View source for Astronomy:Lunar Gateway

{{Short description|Lunar orbital space station under development}}

{{Infobox space station
 | station               = Gateway
 | station+list          = Lunar Gateway<br/>Lunar Orbital Platform-Gateway (LOP-G)<br/>Deep Space Gateway (DSG)
 | station_image         = GATEWAY (Moon Space Station).jpg
 | station_image_caption = An illustration of the Gateway's Power and Propulsion Element (PPE) and Habitation and Logistics Outpost (HALO) in orbit around the Moon in 2025
 | station_image_size    = 300px

| COSPAR_ID             = 
 | SATCAT                = 
 | sign                  =

| crew                  = Max 4 (planned)
 | launch                = November 2025 (planned)<ref name="nasa-20210709">{{cite web|url=https://www.nasa.gov/gateway/overview |title=NASA, Gateway Overview |work=[[Organization:NASA|NASA]] |date=9 July 2021 |access-date=9 July 2021}}</ref>
 | carrier_rocket        = [[Engineering:Falcon Heavy|Falcon Heavy]]<br>[[Astronomy:Space Launch System|SLS Block 1B]]
 | launch_pad            = [[Astronomy:Kennedy Space Center Launch Complex 39|Kennedy Space Center Launch Complex 39]]
* [[Astronomy:Kennedy Space Center Launch Complex 39A|LC-39A]]
* [[Astronomy:Kennedy Space Center Launch Complex 39B|LC-39B]]
 | reentry               =

| status                = In development
 | mass                  = 
 | length                = 
 | width                 = 
 | height                = 
 | diameter              = 
 | volume                = ≥{{cvt|125|m3}} (planned)<ref name=nsf-20180911/>
 | pressure              =

| orbit_reference       = 
 | orbit_regime          = 
 | perigee               = {{cvt|3000|km}}<ref name='NRHO 2019'/>
 | apogee                = {{cvt|70000|km}}
 | inclination           = Polar [[Astronomy:Near-rectilinear halo orbit|near-rectilinear halo orbit]] (NRHO)
 | period                = ≈7 days
 | apsis                 = selene

| in_orbit              = 
 | occupied              = 
 | orbits                = 
 | distance              =

| insignia              = NASA Artemis Gateway logo.png
 | insignia_caption      = 
 | insignia_size         = 200px

| configuration_image   = Gateway-infographic-11.16.22.png
| configuration_size    = 300px
| configuration_caption = Configuration as of 16 November 2022
}}
{{United States space program sidebar}}

The '''Lunar Gateway''', or simply '''Gateway''', is the first planned extraterrestrial space station. It will be placed in [[Astronomy:Lunar orbit|lunar orbit]] and is intended to serve as a [[Physics:Solar panels on spacecraft|solar-powered]] communication hub, science laboratory, and short-term habitation module for government-agency [[Astronaut|astronaut]]s, as well as a holding area for [[Astronomy:Lunar rover|rovers]] and other robots. It is a multinational collaborative project involving four of the [[Astronomy:International Space Station|International Space Station]] partner agencies — [[Organization:NASA|NASA]], [[Organization:European Space Agency|European Space Agency]] (ESA), Japan Aerospace Exploration Agency (JAXA), and the [[Organization:Canadian Space Agency|Canadian Space Agency]] (CSA) — as well as the Mohammed Bin Rashid Space Centre (MBRSC), which will provide the Crew and Science Airlock module for the Lunar Gateway.<ref name="sn-20240107" /> The Lunar Gateway is planned to be both the first space station beyond low Earth orbit and the first space station to orbit the Moon.<ref name="NASABUDGET2022">{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/fy2022_budget_summary.pdf |title=FY 2022: NASA Budget Request|publisher=NASA|date=28 May 2021|access-date=1 June 2021}} {{PD-notice}}</ref><ref name="Jackson20180911">{{cite web|title=Competition Seeks University Concepts for Gateway and Deep Space Exploration Capabilities|url=https://www.nasa.gov/feature/competition-seeks-university-concepts-for-gateway-and-deep-space-exploration-capabilities|last1=Jackson|first1=Shanessa|website=nasa.gov |publisher=NASA|date=11 September 2018|access-date=19 September 2018|archive-date=17 June 2019|archive-url=https://web.archive.org/web/20190617064456/https://www.nasa.gov/feature/competition-seeks-university-concepts-for-gateway-and-deep-space-exploration-capabilities/|url-status=live}} {{PD-notice}}</ref>

