NASA’s OSIRIS-REx asteroid sample return mission is heading towards its target asteroid Bennu and on its journey to the asteroid, NASA recently carried out tests of the MapCam imager on board the spacecraft to detect any elusive Earth-Trojan asteroids.
While the imager didn’t spot any of these asteroids, it did manage to operate flawlessly and demonstrated that it could image objects two magnitudes dimmer than originally expected. The spacecraft’s cameras MapCam and PolyCam also successfully acquired and imaged Jupiter and several of its moons, as well as Main Belt asteroids.
The spacecraft flew through the center of Earth’s fourth Lagrangian area, which is a stable region 60 degrees in front of Earth in its orbit where scientists believe asteroids may be trapped, such as asteroid 2010 TK7 discovered by NASA’s Wide-field Infrared Survey Explorer (WISE) satellite in 2010.
OSIRIS-REx Principal Investigator Dante Lauretta of the University of Arizona, Tucson said that the search was a significant success and the mission team learned so much about this spacecraft’s capabilities and flight operations that they are not confident that they are ahead of the game for when the spacecraft get to Bennu.
The Earth Trojan survey was designed primarily as an exercise for the mission team to rehearse the hazard search the spacecraft will perform as it approaches its target asteroid Bennu. This search will allow the mission team to avoid any natural satellites that may exist around the asteroid as the spacecraft prepares to collect a sample to return to Earth in 2023 for scientific study.
The spacecraft’s MapCam imager, in particular, performed much better than expected during the exercise. Based on the camera’s design specifications, the team anticipated detecting four Main Belt asteroids. In practice, however, the camera was able to detect moving asteroids two magnitudes fainter than expected and imaged a total of 17 Main Belt asteroids. This indicates that the mission will be able to detect possible hazards around Bennu earlier and from a much greater distance that originally planned, further reducing mission risk.
Scientists are still analyzing the implications of the search’s results for the potential population of Earth-Trojan asteroids and will publish conclusions after a thorough study of mission data.