NASA’s OSIRIS-REx, now OSIRIS-APEX, is embarking on a new mission to study asteroid Apophis when it makes a close approach to Earth in 2029. Following its successful return to Earth with a sample from the asteroid Bennu, OSIRIS-APEX is set to provide insight into solar system formation and planetary defense by observing the “S-type” asteroid Apophis.
The spacecraft’s extended journey comes after it completed a seven-year, 4 billion-mile trip to bring back a sample of asteroid Bennu. Despite the long journey, the spacecraft is still in excellent condition with a quarter of its fuel left, making it well-suited for this bonus mission to explore Apophis.
Apophis is an “S-type” asteroid composed of silicate materials and nickel-iron, providing a stark contrast to the carbon-rich Bennu. The asteroid’s close approach to Earth in 2029 is a rare event, bringing it within 20,000 miles of the planet’s surface. Scientists estimate that asteroids of Apophis’ size come this close to Earth only once every 7,500 years.
The close approach will provide OSIRIS-APEX with a unique opportunity to observe how the asteroid’s surface changes due to its interaction with Earth’s gravity. It will also give scientists an opportunity to study processes fundamental to planet formation, such as tidal forces and the accumulation of rubble pile material.
Following its arrival at Apophis in April 2029, OSIRIS-APEX will closely observe the asteroid for about 18 months, studying changes triggered by its encounter with Earth and conducting various investigations of the asteroid’s surface and chemical makeup.
NASA’s Goddard Space Flight Center is overseeing the overall mission management and systems engineering for OSIRIS-APEX. The University of Arizona, Tucson, is leading the science team and the mission’s science observation planning and data processing. The spacecraft was built by Lockheed Martin Space in Littleton, Colorado, and is responsible for flight operations. Goddard and KinetX Aerospace are handling navigation for the spacecraft. The mission also includes international collaborations with the Canadian Space Agency and the Japan Aerospace Exploration Agency. OSIRIS-APEX is the third mission in NASA’s New Frontiers Program.
The mission’s scientists are excited about the prospect of studying Apophis, and hope to make surprising discoveries as they did with Bennu. The mission represents a significant step forward in our understanding of asteroid science and planetary defense research.