Formerly known as the '''Deep Space Gateway''' ('''DSG'''), the station was renamed '''Lunar Orbital Platform-Gateway''' ('''LOP-G''') in NASA's 2018 proposal for the 2019 United States federal budget.<ref>{{cite web|title=Some snark (and details!) about NASA's proposed lunar space station|url=http://www.planetary.org/blogs/jason-davis/2018/20180226-lop-g-snark-details.html|last1=Davis|first1=Jason|publisher=The Planetary Society|access-date=February 26, 2018|archive-url=https://web.archive.org/web/20180226175759/http://www.planetary.org/blogs/jason-davis/2018/20180226-lop-g-snark-details.html|archive-date=February 26, 2018|date=February 26, 2018}}</ref><ref>{{cite web|url=https://www.theguardian.com/science/2018/feb/12/trump-nasa-budget-moon-flying-cars-plans|title=Trump's Nasa budget: flying 'Jetson cars' and a return to the Moon|last=Yuhas|first=Alan|date=2018-02-12|newspaper=The Guardian|access-date=2018-02-25|archive-date=18 July 2019|archive-url=https://web.archive.org/web/20190718011316/https://www.theguardian.com/science/2018/feb/12/trump-nasa-budget-moon-flying-cars-plans|url-status=live}}</ref> When the NASA budget was signed into law on February 15, 2019,<ref name="sn20190217">{{cite news|title=Final fiscal year 2019 budget bill secures $21.5 billion for NASA|author=Jeff Foust|date=February 17, 2019
|url=https://spacenews.com/final-fiscal-year-2019-budget-bill-secures-21-5-billion-for-nasa/|publisher=Space News
|access-date=April 8, 2023}}</ref> US$450 million had been committed by Congress to preliminary studies.<ref name="sn20190217"/><ref>{{cite web|url=http://www.planetary.org/blogs/casey-dreier/2019/0215-fy2019-nasa-gets-its-best-budget-in-decades.html |title=NASA just got its best budget in a decade|website=planetary.org|access-date=27 February 2019|archive-date=16 February 2019|archive-url=https://web.archive.org/web/20190216012055/http://www.planetary.org/blogs/casey-dreier/2019/0215-fy2019-nasa-gets-its-best-budget-in-decades.html|url-status=dead}}</ref>

The science disciplines to be studied on the Gateway are expected to include [[Astronomy:Planetary science|planetary science]], [[Physics:Astrophysics|astrophysics]], [[Earth:Earth observation|Earth observation]], [[Physics:Heliophysics|heliophysics]], [[Astronomy:Astrobiology|fundamental space biology]], and human health and performance.<ref name="Mahoney-20180824">{{cite web|last1=Mahoney|first1=Erin|title=NASA Seeks Ideas for Scientific Activities Near the Moon|url=https://www.nasa.gov/feature/nasa-seeks-ideas-for-scientific-activities-near-the-moon|website=nasa.gov|publisher=NASA|date=24 August 2018|access-date=19 September 2018|archive-date=9 June 2019|archive-url=https://web.archive.org/web/20190609230044/https://www.nasa.gov/feature/nasa-seeks-ideas-for-scientific-activities-near-the-moon/|url-status=live}} {{PD-notice}}</ref> Construction is planned to take place in the 2020s.<ref name="Gateway_20170328"/><ref name="roscosmos20170929">{{cite web|title=РОСКОСМОС - NASA СОВМЕСТНЫЕ ИССЛЕДОВАНИЯ ДАЛЬНЕГО КОСМОСА (ROSCOSMOS - NASA JOINT RESEARCH OF FAR COSMOS) |url=https://www.roscosmos.ru/24136|access-date=September 29, 2017|archive-date=10 September 2019|archive-url=https://web.archive.org/web/20190910083456/https://www.roscosmos.ru/24136/|url-status=dead}}</ref><ref name="Weitering 2017">{{cite news|last=Weitering |first=Hanneke|url=https://www.space.com/38287-nasa-russia-deep-space-gateway-partnership.html|title=NASA and Russia Partner Up for Crewed Deep-Space Missions|publisher=Space.com|date=27 September 2017|access-date=5 November 2017|archive-date=10 September 2019|archive-url=https://web.archive.org/web/20190910194351/https://www.space.com/38287-nasa-russia-deep-space-gateway-partnership.html|url-status=dead}}</ref> The International Space Exploration Coordination Group (ISECG), which is composed of 14 space agencies including NASA, has concluded that Gateway systems will be critical in expanding human presence to the [[Astronomy:Moon|Moon]], to [[Astronomy:Mars|Mars]], and deeper into the [[Astronomy:Solar System|Solar System]].<ref>{{cite web|author1=NASA|title=Gateway Memorandum for the Record |url=https://www.nasa.gov/sites/default/files/atoms/files/gateway_domestic_and_international_benefits-memo.pdf|website=nasa.gov|publisher=NASA|date=2 May 2018|access-date=19 September 2018|archive-date=25 July 2019|archive-url=https://web.archive.org/web/20190725100820/https://www.nasa.gov/sites/default/files/atoms/files/gateway_domestic_and_international_benefits-memo.pdf|url-status=live}} {{PD-notice}}</ref>

