• Deliver 4 crew to the lunar surface for 7–14 days and return them safely to Earth. • Minimum mission requires 7 CLVs & 1 SLS-B1 launch using Orion + ESM and a human lander. • Minimum mission requires 5 SpaceTugs to transfer mass between Earth and Moon orbits. • Gateway elements (PPE, HALO) are not required, but not precluded, if in low lunar orbit. • Optional cargo mission to the lunar surface adds hab, mobility devices, & experiments.