Abstract: Designed to provide the significant capability required for human deep-space exploration, the National Aeronautics and Space Administration’s Space Launch System (SLS) also provides an exceptional opportunity for lower-cost deep-space science in the form of small-satellite (smallsat) secondary payloads. This opportunity will be leveraged beginning with the rocket’s first flight; a launch of the SLS’s Block 1 configuration, capable of delivering >26 metric tons (t) to Trans-Lunar Injection (TL…