Lunar Gateway

The Lunar Gateway, or simply Gateway, is a planned space station to be assembled in orbit around the Moon. Developed as part of NASA’s Artemis program, the Gateway is intended to serve as a communications hub, science laboratory, and habitation module for supporting both crewed and robotic lunar exploration. It is designed to be the first space station constructed beyond low Earth orbit and as a staging point for future human missions to Mars.
The project is led by NASA in collaboration with international partners, including the European Space Agency, the Japan Aerospace Exploration Agency, the Canadian Space Agency, and the Mohammed Bin Rashid Space Centre, with additional participation from commercial partners.
In July 2025, the passage of the One Big Beautiful Bill Act allocated $2.6 billion to fund the program through FY 2032.

Overview

The Gateway is expected to serve a central role in the Artemis program beginning in the latter half of the 2020s: providing docking ports and communications relays for Orion and lunar landers like Starship HLS, staging for surface missions to the lunar south polar region, and as a platform for crewed transfer. It will also be used to evaluate concepts needed for long-duration deep-space missions.
Scientific research to be studied on the Gateway are expected to include planetary science, astrophysics, Earth observation, space biology, heliophysics, and studies of human health and performance in deep-space environments.
Construction of the station's initial elements, including the Power and Propulsion Element and the Habitation and Logistics Outpost , began in the early 2020s. PPE and HALO are planned to launch together on a Falcon Heavy no earlier than 2027, with crewed assembly and first crewed visits expected to be part of Artemis IV, currently targeted for no earlier than September 2028.

Name

The station was initially announced as the Deep Space Gateway in 2017. NASA’s FY 2019 budget request renamed the station as Lunar Orbital Platform-Gateway .
In November 2019, NASA officially designated the station as Gateway. The station’s logo was inspired by the American landmark Gateway Arch in St. Louis.

History

Background

The Apollo Command and Service Module was the first crewed lunar orbiting spacecraft performing dockings and crew transfers with another spacecraft, the Apollo Lunar Module. Lunar bases, like the first Tranquility Base as well as concepts for lunar bases have been the main focus of human presence at the Moon.

Studies

An earlier NASA proposal for a cislunar station had been made public in 2012 and was dubbed the Deep Space Habitat. That proposal led to funding in 2015 under the NextSTEP program to study the requirements of deep space habitats. In February 2018, it was announced that the NextSTEP studies and other ISS partner studies would help to guide the capabilities required of the Gateway's habitation modules. The solar electric Power and Propulsion Element of the Gateway was originally a part of the now-canceled Asteroid Redirect Mission.
On 7 November 2017, NASA asked the global science community to submit concepts for scientific studies that could take advantage of the Deep Space Gateway's location in cislunar space. The Deep Space Gateway Concept Science Workshop was held in Denver, Colorado, from 27 February to 1 March 2018. This three-day conference was a workshop where 196 presentations were given for possible scientific studies that could be advanced through the use of the Gateway.
In 2018, NASA initiated the Revolutionary Aerospace Systems Concepts Academic Linkage competition for universities to develop concepts and capabilities for the Gateway. The competitors were asked to employ original engineering and analysis in one of four areas: "Gateway Uncrewed Utilization and Operations", "Gateway-Based Human Lunar Surface Access", "Gateway Logistics as a Science Platform", and "Design of a Gateway-Based Cislunar Tug". Teams of undergraduate and graduate students were asked to submit a response by 17 January 2019 addressing one of these four themes. NASA selected 20 teams to continue developing proposed concepts. Fourteen of the teams presented their projects in person in June 2019 at the RASC-AL Forum in Cocoa Beach, Florida, receiving a US$6,000 stipend to participate in the Forum. The "Lunar Exploration and Access to Polar Regions", from the University of Puerto Rico at Mayagüez, was the winning concept.
On May 2, 2018, NASA stated the International Space Exploration Coordination Group, a non-binding coordination forum comprising 14 worldwide space agencies, identified the Gateway as a critical component in expanding human presence to the Moon, Mars, and deeper into the Solar System.

International participants

On 27 September 2017, an informal joint statement on cooperation regarding the program between NASA and Russia's Roscosmos was announced. However, in October 2020 Dmitry Rogozin, director general of Roscosmos, said that the program is too "U.S.-centric" for Roscosmos to participate, and in January 2021, Roscosmos announced that it would not participate in the program.
As of January 2024, the Canadian Space Agency, the European Space Agency, Japan Aerospace Exploration Agency and Mohammed Bin Rashid Space Centre plan to participate in the Gateway project, each contributing a robotic arm, refuelling and communications hardware, habitation and research capacity and an airlock module. These international elements are intended to launch after the initial NASA PPE and HALO elements are placed into lunar orbit with some co-manifested with Artemis missions.

