On-Orbit Propulsion System Performance of ISS Visiting Vehicles

The International Space Station (ISS) represents the culmination of over two decades of unprecedented global human endeavors to conceive, design, build and operate a research laboratory in space. Uninterrupted human presence in space since the inception of the ISS has been made possible by an international fleet of space vehicles facilitating crew rotation, delivery of science experiments and replenishment of propellants and supplies. On-orbit propulsion systems on both ISS and Visiting Vehicles are essential to the continuous operation of the ISS. This paper compares the ISS visiting vehicle propulsion systems by providing an overview of key design drivers, operational considerations and performance characteristics. Despite their differences in design, functionality, and purpose, all visiting vehicles must adhere to a common set of interface requirements along with safety and operational requirements. This paper addresses a wide variety of methods for satisfying these requirements and mitigating credible hazards anticipated during the on-orbit life of propulsion systems, as well as the seamless integration necessary for the continued operation of the ISS.