NASA's Osiris-Rex set to grab a piece of asteroid Bennu: How to watch live - CNET

NASA's van-size asteroid-chaser will attempt to swipe space souvenirs from Bennu Tuesday to bring home to Earth.

Artist's conception of NASA's Osiris-Rex spacecraft collecting a sample from the asteroid Bennu.

NASA's Osiris-Rex spacecraft will briefly touch down on a large asteroid Tuesday and grab some rocks and dust from its surface to be returned to Earth for study.

The touch-and-go, or TAG, sample collection of asteroid 101955 Bennu is set to go down on Tuesday, Oct.

In recent months, rehearsals have begun ahead of the upcoming sample collection attempt, and now the team says it's ready to play TAG with Bennu.

The basic plan is that Osiris-Rex will touch down on Bennu at a rocky landing site dubbed Nightingale.

The van-size spacecraft will need to negotiate building-size boulders around the landing area to touch down on a relatively clear space that's only as large as a few parking spaces.

The descent to the surface of Bennu will take roughly four hours, about the time it takes the asteroid to make one full revolution.

After this slow approach, the actual TAG sample collection procedure remarkably lasts less than 16 seconds. .

Mission organizers initially hoped the surface of Bennu would have plenty of potential landing spots covered primarily with fine materials comparable to sand or gravel.

Immediately after collecting its sample, Osiris-Rex will fire its thrusters to back away from Bennu.

Japan's Hayabusa spacecraft successfully returned tiny grains of the asteroid 25143 Itokawa to Earth in 2010