The project is expected to play a major role in NASA's [[Astronomy:Artemis program|Artemis program]], after 2024. While the project is led by NASA, the Gateway is meant to be developed, serviced, and utilized in collaboration with the [[Organization:Canadian Space Agency|CSA]], ESA, [[Organization:JAXA|JAXA]], and commercial partners. It will serve as the staging point for both robotic and crewed exploration of the [[Astronomy:Lunar south pole|lunar south pole]] and is the proposed staging point for NASA's [[Astronomy:Deep Space Transport|Deep Space Transport]] concept for transport to Mars.<ref>{{cite web|title=NASA finally sets goals, missions for SLS – eyes multi-step plan to Mars|url=https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/ |last=Gebhardt|first=Chris|website=nasaspaceflight.com|publisher=NASASpaceflight|date=6 April 2017|access-date=19 September 2018|archive-date=21 August 2017|archive-url=https://web.archive.org/web/20170821221210/https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/|url-status=live}}</ref><ref name="Gateway_20170328">{{cite web|last1=Kathryn Hambleton|title=Deep Space Gateway to Open OpportunitiesArtemis for Distant Destinations|website=nasa.gov|date=28 March 2017|url=https://www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations |publisher=NASA|access-date=April 5, 2017|archive-date=27 September 2017|archive-url=https://web.archive.org/web/20170927164237/https://www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations/|url-status=live}} {{PD-notice}}</ref><ref name="NASA_March_2017">{{cite web|title=Cislunar Habitation and Environmental Control and Life Support System |url=https://www.nasa.gov/sites/default/files/atoms/files/20170329-nacheoc-crusan-gatens-hab-eclss-v5b.pdf|last1=Robyn Gatens|first1=Jason Crusan|website=nasa.gov|publisher=NASA|access-date=March 31, 2017}} {{PD-notice}}</ref>

== 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 lander. Lunar bases, like the first [[Astronomy:Tranquility Base|Tranquility Base]] as well as concepts for lunar bases have been the main focus of human presence at the Moon.

=== Studies ===
[[File:ISS-Derived Deep Space Habitat with CPS.jpg|thumb|upright=1.0|left|2012 concept for the Deep Space Habitat, consisting of a cryogenic propulsion stage, an ISS-derived habitat module, and a MPLM]]

An earlier NASA proposal for a cislunar station had been made public in 2012 and was dubbed the [[Astronomy:Deep Space Habitat|Deep Space Habitat]]. That proposal led to funding in 2015 under the NextSTEP program to study the requirements of deep space habitats.<ref>{{cite news|last1=Doug Messier on|title=A Closer Look at NextSTEP-2 Deep Space Habitat Concepts|url=http://www.parabolicarc.com/2016/08/11/deep-space-habitat-concepts |publisher=Parabolic Arc|date=August 11, 2016|access-date=19 September 2018|archive-date=16 September 2018|archive-url=https://web.archive.org/web/20180916065822/http://www.parabolicarc.com/2016/08/11/deep-space-habitat-concepts/|url-status=dead}}</ref> 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.<ref>{{cite web|last1=Warner|first1=Cheryl|title=NASA's Lunar Outpost will Extend Human Presence in Deep Space|url=https://www.nasa.gov/feature/nasa-s-lunar-outpost-will-extend-human-presence-in-deep-space|website=nasa.gov|publisher=NASA|date=2 May 2018|access-date=19 September 2018|archive-date=25 August 2018|archive-url=https://web.archive.org/web/20180825033038/https://www.nasa.gov/feature/nasa-s-lunar-outpost-will-extend-human-presence-in-deep-space/|url-status=live}} {{PD-notice}}</ref> The solar electric Power and Propulsion Element (PPE) of the Gateway was originally a part of the now-canceled [[Astronomy:Asteroid Redirect Mission|Asteroid Redirect Mission]].<ref>[https://www.space.com/37619-nasa-deep-space-gateway-module-outreach.html NASA Seeks Information on Developing Deep Space Gateway Module] {{Webarchive |url=https://web.archive.org/web/20171107025806/https://www.space.com/37619-nasa-deep-space-gateway-module-outreach.html|date=7 November 2017}} Jeff Foust, ''Space.com'' 29 July 2017</ref><ref name='Nov 3'/> 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.<ref name="Mahoney-20180824"/> 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.<ref>{{cite web|title=Deep Space 2018 Program |url=https://www.hou.usra.edu/meetings/deepspace2018/program.pdf|website=Lunar and Planetary Institute|publisher=Universities Space Research Association|access-date=27 January 2023}}</ref>

In 2018, NASA initiated the Revolutionary Aerospace Systems Concepts Academic Linkage (RASC-AL) 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.<ref name="Jackson20180911"/> The "Lunar Exploration and Access to Polar Regions" from the [[Organization:University of Puerto Rico at Mayagüez|University of Puerto Rico at Mayagüez]] was the winning concept.<ref>{{cite web|url=https://www.nasa.gov/feature/students-blaze-new-trails-in-nasa-space-exploration-design-competition|title=Students Blaze New Trails in NASA Space Exploration Design Competition|date=21 June 2019|publisher=NASA|access-date=5 July 2019}} {{PD-notice}}</ref>

