch Site TBD
Destination Comets,67P/Churyumov-Gerasimenko
Type Sample Return
Status Concept
Nation United States
Alternate Names Comet Astrobiology Exploration SAmple Return


The CAESAR (Comet Astrobiology Exploration SAmple Return) mission is a comet sample return mission concept selected in December 2017 for further development. The spacecraft would return a sample from 67P/Churyumov-Gerasimenko, a comet that was successfully explored by the European Space Agency’s Rosetta spacecraft, to determine its origin and history.


The CAESAR and Dragonfly missions will receive funding through the end of 2018 to further develop and mature their concepts. NASA plans to select one of these investigations in the spring of 2019 to continue on to subsequent mission phases.


Launch Vehicle: TBD

Spacecraft Mass: TBD

Spacecraft Instruments:


Additional Resources

NASA Invests in Concept Development for Missions to Comet, Saturn Moon Titan

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