Within the next few weeks, NASA expects to register a historical moment with its OSIRIS-REx. The robotic spacecraft will come into contact with asteroid Bennu. The contact will only last for a few minutes. However, despite the short period, the spacecraft should collect a sample of the rocks and the dust of this particular asteroid. The sample will be studied on Earth.
The first attempt of this mission, commonly referred to as the Touch-And-Go (TAG), will take place on October 20. If the mission is a success, it will be a debut for NASA to collect rocks and dust from an asteroid is concerned.
During the samples’ collection, the spacecraft will land on the satellite at a point by the name Nightingale. This rocky area on the northern satellite of the Bennu satellite has a diameter of 16 meters, which is equivalent to 52 feet. The mission organizers chose this particular area because it has a lot of fine-grained material, and since they are also unobstructed, it makes it even better. In addition to that, its surface also has several building-sized boulders.
Upon landing on the Nightingale site, the spacecraft will collect the sample using its robotic sampling arm. While at it, the spacecraft will be parked somewhere not far from the area with large boulders.
The sample collection is expected to take between 4 and 5 hours. During that period, the spacecraft will need up to three maneuvers to reach the Bennu satellite’s surface. The first maneuver will be the orbit departure one. It will commence once the spacecraft fires its thrusters to leave its orbit, which is about 2,500 feet equivalent to 770 meters. Upon its initiation, the foldable robotic sampling arm will unfold, ready to collect the samples. The motion will be downward trajectory, and the second maneuver, Checkpoint, will only take place after the satellite has travelled for 4 hours. The expected altitude will be around 410 feet, equivalent to 125 meters. Its significant is to help the spacecraft to align itself with the asteroid and, at the same time, adjust its descending speed. Consequently, the OSIRIS-REx will start descending steeply towards Bennu.
The last maneuver will take place at an estimated altitude of 177 feet or 54 meters. The time interval between the second and the third maneuver will be approximately 11 minutes. This third maneuver will slow the descending spacecraft’s speed and ensure its path with match the rotation of the asteroids by the time Bennu and OSIRIS-REx come into contact.
As a result of the difference between the asteroid and Earth, about 207 million miles, the lag is quite long; therefore, signals between them will be taking about 18.5 minutes. That’s probably one reason why the OSIRIS-REx will leave Bennu in 2021 and arrive on Earth is late 2023. So, the samples are not expected to reach Earth until September 24, 2023.