NASA unveiled the name of the lunar-orbit space station in November 2019, and the Gateway with its name and logo associated with the American frontier symbol of the St. Louis Gateway Arch.<ref name=sdc20190918>{{cite news |url=https://www.space.com/nasa-lunar-gateway-moon-station-logo.html |title=NASA Reveals New Gateway Logo for Artemis Lunar Orbit Way Station |author=Robert Z. Pearlman |work=space.com |date=September 18, 2019 |access-date=28 June 2020 |archive-date=28 June 2020|archive-url=https://web.archive.org/web/20200628112732/https://www.space.com/nasa-lunar-gateway-moon-station-logo.html|url-status=live}}</ref>

=== International participants ===
On 27 September 2017, an informal joint statement on cooperation regarding the program between NASA and Russia's [[Company:Roscosmos|Roscosmos]] was announced.<ref name="Weitering 2017"/> However, in October 2020 Dmitry Rogozin, director general of Roscosmos, said that the program is too “U.S.-centric” for Roscosmos to participate in,<ref>{{cite web|url=https://spacenews.com/russia-skeptical-about-participating-in-lunar-gateway/|title=Russia skeptical about participating in lunar Gateway|publisher=SPACENEWS|date=12 October 2020|access-date=25 January 2021}}</ref> and in January 2021, Roscosmos announced that it would not participate in the program.<ref>{{cite web|url=https://www.interfax.ru/russia/746690|title="Роскосмос" подтвердил выход из лунного проекта Gateway|agency=Interfax|date=25 January 2021|access-date=25 January 2021}}</ref>

As of January 2024, the [[Organization:Canadian Space Agency|Canadian Space Agency]] (CSA), the [[Organization:European Space Agency|European Space Agency]] (ESA), [[Organization:JAXA|Japan Aerospace Exploration Agency]] (JAXA) and Mohammed Bin Rashid Space Centre (MBRSC) all plan to participate in the Gateway project, contributing a robotic arm called Canadarm3 (CSA), 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 [[Astronomy:Lunar orbit|lunar orbit]].<ref name="sfn20200506">{{Cite web |last=Clark |first=Stephen |date=6 May 2020 |title=NASA plans to launch first two Gateway elements on same rocket – Spaceflight Now |url=https://spaceflightnow.com/2020/05/06/nasa-plans-to-launch-first-two-gateway-elements-on-same-rocket/ |access-date=25 January 2023 |website=Space Flight Now |language=en-US}}</ref>

=== Power and propulsion ===
[[File:Gateway - PPE and HALO 001.jpg|thumb|Gateway - Power and Propulsion Element]]
On 1 November 2017, NASA commissioned five studies lasting four months into affordable ways to develop the Power and Propulsion Element (PPE), leveraging private companies' plans. These studies had a combined budget of US$2.4 million. The companies performing the PPE studies were [[Company:Boeing|Boeing]], [[Company:Lockheed Martin|Lockheed Martin]], Orbital ATK, Sierra Nevada and Space Systems/Loral.<ref name="NASA_PPE_studies">{{cite web|last1=Jimi Russell|title=NASA Selects Studies for Gateway Power and Propulsion Element|url=https://www.nasa.gov/press-release/nasa-selects-studies-for-gateway-power-and-propulsion-element|website=nasa.gov|date=November 2017|publisher=NASA|access-date=2 November 2017|archive-date=12 January 2018|archive-url=https://web.archive.org/web/20180112203046/https://www.nasa.gov/press-release/nasa-selects-studies-for-gateway-power-and-propulsion-element/|url-status=live}} {{PD-notice}}</ref><ref name='Nov 3'/> These awards are in addition to the ongoing set of [[Astronomy:Next Space Technologies for Exploration Partnerships|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,<ref name="NASA_March_2017"/> so the Gateway is likely to incorporate components developed under NextSTEP as well.<ref name='Nov 3'/><ref name="Ground_Prototypes20070728">{{cite web|last1=Erin Mahoney|title=NextSTEP Partners Develop Ground Prototypes to Expand our Knowledge of Deep Space Habitats|url=https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes|website=nasa.gov|date=9 August 2016|publisher=NASA|access-date=6 November 2017|archive-date=10 April 2017|archive-url=https://web.archive.org/web/20170410051227/https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes/|url-status=live}} {{PD-notice}}</ref> The PPE will use four 6&nbsp;kW BHT-6000 [[Company:Busek|Busek]] [[Physics:Hall-effect thruster|Hall-effect thruster]]s<ref name="PPE_Maxar" /><ref name=":3" /><ref name=":4">{{Cite press release|title=Maxar and Busek Thruster System for NASA Lunar Gateway Passes Critical Milestone|url=https://www.prnewswire.com/news-releases/maxar-and-busek-thruster-system-for-nasa-lunar-gateway-passes-critical-milestone-301250199.html|access-date=2021-04-28|website=www.prnewswire.com|language=en}}</ref> and two 12.5&nbsp;kW [[Organization:NASA|NASA]]/[[Company:Aerojet Rocketdyne|Aerojet Rocketdyne]] [[Astronomy:Advanced Electric Propulsion System|Advanced Electric Propulsion System]] (AEPS) Hall-effect thrusters for a total engine output fractionally under 50&nbsp;kW.<ref>{{Cite web|url=https://newatlas.com/space/advanced-electric-propulsion-system-aeps-full-power-test/|title=Advanced Electric Propulsion System passes full-power test milestone|date=15 November 2019|website=New Atlas}}</ref> In 2019, the contract to manufacture the PPE was awarded to [[Company:Maxar Technologies|Maxar Technologies]].<ref name="Maxar">{{cite press release|url=https://www.nasa.gov/press-release/nasa-awards-artemis-contract-for-lunar-gateway-power-propulsion|title=NASA Awards Artemis Contract for Lunar Gateway Power, Propulsion|publisher=NASA|date=23 May 2019|access-date=11 December 2019|archive-date=20 September 2019|archive-url=https://web.archive.org/web/20190920171731/https://www.nasa.gov/press-release/nasa-awards-artemis-contract-for-lunar-gateway-power-propulsion/|url-status=live}} {{PD-notice}}</ref> After a one-year demonstration period, NASA would then "exercise a contract option to take over control of the spacecraft".<ref>[https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/ NASA updates Lunar Gateway plans] {{Webarchive |url=https://web.archive.org/web/20190806063256/https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/|date=6 August 2019}} Philip Sloss, ''NASASpaceFlight.com'', 11 September 2018</ref> Its expected service time is about 15 years.<ref name='Crusan Dec2018'>[https://www.nasa.gov/sites/default/files/atoms/files/20181206-crusan-gateway-reduced-v4.pdf Gateway Update] {{Webarchive |url=https://web.archive.org/web/20200803144944/https://www.nasa.gov/sites/default/files/atoms/files/20181206-crusan-gateway-reduced-v4.pdf|date=3 August 2020}} NASA Advisory Council, Human Exploration and Operations Committee, Jason Crusan, 7 December 2018 {{PD-notice}}</ref>

