Although the US-ROK alliance is critical for the security of the Indo-Pacific region, the close bilateral military relationship has not historically extended into outer space. Policies and regulations dating to the 1970s limited space collaboration between the United States and South Korea. However, recent policy and regulatory changes have removed some of the restraints. As the two countries seek to strengthen their alliance, they should view space as a promising avenue to fortify existing security relationships and create new commercial and civil ties. The US and South Korean space programs are undergoing expansive and ambitious changes; as such, the two countries should prioritize enhanced space collaboration. Despite the limited nature of the bilateral space partnership in the past, momentum is gaining as the United States and South Korea articulate bold visions for their goals in space and as the two countries engage in more dialogue, personnel, expertise, and information exchanges, and formal agreements for collaboration. However, these strengthening ties should not be taken for granted, nor are they without challenges. The potential strategic benefits of bilateral cooperation in space should make this area a priority for the alliance.