PNT and SDA for Cislunar Applications
James Lake, Laura Duffy, and Tim Britt, Canyon Consulting, LLC
Location: Ballroom E
Date/Time: Wednesday, Jun. 5, 11:10 a.m.
NASA’s Artemis I heralds the return of US missions to the lunar environment. These missions have so far relied upon legacy communications and navigation techniques dating back to the original Apollo missions. To modernize their cislunar communications and navigation infrastructure, NASA is creating a new architecture called LunaNet and is seeking input to ensure that new US capabilities in cislunar space are accurate and secure. The architecture for LunaNet ideally works not only on the lunar surface, but everywhere in the Cislunar volume with expandability beyond.
This briefing will provide an approach to provide positioning, navigation and timing (PNT) and space domain awareness (SDA) throughout the cislunar space environment. The proposed PNT architecture is a critical first step in deploying utility services throughout Cislunar space. With PNT available, other applications such as communications and domain awareness are made possible by leveraging their accurately known positions. The PNT architecture detail is provided, including placement of transmitters, radio frequency of signals, coverage throughout the cislunar service volume, and anticipated accuracy of user PNT solutions.
For space domain awareness (SDA), we provide details for a hybrid approach. This new approach leverages the baseline PNT service we propose to accurately conduct SDA. The first part of this hybrid approach is the use of passive radio frequency (RF) monitoring which provides an initial tracking solution. This passive RF track is then used as a queue for active RADAR tracking for detailed SDA analysis. The traditional range limitation of RADAR is overcome with an innovative design concept shown in the briefing. The SDA architecture detail is provided, including placement of sensors, radio frequency characteristics, coverage throughout the cislunar service volume, and availability of service.
Critical concerns for ensuring an accurate time reference frame as well as providing time transfer are included. Relativistic issues with placement of the satellites at various Cislunar space locations are considered with possible means for maintaining both PNT and SDA accuracy. Metrics are shown illustrating the issues and means for addressing them.
Finally, overall architecture resiliency is examined. The system resiliency is evaluated using a straightforward resiliency metric with associated implications to system cost. The likely acquisition costs are modeled as a resource limiting constraint on resiliency options. The resiliency results are combined with the architecture and service volume to illustrate a capable and affordable Cislunar PNT and SDA system.