== Orbit and operations ==
[[File:Near Rectilinear Halo Orbit (NRHO).png|thumb|Near-rectilinear halo orbit (NRHO) in cislunar space, as ilustrated by an A.I. Solutions, Inc. using the [[Software:FreeFlyer|FreeFlyer]] software]]
[[File:Lunar Gateway Orbit 7days Earth-Moon fixed.png|thumb|Lunar Gateway orbit. Trajectory plot over seven days with the view fixed on Moon and Earth.]]
[[File:Lunar Gateway orbit animation.webm|thumb|Lunar Gateway orbit animation. View fixed on Moon and Earth.]]
[[File:Lunar Gateway orbit animation moon north.webm|thumb|Lunar Gateway orbit animation. View from above the lunar north pole with Earth fixed below the frame bottom.]]

The Gateway is planned to be deployed in a [[Astronomy:Highly elliptical orbit|highly elliptical]] seven-day [[Astronomy:Near-rectilinear halo orbit|near-rectilinear halo orbit]] (NRHO) around the Moon, which would bring the station within {{cvt|1500|km}} over the [[Astronomy:Lunar north pole|lunar north pole]] surface at closest approach and as far away as {{cvt|70000|km}} over the [[Astronomy:Lunar south pole|lunar south pole]].<ref name='NRHO 2019'>[https://phys.org/news/2019-07-angelic-halo-orbit-chosen-humankind.html Angelic halo orbit chosen for humankind's first lunar outpost.] {{Webarchive|url=https://web.archive.org/web/20190811175615/https://phys.org/news/2019-07-angelic-halo-orbit-chosen-humankind.html|date=11 August 2019}} European Space Agency, Published by ''PhysOrg'', 19 July 2019</ref><ref>[https://newatlas.com/orbit-halo-gateway/60657/ Halo orbit selected for Gateway space station.] {{Webarchive |url=https://web.archive.org/web/20190811175613/https://newatlas.com/orbit-halo-gateway/60657/|date=11 August 2019}} David Szondy, ''New Atlas'' 18 July 2019</ref><ref name=sn20190916>{{cite news |url=https://spacenews.com/nasa-cubesat-to-test-lunar-gateway-orbit/|title=NASA cubesat to test lunar Gateway orbit|last=Foust|first=Jeff|publisher=SpaceNews|date=16 September 2019|access-date=15 June 2020}}</ref> Traveling to and from cislunar space (lunar orbit) 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 [[Astronomy:Polar orbit|polar orbit]] with a [[Astronomy:Delta-v|Δ''v'']] of 730&nbsp;m/s and a half a day of transit time. [[Astronomy:Orbital station-keeping|Orbital station-keeping]] would require less than 10&nbsp;m/s of Δ''v'' per year, and the [[Astronomy:Orbital inclination|orbital inclination]] could be shifted with a relatively small Δ''v'' expenditure, allowing access to most of the lunar surface. Spacecraft launched from Earth would perform a powered flyby of the Moon {{nowrap|(Δ''v'' ≈ 180&nbsp;m/s)}} followed by a {{nowrap|Δ''v'' ≈ 240&nbsp;m/s}} NRHO insertion burn to dock with the Gateway as it approaches the [[Astronomy:Apsis|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 Δ''v'' requirement if the spacecraft spends 11 days at the Gateway. The crewed mission duration of 21 days and {{nowrap|Δ''v'' ≈ 840&nbsp;m/s}} is limited by the capabilities of the Orion life support and propulsion systems.<ref>{{cite web|last1=Whitley|first1=Ryan|last2=Martinez|first2=Roland|title=Options for Staging Orbits in Cis-Lunar Space |url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf|website=nasa.gov|publisher=NASA|date=21 October 2015|access-date=19 September 2018|archive-date=30 July 2019|archive-url=https://web.archive.org/web/20190730111818/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf|url-status=live}} {{PD-notice}}</ref>

