According to Aviation Week, DARPA has launched its “Track at Big Distances with Track-Before-Detect” program to detect and track faint objects hundreds of thousands of miles away in cislunar space. The research agency announced on October 21 that it seeks to advance signal processing algorithms enabling commercial or quasi-commercial optical sensors to detect objects at “gigameter distances” – equivalent to 1 billion kilometers – within hours on a tactical timeline. The 15-month single-phase effort aims to reduce computational needs and power consumption while developing payload designs optimized for off-the-shelf sensors and processors. DARPA will provide more details at a November 4 proposers’ day in Arlington, Virginia, with the goal of increasing safety for cislunar commercial traffic and supporting space domain awareness. This initiative represents a significant leap in addressing the unique challenges of cislunar space monitoring.
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The Cislunar Monitoring Challenge
The cislunar region between Earth and Moon presents unprecedented tracking difficulties that existing spacecraft monitoring systems weren’t designed to handle. Unlike low Earth orbit where objects follow relatively predictable paths, cislunar trajectories are influenced by complex three-body dynamics involving Earth, Moon, and Sun gravitational forces. This creates chaotic orbital patterns that make prediction extremely challenging. The vast distances involved – up to 385,000 kilometers to the Moon’s orbit – mean objects appear incredibly faint, often below the detection thresholds of conventional sensors. Lighting conditions vary dramatically, and the sheer volume of space means traditional scanning methods are inadequate. What makes this particularly urgent is the growing commercial and government interest in lunar operations, from NASA’s Artemis program to private lunar landers, creating traffic that needs monitoring for collision avoidance and security purposes.
Revolutionary Approach to Space Tracking
The “track-before-detect” methodology represents a fundamental shift from traditional space surveillance. Conventional systems typically require detecting an object before initiating tracking, but in cislunar space, objects may be too faint for reliable initial detection. This approach uses advanced algorithms that analyze sensor data for subtle patterns indicating object presence before traditional detection thresholds are met. Essentially, it’s looking for statistical anomalies across multiple data frames that suggest something is moving through space, even when individual frames show nothing conclusive. This requires sophisticated signal processing capable of distinguishing real objects from sensor noise and background radiation across enormous distances. The computational challenge is substantial – processing must happen onboard spacecraft with limited power, which explains DARPA’s focus on algorithm efficiency.
Strategic and Commercial Implications
This technology has profound implications for both national security and commercial space operations. From a security perspective, the ability to monitor cislunar space addresses growing concerns about potential adversarial activities in this strategically important region. Both China and Russia have demonstrated interest in cislunar operations, and the U.S. needs domain awareness capabilities to protect critical assets like GPS satellites in higher orbits and future lunar infrastructure. Commercially, as companies plan lunar mining operations, space tourism, and satellite servicing in cislunar space, reliable traffic management becomes essential. The emphasis on commercial-off-the-shelf components suggests DARPA wants to enable widespread adoption beyond military applications. This could lead to a new market for cislunar monitoring services and create standards for space traffic management in this emerging domain.
Overcoming Technical Barriers
Several significant technical challenges must be overcome for this program to succeed. The signal-to-noise ratio at gigameter distances is extremely poor, requiring algorithms that can extract meaningful data from nearly imperceptible signals. Power constraints are another major hurdle – space-qualified processors must balance performance with the limited power available on most spacecraft, especially if these sensors are deployed as secondary payloads. The program’s focus on reducing computational needs suggests DARPA recognizes that current processing requirements would be prohibitive for widespread deployment. Additionally, sensor calibration and maintenance in the harsh space environment presents ongoing challenges. The 15-month timeline is aggressive, indicating this is likely an initial proof-of-concept phase rather than a complete solution.
The Road Ahead for Space Domain Awareness
Success in this DARPA program could catalyze broader changes in how we approach space situational awareness. If commercial sensors can be effectively deployed across multiple spacecraft, we could see the emergence of a distributed sensor network providing continuous cislunar monitoring. This would represent a shift from ground-based and dedicated space-based surveillance systems to a more resilient, distributed approach. The technology could also enable new capabilities like detecting stealthy satellites or monitoring activities around Lagrange points, which are becoming increasingly important for future space operations. However, the program also raises questions about data sharing, international cooperation, and how monitoring capabilities might be regulated in this new frontier. As cislunar space becomes more crowded, the need for cooperative traffic management and transparent monitoring will only grow more urgent.
