OSIRIS-REx won’t touch down on asteroid Bennu.
The spacecraft will instead give the asteroid a “high-five” with a specialized robotic arm to collect the sample.
The arm, called the Touch-And-Go Sample Acquisition Mechanism, or TAGSAM, will extend from the spacecraft when it closes in on Bennu after circling it for months. When TAGSAM makes contact, a burst of nitrogen gas will be released, stirring up loose rocks and dust.
These asteroid bits will be blown up and into a sample chamber on the end of the robotic arm. The goal is to collect a little more than 2 ounces, though the chamber can hold up to 4.4 pounds. TAGSAM has enough nitrogen to attempt to collect a sample three times.
Once a sufficient amount of asteroid rock and dust has been collected, the sample will be stored in the Sample Return Capsule — the only part of OSIRIS-REx that will return to Earth.