One of the advantages of an NRHO is the minimal amount of communications blackout with the [[Astronomy:Earth|Earth]].

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 [[Astronomy:Low Earth orbit|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 (ISRU) development and testing from lunar and [[Astronomy:Asteroid mining|asteroid]] sources,<ref>[https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180002054.pdf NASA.gov] {{Webarchive |url=https://web.archive.org/web/20180731035911/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180002054.pdf|date=31 July 2018}} Research Possibilities Beyond Deep Space Gateway] David Smitherman, Debra Needham, Ruthan Lewis, NASA, February 28, 2018 {{PD-notice}}</ref> and would offer the opportunity for a gradual buildup of capabilities for more complex missions over time.<ref name="Free 2017">[https://www.nasa.gov/sites/default/files/atoms/files/march_2017_nac_charts_architecturejmf_rev_3_tagged.pdf NASA.gov] {{Webarchive |url=https://web.archive.org/web/20200102091140/https://www.nasa.gov/sites/default/files/atoms/files/march_2017_nac_charts_architecturejmf_rev_3_tagged.pdf|date=2 January 2020}} Human Exploration and Operations Mission Directorate - Architecture Status], Jim Free, NASA, 28 March 2017 {{PD-notice}}</ref>

== Structure ==
[[File:Full view of Gateway (4k 0).jpg|thumb|right|Full proposed Lunar Gateway]]
[[File:LOP-G interior with Astronauts.jpg|thumb|upright=1.0|right|Four astronauts inside of the Gateway mock-up module at the [[Organization:Space Station Processing Facility|Space Station Processing Facility]] in the Kennedy Space Center, Florida]]
[[File:LOP-G_module_training_mock-up_module_group_photo.jpg|thumb|upright=1.0|right|NASA and Lockheed Martin employees group photo with one of the Gateway modules training mock-up inside the [[Organization:Space Station Processing Facility|SSPF]]]]

For supporting the first crewed mission to the station ([[Astronomy:Artemis 3|Artemis 3]]) planned for 2025, the Gateway will be a minimalistic mini-space station composed of only two modules: the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO).<ref name='SN 23July2019'/><ref>[https://www.space.com/nasa-lunar-gateway-start-small.html NASA's Grand Plan for a Lunar Gateway Is to Start Small.] {{Webarchive|url=https://web.archive.org/web/20191023024119/https://www.space.com/nasa-lunar-gateway-start-small.html|date=23 October 2019}} Mike Wall, ''Space.com'' - 24 May 2019</ref> Both PPE and HALO will be assembled on Earth and launched together on a [[Engineering:Falcon Heavy|Falcon Heavy]] in November 2025,<ref name="nasa-20210709" /> and they are expected to reach lunar orbit after nine to ten months.<ref>{{cite web|last1=Foust|first1=Jeff|title=NASA refines plans for launching Gateway and other Artemis elements|url=https://spacenews.com/nasa-refines-plans-for-launching-gateway-and-other-artemis-elements/|website=spacenews.com|publisher=SpaceNews|access-date=18 May 2020|date=14 May 2020|archive-date=16 May 2020|archive-url=https://archive.today/20200516065402/https://spacenews.com/nasa-refines-plans-for-launching-gateway-and-other-artemis-elements/|url-status=live}}</ref>
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 4 crewed Orion mission.<ref name="fy2022_request">{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/fy2022_congressional_justification_nasa_budget_request.pdf|quote= Delivery of I-Hab to the Gateway will be via the SLS Block 1B launch vehicle with Orion providing orbital insertion and docking. |page=PDF page 97, in-text page DEXP-67 |title=NASA FY 2022 Budget Estimates}}</ref> All modules will be connected using the [[Engineering:International Docking System Standard|International Docking System Standard]].<ref name="Inverse 2017">[https://www.inverse.com/article/29948-nasa-deep-space-gateway-transport-architectures-mars-travel NASA Unveils the Keys to Getting Astronauts to Mars and Beyond] {{Webarchive|url=https://web.archive.org/web/20190727061415/https://www.inverse.com/article/29948-nasa-deep-space-gateway-transport-architectures-mars-travel |date=27 July 2019}} Neel V. Patel, ''The Inverse'' - April 4, 2017</ref>

