A spacecraft flying above an asteroid Heather Roper/University of Arizona This is an artist’s illustration of the OSIRIS-REx spacecraft firing thrusters near the surface of the near-Earth asteroid Apophis. The OSIRIS-REx spacecraft will be used for the extended mission, dubbed OSIRIS-APEX, to study Apophis for 18 months after the asteroid makes its close approach to Earth on April 13, 2029.