## 1 Introduction  
The rapid development of pLEO constellations, composed of small satellites, has revolutionized communications and navigation services [1; 2; 3]. The global coverage afforded by these innovative pLEO constellations opens up unparalleled opportunities for alternative positioning, navigation, and timing (AltPNT) solutions that can reshape our technological landscape. Navigation services utilizing one-way time-of-flight with GNSS hinge upon the meticulous monitoring of stable clocks that send out ranging signals. Each satellite houses multiple highly stable microwave clocks, all integrated into a robust timekeeping system. Managing the performance of these satellite clocks and synchronizing them with laboratory-based standards is crucial for creating an accurate time scale. This synchronization allows for reliable tracking of GNSS signals from ground reference stations worldwide. Furthermore, essential corrections are made for each satellite clock to ensure alignment with the reference time scale that is distributed to users [4; 5; 6]. However, it is essential to recognize that the principles underpinning GNSS are not easily applicable to LEO spacecraft, which operate with shorter lifetimes. GNSS depends on large, heavy atomic clocks, which are continuously monitored by a global network of ground stations to enable precise positioning and timing. These ground stations also upload clock corrections to maintain user accuracy. Unfortunately, managing the onboard clocks for a LEO constellation places a substantial burden on the ground network. Effectively providing global navigation services from LEO necessitates comprehensive coordination and operational oversight. To truly tackle the challenges of achieving global coverage with dedicated networks for precise positioning, such a ground infrastructure must deploy over 100 stations worldwide and add several hundred more in specific regions to ensure optimal real-time performance. This ambitious objective demands a thorough reevaluation of the foundational elements of GNSS time scales to unlock the potential for enhanced navigation and positioning capabilities in the modern era. Recent advancements, as noted in [7], indicate that a hybrid architecture that combines the Galileo constellation of Medium Earth Orbiting (MEO) satellites with a small constellation of LEO satellites--augmented by selected optical inter-satellite links (ISLs)--has the potential to greatly diminish our dependence on terrestrial infrastructure. This innovative approach allows for direct synchronization among satellites, thereby eliminating the need for MEO satellites to carry onboard clocks. Furthermore, as demonstrated in [8], a comprehensive series of simulations used the Galileo constellation as a benchmark, progressively adding features like LEO satellites, ISLs, and synchronized clocks. The goal was to assess how these enhancements impact orbit signal-in-space errors and essential geodetic quality Earth parameters such as polar coordinates, the length of the day, and geo-center coordinates. However, a significant challenge remains: the limited supply of space-qualified clocks that meet GNSS-level performance standards. Currently, only a handful of U.S. suppliers can manufacture about five of these clocks per year. Additionally, today's GNSS-quality space clocks tend to be bulky, heavy, and power-consuming. This combination of size,weight, and power (SWaP) requirements creates obstacles when deploying smaller systems in proliferated LEO constellations. For addressing the pressing need for GNSS-quality clocks in proliferated constellations, one promising approach is to develop an ensemble of clocks onboard a single space vehicle. This vehicle could then disseminate accurate time to other satellites based on its performance and holdover capabilities. Alternatively, a constellation-wide ensemble could be formed, which distributes precise time to other assets as needed.