Set a calendar alert: NASA to broadcast first asteroid redirect on Monday

If we detect an asteroid that poses a threat of colliding with Earth, NASA will broadcast its first attempt to modify the asteroid's elliptical path. Double Asteroid Redirection Test is the focus of the planetary defense effort and will target a small asteroid called Dimorphos that is close to Didymos. If DART goes according to plan, it will head on collision with Dimorphos, slowing it down. There is no way for asteroids or material released by the collision to pose a threat to Earth.

Ars will be at the mission control center in the APL for the planned collision, which will be broadcasted on NASA's YouTube channels. It may take several months before we know if the collision was a success or a failure.

We put together a background on the DART mission and planned follow-up observations to make you ready for Monday.

DART and its final approach

The DART is over 600 lbs and has no instruments. There is an experimental concentrating solar cell that occupies less space to generate the same amount of power as existing space-based hardware. The ion engine is a new evolution of NASA hardware.

The action is handled by a single camera, the Didymos Reconnaissance and Asteroid Camera for Optical navigation. Every second, DRACO and the transmission hardware can send an image to Earth. Round-trip transmissions will take over a minute as DART approaches Didymos. The final approach and targeting of the asteroid will be handled by an on-board navigation system.

DRACO can't resolve Dimorphos because it's so small, and it will stay that way until about an hour and a half before impact. According to Evan Smith, DART's deputy mission system engineer, the system will shift over to on-board navigation at about four hours before impact, and then use the larger Didymos for navigation until about 50 minutes before the crash. DART will coast into a collision at about 6 kilometers a second when the ion engine is shut off.

Dimorphos is only 120 meters across, but it will fill the view from DRACO before the collision. Nancy Chabot is a planetary scientist at the APL. This is going to be the first time we see an asteroid. The final image will resolve features that are less than 100 meters across.

The transmissions will stop if things go well.