<!-- Only modules which have been approved (listed in the "Planned modules" section) can be represented here --><div style="white-space: nowrap">
{{Chart/start|style=font-size:80%;line-height:100%;line-width:100%;padding:15px;border:2px dotted #AAA;
}} <!--background:#eee;  padding:0.5em;-->
{{Chart| | |SA|~|PPE|~|SA| | |
| PPE             = [[Astronomy:Power and Propulsion Element|'''PPE'''<br/>{{Nowrap|propulsion module}}]]
| SA              = [[Astronomy:Roll Out Solar Array#Applications|{{Nowrap|Solar Array}}]]
| boxstyle_PPE    = border: 2px solid #fee067; background:#ffffff;
| boxstyle_SA     = border: 2px solid #fee067; background:#ffffff;
}}
{{Chart| | | | | | | |:| ||  | | }}
{{Chart| | | | | | | |:| ||  | | }}
{{Chart| | | | |Canadarm3|:|HLCS| | |
| Canadarm3          = Canadarm3<br/>{{Nowrap|robotic arm}}
| boxstyle_Canadarm3 = border: 2px solid #fee067; background:#ffffff;
| HLCS          = [[Astronomy:European System Providing Refueling, Infrastructure and Telecommunications|ESPRIT-HLCS<br/>{{Nowrap|telecommunications}}]]
| boxstyle_HLCS = border: 2px solid #fee067; background:#ffffff;
}}
{{Chart| | | | | | |:|:|:| | | | }}
{{Chart| | |HLSD|-|HALO|-|ERM|-|CD| |
| HLSD            = [[Astronomy:Artemis program#Human Landing System (HLS)|HLS<br/>{{Nowrap|docking port}}]]
| HALO            = [[Astronomy:Habitation and Logistics Outpost|'''HALO'''<br/>{{Nowrap|logistics and habitat}}]]
| ERM          = [[Astronomy:European System Providing Refueling, Infrastructure and Telecommunications|'''ESPRIT-ERM'''<br/>{{Nowrap|observation port<br/>and cargo storage}}]]
| CD              = [[Astronomy:Gateway Logistics Services|Cargo<br/>{{Nowrap|docking port}}]]
| boxstyle_HLSD   = border: 2px solid #a3ff66; background:#ffffff;
| boxstyle_HALO   = border: 2px solid #6699ff; background:#ffffff;
| boxstyle_ERM = border: 2px solid #6699ff; background:#ffffff;
| boxstyle_CD     = border: 2px solid #a3ff66; background:#ffffff;
}}
{{Chart| | | | | | | |!| | |FS| |
| FS  = {{Nowrap|Fuel storage}}
| boxstyle_FS     = border: 2px solid #fee067; background:#ffffff;
}}
{{Chart| | | | | | | |!| | | | | }}
{{Chart| | |RAD|~|7|!|F|~|RAD| |
| RAD              = Heat radiator
| boxstyle_RAD     = border: 2px solid #fee067; background:#ffffff;
}}
{{Chart| | | | | | |:|!|:| | }}
{{Chart| | |DP|-|I-HAB|-|DP| | | | |
| I-HAB           = [[Astronomy:International Habitation Module|'''I-HAB'''<br/>{{Nowrap|logistics and habitat}}]]
| DP              = {{Nowrap|Docking port}}
| boxstyle_I-HAB  = border: 2px solid #6699ff; background:#ffffff;
| boxstyle_DP     = border: 2px solid #a3ff66; background:#ffffff;
}}
{{Chart| | | | | | | |!| | | | | | }}
{{Chart| | | | | | |OD| | |
| OD              = [[Engineering:Orion (spacecraft)|Orion<br/>{{Nowrap|docking port}}]]
| boxstyle_OD     = border: 2px solid #a3ff66; background:#ffffff;
}}
{{Chart/end|nocat=1}}</div>

