Closed loop GNC Testing Trade on the Psyche Mission

The Psyche mission to the asteroid (16) Psyche was selected as the fourteenth mission in the Discovery program in January 2017. The Psyche mission will determine if (16) Psyche is the core of a larger differentiated body. During the early development of the project it was assumed that the Psyche project would have the capability to perform closed loop testing (testing with the flight hardware around a GNC physics model) during ATLO (Assembly Test & Launch Operations) on the flight vehicle; however, the original design for closing the loop was not tenable due to a Maxar/JPL Interface incompatibility, so additional options had to be explored. In this paper we will look at the rationale for performing closed loop testing on flight hardware and examine other options, including open loop scenario testing in ATLO and closed loop testbed testing and validation. We will explore previous JPL-led missions' approaches to closed loop testing and summarize the decision for how to approach closed loop testing made by the Psyche team.