Lunar Gateway

The Lunar Gateway was a planned modular space station that would have been assembled in orbit around the Moon as part of the Artemis program. Derived from earlier concepts such as the Exploration Gateway Platform, it was developed from 2017 until 2026, when the leading space agency NASA shifted focus to developing a lunar surface base. The elements of Gateway are expected to be repurposed for other projects. The project was developed with international partners including the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA), and the Mohammed Bin Rashid Space Centre (MBRSC) of the United Arab Emirates. One of the technical drivers for Gateway was the limited propulsion capability of Orion's European Service Module used for the Artemis missions, which could not independently depart from low lunar orbit. A near-rectilinear halo orbit was selected, which reduced propulsion requirements. Gateway was intended to serve as a staging point where Orion could rendezvous with Human Landing System lunar landers, transfer crews, and support lunar surface missions. It was also planned to support communications, scientific research, and habitation for both crewed and robotic missions. Before its cancellation, it was expected to be the first space station beyond low Earth orbit and a potential staging point for future human missions to Mars. Development plans called for two initial modules, the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO). Mid-way through the effort a plan emerged to launch them together on a commercial rocket. Subsequent elements were to be launched on Space Launch System (SLS) missions as co-manifested payloads with Orion and transferred to lunar orbit.