The Benefit of Space Clocks for the Deep Space Network

Ground‐based atomic clocks have been the foundation of the Deep Space Network's (DSN's) ability to provide high‐precision tracking to deep space users for navigation and radio science since its inception in the mid‐1960s. This paper describes the development of space clocks that could aid the DSN and the solar system exploration enterprise (such as by being the basis of a Lunar or Mars navigation system—similar to ground clock's role for the DSN—and by forming an in situ timescale). The paper reviews the most promising technologies potentially available in the next few years that could be used to realize these benefits for the DSN and exploration/science in the coming decade. Specifically, advances with the Deep Space Atomic Clock (DSAC) make it the most viable technology at this time for realizing a new space clock with orders of magnitude better long‐term stability than existing space clocks. Other technologies, such as a space‐capable fully optical clock with further improvements in performance, are likely more than a decade away from a space demonstration. Thus, with investment now, a follow‐on to DSAC (that we label generically as DSAC‐FO) could be ready for demonstration and commercialization in a few short years and made available for wide‐scale use by NASA and the DoD this decade.