DRACO technicians working in a lab
Our Contribution

Navigating the First Planetary Defense Test Mission

The Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO) was the payload instrument on NASA’s first planetary defense mission, the Double Asteroid Redirection Test (DART), to change the course of an asteroid.

About the Instrument

Instrument Type

DRACO was the lone instrument on DART, which performed a kinetic impactor demonstration by intercepting and striking an asteroid to cause a deflection of its orbit. DRACO was the sensor that enabled the intercept. A high-resolution camera derived from the New Horizons Long Range Reconnaissance Imager, DRACO’s main jobs were to support spacecraft navigation and targeting toward the Didymos asteroid system; to measure the size and shape of the target asteroid, Didymos’ small moon, Dimorphos; and to provide detailed views of the site where DART slammed into Dimorphos at 4 miles (7 kilometers) per second.

3d rendering DRACO Instrument
A detailed, 3D rendering of the DRACO instrument, which imaged the Didymos asteroid system during the DART mission.


DRACO used an 8.2-inch (20.8-centimeter) aperture telescope and a CMOS (complementary metal–oxide–semiconductor) imaging sensor. It began to image the Didymos system about 30 days before DART hit Dimorphos. In the terminal phase, DRACO images were processed autonomously on the spacecraft to determine course corrections to make an intercept. The final DRACO images sent back to Earth provided important constraints for modeling and interpreting the results of DART’s hypervelocity impact.


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