The probe began its two-year trip back to Earth from the 101955 Bennu asteroid last May. It is believed to be carrying a sample of Bennu weighing up to 1kg.
But Nasa has now decided to extend its mission, which will be renamed OSIRIS-APEX (short for OSIRIS-Apophis Explorer), to study the near-Earth asteroid Apophis for 18 months. Apophis will make a close approach to Earth in 2029.
The University of Arizona will lead the mission, which will make its first manoeuvre toward Apophis 30 days after the spacecraft delivers the sample it collected from Bennu. The extension adds another $200m (£153m) to the mission cost cap.
The mission team did an exhaustive search for potential asteroid targets. The OSIRIS-REx spacecraft was built for what’s called a rendezvous mission, meaning instead of making a single flyby of an object and quickly snapping images and collecting data, it was designed to “get up close and personal with the object.” DellaGiustina said. “Our...