The NOAA Satellite Observing System Architecture (NSOSA) Study Results

NOAA has conducted a study, the NOAA Satellite Observing System Architecture (NSOSA) study, to plan for the future operational environmental satellite system that will follow GOES-R and JPSS, beginning about 2030. This is an opportunity to design a modern architecture with no pre-conceived notions regarding instruments, platforms, orbits, etc., but driven by user needs, new technology, and exploiting emerging space business models. The NSOSA study team has developed evaluated nearly 100 architecture alternatives, to include partner and commercial contributions that are likely to become available. The measurement objectives include both functional needs and strategic characteristics (e.g., resiliency, flexibility, responsiveness, sustainability). The study is being informed by the Space Platform Requirements Working Group (SPRWG), commissioned by NESDIS. The SPRWG has been charged with assessing new or existing user needs and is providing relative impacts from different candidate observing systems. The SPRWG results are serving as input to the process for new foundational (Level 0 and Level 1) requirements for the next generation of NOAA satellites that follow the GOES-R, JPSS, DSCOVR, Jason-3, and COSMIC-2 missions.

This paper will discuss the key elements to providing improved system performance as well as the challenges in balancing all mission and programmatic objectives. The study was conducted without pre-conceived notions of instrument approaches, assignment to orbits, or approaches to constellation management, will be presented. Results will describe the broader decision making process and the primary candidate architectures at various cost levels. Key study results include:

1. For most annual cost levels the most cost-effective satellite observing system architectures are derivatives of the current program of record, in that they maintain a very similar allocation of functions to orbits and generally maintain the current functions.
2. Radical alternative constellations, such as MEO or LEO swarms, are generally not cost-effective at any funding level.
3. In supporting terrestrial weather missions, adding new observational capabilities, such as Wind LIDAR, plays a larger role than large increases or performance improvements in existing collection types. Many existing collection types are operating close to their point of maximum cost-effectiveness.
4. Adding high altitude, high inclination platforms (such as Molnyia or Tundra) carry relatively high cost effectiveness and can support multiple mission areas.
5. In the space weather area the impact of maintaining an off-Earth-Sun-axis platform, such as an L5 platform, plays an outsize role.