Exploration Gateway Platform should not be confused with Lunar Gateway.
The Exploration Gateway Platform[1] was a design concept proposed by Boeing in December 2011 to drastically reduce the cost of Moon, near Earth asteroids (NEAs), or Mars missions by using components already designed to construct a refueling depot and servicing station located at one of the Earth–Moon Lagrange points, L1 or L2.[2] The system claims its cost savings based on an ability to be reused for multiple missions such as a launch platform for deep space exploration, robotic relay station for moon rovers, telescope servicing and a deep space practice platform located outside the Earth's protective radiation belts.
The platform would be constructed at the International Space Station (ISS) for testing before being relocated to EM-L1 or EM-L2 via electric or chemical propulsion rockets.
The Platform would consist of parts left over from the ISS program. Parts under consideration were Node 4 to form the main connection point, parts from the Space Shuttle's Orbital Maneuvering System (OMS) and Orbiter External Airlock would be combined to form a utility module for maneuvering, orientation and Extra-vehicular activity (EVA), a smaller version of the Canadian Arm to help with logistic and station-keeping, TransHab and/or possible inclusion of a 'Zvezda 2' or a Bigelow Inflatable station for life support systems, crew accommodations, storage, and laboratory space. Most components would be lifted into orbit using currently available EELV or commercial launchers.[1]
A reusable lander would be positioned at the platform for Moon landings and refueled using NASA's new SLS heavy lift vehicle.[1]