The Orion spacecraft as a key element in a deep space gateway

With the Orion exploration vehicle and Space Launch System (SLS) approaching operational status, NASA and the international community are developing the next generation of habitats to serve as a deep space platform that will be the first of its kind, a cislunar Deep Space Gateway (DSG). The DSG is evolvable, flexible, and modular. It would be positioned in the vicinity of the Moon and allow astronauts to demonstrate they can operate for months at a time well beyond Low Earth Orbit. Orion is the next generation human exploration spacecraft being developed by NASA. It is designed to perform deep space exploration missions, and is capable of carrying a crew of 4 astronauts on independent free-flight missions up to 21 days, limited only by consumables. Because Orion meets the strict requirements for deep space flight environments (reentry conditions, deep-space communications, safety, radiation, and life support for example) it is a key element in a DSG and is more than just a transportation system. Orion has the capability to act as the command deck of any deep space piloted vehicle. To increase affordability and reduce the complexity and number of subsystem functions the early DSG must be responsible for, the DSG can leverage these unique deep space qualifications of Orion. For example, Orion already contains sleep stations, a galley, and a toilet. Therefore, the DSG would not need those functions especially in its early stages of buildup. Orion also meets deep space radiation storm shelter requirements and therefore removes the need for that accommodation on the gateway. As a visiting vehicle, Orion also has additional capacity for CO2 and humidity removal as well as excess power capacity that could be used to operate gateway systems. Because the gateway will be crew tended (meaning crew is not present continuously) it will need basic spacecraft functionality to provide functions like power, attitude control, low rate communication, and command and data handling when astronauts are not present. In this mode of operation, the gateway operates more like an interplanetary robotic vehicle, with a high level of self-sufficiency. While astronauts are living there however, the gateway will need to meet the difficult requirements of deep space and be astronaut-safe. This paper explores in more detail the many ways in which Orion can use its advanced capabilities to augment an early DSG, thereby decreasing complexity and improving affordability.