VANDENBERG SPACE FORCE BASE, Calif. — Space Delta 2, the U.S Space Force’s space domain awareness and space battle management delta, supported NASA’s OSIRIS-REx mission as it returned to Earth September 24, 2023. The OSIRIS-REx mission was the first U.S. mission to collect a sample from Bennu, a near-Earth asteroid, with DEL 2 units providing critical tracking and monitoring support to ensure the safe return of the sample capsule.

“Conjunction assessment is at the very core of space domain awareness,” U.S. Space Force Lt. Col. Jonathan Smith, commander, 19th Space Defense Squadron. “Understanding where objects are and where they will be shows responsibility in the space domain, but also allows us to turn that understanding into opportunities.”

This first of its kind mission allowed DEL 2’s 19 SDS to innovate and test out new SDA capabilities. The 19 SDS tracked and screened OSIRIS-REx’s spacecraft at more than 100,000km from the Earth for conjunctions and collisions as it approached the Earth from beyond geosynchronous orbit at a speed of over 12.3km/s. These screenings identified any potential conjunctions the spacecraft bus could have with other objects in space.

“OSIRIS-REx was another opportunity to exercise our cislunar surveillance capability in a new way,” said Smith. “The lessons we learned are contributing to our overall understanding and improving how we supply space domain awareness.”

The capsule containing the asteroid sample then separated from the spacecraft bus at an altitude of 108,000 kilometers and began its descent to Earth. DEL 2’s 18th Space Defense Squadron performed deorbit procedures on the sample capsule released by the bus to predict its point of reentry in the Earth’s atmosphere. The capsule survived re-entry and landed safely in the Utah desert.

“The collaboration between Space Delta 2 and NASA was essential to the success of the OSIRIS-REx mission and is a testament to the importance of working together to ensure the safety of spaceflight,” said Col. Raj Agrawal, commander, DEL 2. “We are proud to play a role in this historic mission and to help bring the first asteroid sample back to Earth.”

Located at Peterson Space Force Base, Colorado, DEL 2 builds combat-ready forces who operationalize Space Domain Awareness to identify, characterize, and exploit opportunities and mitigate vulnerabilities in the national security space terrain. DEL 2 is one of 10 mission-oriented deltas within the U.S. Space Force.

Located at Vandenberg Space Force Base, California, the 18 SDS provides tasking to the Space Surveillance Network, a worldwide network of satellite-tracking radar sensors and optical telescopes, to track artificial objects from low earth to geosynchronous orbit. The unit tracks more than 44,900 objects in Earth’s orbit, including about 8,400 active spacecraft. It maintains the most complete satellite catalog of Earth-orbiting artificial objects on Space-Track.org, which has more than 163,000 active accounts representing 205 countries. U.S. Space Command currently has SSA Sharing Agreements with 133 commercial companies, more than 30 countries, and 7 universities.

Located at the Naval Support Facility in Dahlgren, Virginia, the 19 SDS maintains custody of artificial objects in orbit in xGEO and cislunar orbit and predicts the likelihood of on-orbit collisions.