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Landsat 4 and 5. Earlier versions consisted of standard subsystem "module" or "box" components that cwld be replad witbin a structure based on predefined form hctors. Although the primary motivation for MMS was fastedchqer integration and test, standardization of interfaces, and ease of incorpomting new subsystem technology, it lacked the technology maturity and programmatic "upgrade infrastnactm?e" needed to satisfy varied mission requirements, and Uttimately it lacked user buy-in. cwsequently, it never evolved and was phased out !Such concepts as the Rapid Spacecraft Development Of€ice (RSDO) with its regularly updated atalogue of prequalifkd busses became the preferred method for acquiring satellites. N o t w i h~n ding, over the past 30 yems since MMS inception, technology h a advanced considerably and now modularity can be extended beyond &e traditiod MMS module M box to cover levels of integration, from the chip, card, box, subsystem, to the space system and to the system-ofsystems. This paper will present the MARS architecture, cast within the historical context of MMS. Its application will be highlighted by comparing a state-of-the-art point design vs. a MARS-enabled lunar mission, as a representative robotic case design.

NASA maintains and operates a global network of Very Long Baseline Interferometry (VLBI), Satellite Laser Ranging (SLR), and Global Navigation Satellite System ground stations as part of the NASA Space Geodesy Program. The NASA Space Geodesy Network (NSGN) provides the geodetic products that support Earth observations and the related science requirements as outlined by the US National Research Council (NRC in Precise geodetic infrastructure: national requirements for a shared resource, National Academies Press, Washington, 2010. http://nap.edu/12954, Thriving on our changing planet: a decadal strategy for Earth observation from space, National Academies Press, Washington, 2018. http://nap.edu/24938). The Global Geodetic Observing System (GGOS) and the NRC have set an ambitious goal of improving the Terrestrial Reference Frame to have an accuracy of 1 mm and stability of 0.1 mm per year, an order of magnitude beyond current capabilities. NASA and its partners within GGOS are addressing this challenge by planning and implementing modern geodetic stations colocated at existing and new sites around the world. In 2013, NASA demonstrated the performance of its next-generation systems at the prototype next-generation core site at NASA's Goddard Geophysical and Astronomical Observatory in Greenbelt, Maryland. Implementation of a new broadband VLBI station in Hawaii was completed in 2016. NASA is currently implementing new VLBI and SLR stations in Texas and is planning the replacement of its other aging domestic and international legacy stations. In this article, we describe critical gaps in the current global network and discuss how the new NSGN will expand the global geodetic coverage and ultimately improve the geodetic products. We also describe the characteristics of a modern NSGN site and the capabilities of the next-generation NASA SLR and VLBI systems. Finally, we outline the plans for efficiently operating the NSGN by centralizing and automating the operations of the new geodetic stations.