The OSIRIS-APEX mission, an extension of the wildly successful OSIRIS-REx mission, is set to rendezvous with Asteroid 99942 Apophis in April 2029. This mission takes full advantage of the OSIRIS-REx spacecraft, which still has plenty of fuel and is totally healthy after delivering samples from Asteroid Bennu to Earth on 24 September, 2023.

OSIRIS-APEX will closely observe Apophis as the asteroid makes a remarkably close flyby of Earth, coming within 32,000 kilometers (20,000 miles)  – closer than some Earth-orbiting satellites. The mission's primary objectives are to study how Earth's gravitational pull affects the orbit of Apophis, its spin, and surface features.

However, the mission is in peril. The proposed Presidential Budget Request for Fiscal Year 2026 budget calls for the cancellation of OSIRIS-APEX, despite its low cost and the scientific value it offers as an extended mission using an already existing and proven spacecraft.

On this episode of Talking Space, we're joined by Dr. Dani Mendoza DellaGiustina, Principal Investigator for the OSIRIS-APEX mission and Assistant Professor at the University of Arizona's Lunar and Planetary Laboratory. We'll delve into the mission's goals, the reasons given behind its potential cancellation in the 2026 NASA Budget, and the options available should the 2026 budget be approved by Congress, a budget that cancels this ambitious mission.

Guest: Dr. Dani Mendoza DellaGiustina, Assistant Professor, University of Arizona - Lunar and Planetary Laboratory. 

Host: Gene Mikulka

Additional information on the 2026 NASA Budget via NASA 

Advocacy Resources from the Planetary Society