What is it about?
The return to the Moon has begun. This lunar activity means a cislunar traffic surge is coming (Cislunar refers to the region beyond geosynchronous orbit (GEO) that is mainly in the gravitational influence of Earth and/or the Moon). Once a rare and unusual mission, cislunar, and in general, all beyond GEO (XGEO) missions are poised to become a regular part of the commercial space operational ecosystem. This uptick in activity necessitates a review of the current processes, procedures, and regulations to ensure XGEO missions can be accommodated safely. This paper specifically analyzes the launch and reentry collision avoidance (LCOLA) analysis requirements to assess their applicability and shortfalls for XGEO missions and proposes new approaches to better mitigate the risks of an orbital collision causing a lunar mission launch or reentry failure.
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Why is it important?
By law, all U.S. commercial space missions require an FAA launch and/or reentry license prior to liftoff or reentry. Due to the dense traffic in Earth orbit, part of FAA commercial launch and reentry licensing criteria is a requirement to perform a Launch Collision Avoidance (LCOLA) analysis to quantify the risk of colliding with a tracked object based on lift off at various time steps within the launch window. Each LCOLA analysis eliminates seconds from the launch window when liftoff at that time causes the risk of collision to exceed the allowable risk thresholds. LCOLA analysis covers the time the launch vehicle rises above 150 km in altitude and continues for at least three hours after liftoff. Mathematically, the same LCOLA process is used to ensure licensed reentries do not collide or conjunct with a tracked space object, and for reentry the LCOLA screening process covers the time elapsed from when the reentry burn starts until the vehicle drops below 150 km for reentry vehicles performing licensed reentries. This paper explores the implications of the current LCOLA requirements listed above and proposes adaptations that are better suited to providing collision risk mitigation for XGEO launch and reentry. The current LCOLA requirements do not translate well to lunar missions for several reasons: LCOLA treats human-occupied missions the same as other missions; the pre-launch screening timeframe is inadequate to consider the entire time period for which there is collision risk with a tracked orbital object, and finally, lunar missions are likely to cross all orbital regimes on their way to the moon during LCOLA screening; current LCOLA analyses.
Perspectives
As the world is entering a new space era, one that will see the return of humans to the Moon and the establishment of sustained presence at the Lunar South Pole, it is of utmost importance to adapt our current regulations and policies to accommodate the growth of commercial space, the increase in number of deep space missions, and the anticipated expansion of crewed spaceflights in a safe manner. The space sector is no longer restricted to NASA – it involves multiple government agencies, starting with the FAA, the private sector, and the international community. The launch and reentry licensing process needs to reflect these key changes, and by being proactive and understanding the challenges of XGEO missions early, the U.S. Government can ensure that its leadership in the space sector is maintained.
Gabrielle Hedrick
The MITRE Corporation
Read the Original
This page is a summary of: Launch and Reentry Collision Risk Mitigation in the Artemis Era, January 2024, American Institute of Aeronautics and Astronautics (AIAA),
DOI: 10.2514/6.2024-1147.
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