Cislunar traffic risks are becoming a growing challenge as interest in the moon accelerates. Over the past two years, 12 attempts have been made to send missions to the lunar surface, with private companies contributing nearly half. With increasing lunar missions, the need for lunar mission safety and structured coordination is becoming more urgent. Although only 10 to 20 missions are projected in the coming years, the reality of collision avoidance in lunar orbit is more complex than it appears.
Cislunar space spans from geostationary orbit out to the moon, forming a region with a volume 2,000 times larger than Earth’s orbital environment. This immense area may suggest that crowding is unlikely, but mission planners consistently rely on a limited set of stable lunar orbits. This creates bottlenecks where cislunar traffic risks grow quickly, despite the vastness of the surrounding space.
Tracking spacecraft in this region is also difficult. Most government monitoring systems struggle to detect objects so far from Earth, and the moon’s glare disrupts observations. This uncertainty forces operators to maneuver their spacecraft even when the likelihood of a collision is low, because the cost of being wrong is catastrophic in the context of increasing lunar missions.
Research combining space policy and astrodynamics analyzed how operators might manage lunar mission safety without unnecessary maneuvers. The study, published in 2025 in the Journal of Spacecraft and Rockets, found that with just 50 satellites in lunar orbit, each would need to conduct about four maneuvers annually to avoid predicted collisions. Collision avoidance in lunar orbit becomes costly in fuel and can disrupt mission objectives. At the current pace of development, lunar orbit could reach this number of satellites within a decade.
Actual mission reports support the concerns. The Indian Space Research Organization revealed that its Chandrayaan-2 spacecraft required three maneuvers over four years, even when only six satellites were in lunar orbit. This demonstrates how quickly congestion can emerge, validating the concerns around cislunar traffic risks.
Monitoring cislunar space is vital not only for safety but also national security. Several nations possess anti-satellite weapons, and some experts fear that hostile technology could be placed in cislunar space to avoid detection. The U.S. Space Force has identified these security implications, acknowledging that the country currently lacks consistent cislunar space monitoring capabilities. Strengthening this capacity—referred to as cislunar space domain awareness—would support intelligence gathering and threat assessment.
Several programs are already underway. The Air Force Research Laboratory is developing Oracle, a system designed to enhance cislunar space monitoring. The first Oracle satellite is scheduled for launch in 2027 and will operate from a Lagrange point, where gravitational forces allow a spacecraft to remain stable while observing regions Earth-based sensors cannot.
Improving monitoring is only part of the solution. Space agencies and private companies must share the locations and planned trajectories of their spacecraft to reduce unnecessary maneuvers. NASA’s lunar traffic coordination program compares operator data to identify potential close approaches and maintain lunar mission safety. Combined with systems like Oracle, coordination could greatly reduce collision avoidance in lunar orbit.
Future lunar missions could also benefit from coordination before launch to prevent spacecraft from clustering in the same operational regions. The Outer Space Treaty requires nations to avoid harmful interference with others’ activities, but it does not specify enforcement mechanisms. In 2025, the United Nations Committee on the Peaceful Uses of Outer Space formed a team to examine these gaps and develop new standards for cooperation.
As global scientific, commercial, and military activity expands and NASA prepares its next human mission to the moon in 2026, nations must collaborate to maintain safe and sustainable access to the lunar environment. Increasing lunar missions demand clear rules, better monitoring, and shared responsibility to protect everyone’s long-term interests in cislunar space.