NASA and Lockheed Martin have confirmed that the OSIRIS-REx space probe has reached the asteroid Bennu. From its orbit, at a distance of about 5 kilometers (a bit more than 3 miles), it will start studying its surface creating a map over the course of about a year and a half. This will allow NASA scientists not only to get to know it better but also to choose the most suitable area to proceed with the next phase of the mission, which will consist of taking samples from Bennu’s surface to be returned to Earth.
Launched on September 8, 2016, the mission of the OSIRIS-REx space probe is one of the most ambitious in the study of asteroids together with the Japanese Hayabusa2, which is orbiting the asteroid Ryugu after reaching it at the end of June 2018. Both mission aim to bring back samples of asteroids to Earth and that’s one of the reasons why there’s an exchange of information between NASA and the Japanese space agency JAXA.
On November 14, the OSIRIS-REx space probe extended its TAGSAM (Touch-and-Go Sample Acquisition Mechanism) robotic arm, the one that will be used to collect samples from the asteroid Bennu using its 3.35 meters of length and its three joints with a mechanism to catch the samples at its end. The engineers of its manufacturer Lockheed Martin made TAGSAM perform a series of movements to verify that after more than two years in deep space everything works properly.
The asteroid Bennu – formally 101955 Bennu – was discovered in 1999 and cataloged among the Apollo asteroids, a group of NEOs (Near-Earth Objects) whose orbit crosses the Earth’s. The consequence is that these asteroids are potentially dangerous and there’s a small chance that Bennu will hit the Earth between 2175 and 2199. It’s relatively small but its impact could still cause devastation in a large area.
The most ambitious goal is to bring Bennu’s samples back to Earth to analyze materials that remained almost unaltered since the birth of the solar system. However, for a year and a half the space probe will analyze its characteristics from a distance thanks to various spectrometers that will study its composition and the possible presence of organic compounds. That will also help to improve our understanding of the solar system’s history and of its planets’ formation.
On the practical side, this mission will bring information that will be useful in various ways with possible applications to other asteroids as well. It will help to better understand Bennu’s long-term motion and therefore its potential danger. It will help to assess the potential for possible mining missions. In the next years the OSIRIS-REx space probe will have really a lot work to do!