Power and propulsion

On 1 November 2017, NASA commissioned five studies lasting four months into affordable ways to develop the Power and Propulsion Element, leveraging private companies' plans. These studies had a combined budget of US$2.4 million. The companies performing the PPE studies were Boeing, Lockheed Martin, Orbital ATK, Sierra Nevada, and Space Systems/Loral. These awards are in addition to the ongoing set of NextSTEP-2 awards made in 2016 to study development and make ground prototypes of habitat modules that could be used on the Gateway as well as other commercial applications, so the Gateway is likely to incorporate components developed under NextSTEP as well. The PPE will use four 6 kW BHT-6000 Busek Hall-effect thrusters and three 12 kW NASA/Aerojet Rocketdyne Advanced Electric Propulsion System Hall-effect thrusters for a total engine output fractionally under 50 kW. In 2019, the contract to manufacture the PPE was awarded to Maxar Technologies. After a one-year demonstration period, NASA intended to "exercise a contract option to take over control of the spacecraft". Its expected service time is about 15 years. In late 2023, it was reported that flight qualification testing was occurring on the thrusters for the Power and Propulsion Element.

Orbit and operations

The Gateway will be deployed in a near-rectilinear halo orbit around the Moon. The eccentricity of the chosen NRHO takes the station within of the lunar north pole surface at closest approach, and as far away as over the lunar south pole, with a period of about 7 days. One of the advantages of an NRHO is the minimal amount of communications blackout with the Earth.
Traveling to and from cislunar space is intended to develop the knowledge and experience necessary to venture beyond the Moon and into deep space. The proposed NRHO would allow lunar expeditions from the Gateway to reach a low polar orbit with a Δv of 730 m/s and a half a day of transit time. Orbital station-keeping would require less than 10 m/s of Δv per year, and the orbital inclination could be shifted with a relatively small Δv expenditure, allowing access to most of the lunar surface. Spacecraft launched from Earth would perform a powered flyby of the Moon followed by a NRHO insertion burn to dock with the Gateway as it approaches the apoapsis point of its orbit. The total travel time would be 5 days; the return to Earth would be similar in terms of trip duration and Δv requirement if the spacecraft spends 11 days at the Gateway. The crewed mission duration of 21 days and is limited by the capabilities of the Orion life support and propulsion systems.
Gateway will be the first modular space station to be both human-rated, and autonomously operating most of the time in its early years, as well as being the first deep-space station, far from low Earth orbit. This will be enabled by more sophisticated executive control software than on any prior space station, which will monitor and control all systems. The high-level architecture is provided by the Robotics and Intelligence for Human Spaceflight lab at NASA and implemented at NASA facilities. The Gateway could conceivably also support in-situ resource utilization development and testing from lunar and asteroid sources, and would offer the opportunity for a gradual buildup of capabilities for more complex missions over time.

Structure

For supporting the first crewed mission to the station planned for 2028, the Gateway will begin as a minimal space station composed of only two modules: the Power and Propulsion Element and the Habitation and Logistics Outpost. Both PPE and HALO will be assembled on Earth and launched together on a Falcon Heavy rocket in 2027. They are expected to reach lunar orbit after nine to ten months. The I-Hab module, a contribution from ESA and JAXA, is to be launched on the SLS Block 1B as a co-manifested payload on the Artemis IV crewed Orion mission. All modules will be connected using the International Docking System Standard.

