Unraveling the mystery of how star stuff became us

“We’re made of star stuff. We are a way for the cosmos to know itself.”

– Carl Sagan

Comet Astrobiology Exploration SAmple Return

CAESAR is a planned proposal mission to NASA’s New Frontiers Program. It would be the farthest-reaching sample return mission in history.

The spacecraft would spend its first four and a half years in space chasing down Comet 67P with one goal in mind: collect a sample from the comet’s surface and return it to Earth in pristine condition for the most extensive study of cometary material ever done.

Mission Updates

Woman in lab coat assembling spacecraft
Honeybee Robotics, Pasadena, CA

Kathryn Luczek, engineer at Honeybee Robotics, assembles the Sample Acquisition System in a clean room. This hardware is being assembled in a clean room because it is important that internal… Read more »

Man giving thumbs up while testing NASA equipment
NASA Glenn Zero G Facility

Justin Spring, engineer at Honeybee Robotics, prepares the material used to simulate the particles expected on the surface of Comet 67P. The simulated material includes fine particles that can be… Read more »

Cats eye nebula

What is star stuff?

Nearly everything you see around you began deep inside a star.

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Churyumov Gerasimenko 67P Comet

What makes comets special?

Comets are like time capsules, preserving the molecules from the beginning of our solar system and holding evidence of the origins of life.

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Spacecraft landing with parachute

Why bring a sample back to Earth?

Scientists can learn much more with the instruments on Earth than the ones that can fit on a spacecraft.

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Woman holding homemade comet

Make your own comet with dry ice to learn about their chemistry and changing state of matter—complete with shooting jets!