COLORADO SPRINGS — An upcoming report from the Defense Intelligence Agency (DIA) discusses international activities beyond Earth’s orbit and helps to explain the U.S. Space Force’s ongoing efforts to improve observation capabilities for cislunar space.
DIA’s updated report, “Challenges to Security in Space,” highlights a wave of space activities planned in the next five years beyond Earth orbit. Most of the activities are led by the United States, the European Space Agency and Japan.
China, India, Russia and the United Arab Emirates are constructing spacecraft for missions beyond Earth orbit.
While the missions proposed focus on scientific research, “there will eventually be some exploitation and not just exploration,” which means U.S. government agencies will need to keep tabs on cislunar space activity, Troy Shafford, senior intelligence officer for the Space and Counter-Space program at the Defense Intelligence Agency, said during an Aug. 9 virtual meeting of the Space Information Sharing and Analysis Center, or Space ISAC.
“One of the things I always harp on in any forum: Our [Space Situational Awareness] is set up on an Earth-centric reference frame,” where objects in orbit follow a repeating pattern, Shafford said. “Once you get past a certain distance, it becomes very difficult to track things because the orbits don’t repeat.”
To respond to activity beyond geosynchronous orbit, which the U.S. Air Force and Space Force call xGEO, “there are three tiers of requirements before 2030,” Shafford said. “The main one is going to be xGEO space domain awareness. After that, communications and navigation.”
Space Domain Awareness will be difficult to establish for the vast area extending from geosynchronous Earth orbit to lunar orbit. Everything is eight to 10 times farther than geosynchronous orbit from Earth, meaning ground-based telescopes would need to be extremely powerful.
In addition, many cislunar orbits are so unstable that a slight deviation in spacecraft velocity can cause a dramatic change in orbital position. For example, spacecraft maneuvering near the moon could move into geosynchronous Earth orbit without expending much propellant.
“That can allow a lot of surprises, for instance, in every Earth orbit,” Peter Garretson, a former U.S. Air Force officer and senior fellow in defense studies at the American Foreign Policy Council, a nonprofit think tank, told SpaceNews. “You can pick the inclination around Earth you want to go into.”
In recent months, some U.S. military officials have emphasized the growing importance of cislunar space. “A Primer on Cislunar Space” released in June by the Air Force Research Laboratory’s Space Vehicles Directorate explains the complexity of monitoring activity in cislunar space and the merits of various sensors to observe the cislunar region.
AFRL’s Space Vehicles Directorate also announced plans in 2020 for Cislunar Highway Patrol System, a project focused on detecting and tracking objects between geosynchronous orbit and the moon.