Planned modules

The Power and Propulsion Element started development at the Jet Propulsion Laboratory during the now canceled Asteroid Redirect Mission. The original concept was a robotic, high-performance solar electric spacecraft that would retrieve a multi-ton boulder from an asteroid and bring it to lunar orbit for study. When ARM was canceled, the solar electric propulsion was repurposed for the Gateway. The PPE will allow access to the entire lunar surface and act as a space tug for visiting craft. It will also serve as the command and communications center of the Gateway. The PPE is intended to have a launch mass of with propellant accounting for half that mass and the capability to generate 50 kW of solar electric power for its ion thrusters, which can be supplemented by chemical propulsion. In May 2019, Maxar Technologies was contracted by NASA to manufacture this module, which will also supply the station with electrical power and is based on Maxar's 1300 series satellite bus. The PPE will use Busek 6 kW Hall-effect thrusters and NASA Advanced Electric Propulsion System Hall-effect thrusters. Maxar was awarded a firm-fixed-price contract of US$375 million to build the PPE. NASA is supplying the PPE with an S-band communications system to provide a radio link with nearby vehicles and a passive docking adapter to receive the Gateway's future utilization module. NASA awarded a contract of US$331.8 million to launch PPE on a SpaceX Falcon Heavy in 2027 with the HALO module.
The Habitation and Logistics Outpost, also called the Minimal Habitation Module and formerly known as the Utilization Module, will be built by Northrop Grumman Innovation Systems. A single Falcon Heavy will launch HALO in 2027 along with the PPE module. The HALO is based directly on a Cygnus Cargo resupply module to the outside of which radial docking ports, body mounted radiators, batteries and communications antennae will be added. The HALO will be a scaled-down habitation module, yet it will feature a functional pressurized volume providing sufficient command, control and data handling capabilities, energy storage and power distribution, thermal control, communications and tracking capabilities, two axial and up to two radial docking ports, stowage volume, environmental control and life support systems to augment the Orion spacecraft and support a crew of four for at least 30 days. The overall HALO mass is expected to be 8–9 tons depending on the final internal layout configuration and launch vehicle lift capability. On 5 June 2020, Northrop Grumman Innovation Systems was awarded a contract, by NASA, of US$187 million to complete the preliminary design of HALO. On 9 July 2021, NASA signed a separate contract with Northrop for the fabrication of HALO, and for integration with the PPE being built by Maxar, for US$935 million. In July 2022, Northrop Grumman awarded Solstar a contract to supply Wi-Fi access for personnel and equipment in the HALO module. On 2 April 2024, it was announced that welding was complete on the module and that the next step was for the module to undergo a series of stress tests upon successful completion of which it would be transported to Northrop Grumman's facility in Arizona for final outfitting. In April 2025 HALO arrived in the US.
File:Team Gateway see you at the moon LR.jpg|thumb|upright=1.0|right|Thales Alenia Space Gateway manufacturing team in front of their factories in Cannes, France The European System Providing Refueling, Infrastructure and Telecommunications service module will provide additional xenon and hydrazine capacity, additional communications equipment, and an airlock for science packages. It will have a mass of approximately, and a length of. ESA has awarded two parallel design studies, one mostly led by Airbus in partnership with Comex and OHB and one led by Thales Alenia Space. The construction of the module was approved in November 2019. On 14 October 2020, Thales Alenia Space announced that they had been selected by the European Space Agency to build the ESPRIT module. In early 2021, Thales Alenia Space announced effective contract signature. The ESPRIT module will consist of two parts. The first part, called Lunar Link, will provide the communications for the Gateway. It will launch in 2027 pre-attached to the HALO module, for which Thales has separately been awarded a contract by NASA to construct its hull and micrometeoroid protection. The second part, called Lunar View, will contain the pressurized fuel tanks, docking ports and small-windowed habitation corridor and launch in 2029.
The Lunar I-HAB will be an additional habitation module built by ESA in collaboration with Japan. On 14 October 2020, Thales Alenia Space announced that they had been selected by ESA to build the I-HAB module. The module will include contributions from the other station partners, including a life support system from JAXA, avionics and software from NASA and robotics from the Canadian Space Agency. The module is slated to launch in 2028 on the Artemis IV mission as a co-manifested payload on the SLS Block 1B along with a crewed Orion spacecraft. The I-HAB would have a maximum launch mass of and provide a habitable volume of in order to increase the station's combined habitable volume to.
The Canadarm3, a pair of robotic remote manipulator arms, one large and one small, broadly similar to the Space Shuttle Canadarm and International Space Station Canadarm2, and associated dextrous manipulator. The arm is to operate autonomously; however, it is also capable of accepting control from ground stations or from astronauts aboard Gateway. The Canadarm3 is to be the contribution of the Canadian Space Agency to this international endeavor. CSA contracted MDA Space to build the arm. MDA previously built Canadarm2, while its former subsidiary, Spar Aerospace, built Canadarm.
The Crew and Science Airlock Module will be used for performing extravehicular activities outside the space station and would have the docking port for the proposed Deep Space Transport. It will be built by the UAE's Mohammed bin Rashid Space Centre, and is slated for launch around 2030.