=== Planned modules ===
* {{Anchor|PPE|Power and Propulsion Element}} The '''[[Astronomy:Power and Propulsion Element|Power and Propulsion Element]]''' (PPE) started development at the [[Organization:Jet Propulsion Laboratory|Jet Propulsion Laboratory]] during the now canceled [[Astronomy:Asteroid Redirect Mission|Asteroid Redirect Mission]]. The original concept was a robotic, high-performance [[Engineering:Ion thruster|solar electric]] spacecraft that would retrieve a multi-ton boulder from an asteroid and bring it to lunar orbit for study.<ref>{{cite web |url=http://www.nasa.gov/feature/jpl/jpl-seeks-robotic-spacecraft-development-for-asteroid-redirect-mission|title=JPL Seeks Robotic Spacecraft Development for Asteroid Redirect Mission|last=Greicius|first=Tony |date=2016-09-20|publisher=NASA|access-date=30 May 2019|archive-date=17 June 2019|archive-url=https://web.archive.org/web/20190617075954/https://www.nasa.gov/feature/jpl/jpl-seeks-robotic-spacecraft-development-for-asteroid-redirect-mission/|url-status=live}} {{PD-notice}}</ref> When ARM was canceled, the solar electric propulsion was repurposed for the Gateway.<ref>{{cite web |url=https://spacenews.com/nasa-closing-out-asteroid-redirect-mission/|title=NASA closing out Asteroid Redirect Mission|date=2017-06-14|publisher=SpaceNews|access-date=30 May 2019}}</ref><ref>{{cite web |url=https://www.jpl.nasa.gov/missions/asteroid-redirect-robotic-mission-arrm/|title=Asteroid Redirect Robotic Mission|website=jpl.nasa.gov|publisher=NASA|access-date=30 May 2019|archive-date=30 May 2019 |archive-url=https://web.archive.org/web/20190530113407/https://www.jpl.nasa.gov/missions/asteroid-redirect-robotic-mission-arrm/|url-status=live}} {{PD-notice}}</ref> The PPE will allow access to the entire lunar surface and act as a [[Engineering:Space tug|space tug]] for visiting craft.<ref name="Maxar"/> It will also serve as the command and communications center of the Gateway.<ref>{{cite web|url=http://www.sci-news.com/space/deep-space-gateway-transport-mars-moon-exploration-04756.html|title=Deep Space Gateway and Transport: Concepts for Mars, Moon Exploration Unveiled|date=4 April 2017 |publisher=Science News|access-date=2019-05-30|archive-date=30 May 2019|archive-url=https://web.archive.org/web/20190530113409/http://www.sci-news.com/space/deep-space-gateway-transport-mars-moon-exploration-04756.html|url-status=live}}</ref><ref>{{cite web |url=https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/|title=NASA chooses Maxar to build keystone module for lunar Gateway station|last=Clark |first=Stephen|publisher=Spaceflight Now|access-date=2019-05-30|archive-date=5 June 2019|archive-url=https://web.archive.org/web/20190605140715/https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/|url-status=live}}</ref> The PPE is intended to have a launch mass of {{cvt|5000|kg}} with propellant accounting for half that mass <ref name='Boyle'>{{cite web|last=Boyle|first=Alan| url=https://www.geekwire.com/2019/nasa-says-maxar-will-build-first-big-piece-gateway-space-outpost-lunar-orbit/|title=NASA says Maxar will build the first big piece for Gateway station in lunar orbit|publisher=GeekWire|date=23 May 2019|access-date=28 August 2023}}</ref> and the capability to generate 50&nbsp;kW<ref name='Nov 3'>{{cite web|last=Foust|first=Jeff |url=https://spacenews.com/nasa-issues-study-contracts-for-deep-space-gateway-element/|title=NASA issues study contracts for Deep Space Gateway element|publisher=SpaceNews|date=3 November 2017|access-date=11 December 2019}}</ref> of [[Physics:Solar energy|solar electric power]] for its [[Engineering:Ion thruster|ion thruster]]s, which can be supplemented by chemical propulsion.<ref name="Flight_20170406">{{cite web|last1=Chris Gebhardt|title=NASA finally sets goals, missions for SLS – eyes multi-step plan to Mars|date=6 April 2017|url=https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars|publisher=NASASpaceFlight.com|access-date=April 9, 2017|archive-date=21 August 2017|archive-url=https://web.archive.org/web/20170821221210/https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/|url-status=live}}</ref> In May 2019, [[Company:Maxar Technologies|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 [[Engineering:Satellite bus|satellite bus]]. The PPE will use [[Company:Busek|Busek]] 6&nbsp;kW [[Physics:Hall-effect thruster|Hall-effect thruster]]s and [[Organization:NASA|NASA]] [[Astronomy:Advanced Electric Propulsion System|Advanced Electric Propulsion System]] (AEPS) Hall-effect thrusters.<ref name="PPE_Maxar">{{cite news|last=Foust|first=Jeff|title=NASA selects Maxar to build first Gateway element|url=https://spacenews.com/nasa-selects-maxar-to-build-first-gateway-element|access-date=May 23, 2019|publisher=SpaceNews|date=May 23, 2019}}</ref><ref name=":3">[https://www.researchgate.net/profile/R_Cassady/publication/328997773_Status_of_Advanced_Electric_Propulsion_Systems_for_Exploration_Missions/links/5beee33692851c6b27c37074/Status-of-Advanced-Electric-Propulsion-Systems-for-Exploration-Missions.pdf Status of Advanced Electric Propulsion Systems for Exploration Missions.] {{Webarchive |url=https://web.archive.org/web/20190613101313/https://www.researchgate.net/profile/R_Cassady/publication/328997773_Status_of_Advanced_Electric_Propulsion_Systems_for_Exploration_Missions/links/5beee33692851c6b27c37074/Status-of-Advanced-Electric-Propulsion-Systems-for-Exploration-Missions.pdf|date=13 June 2019}} R. Joseph Cassady, Sam Wiley, Jerry Jackson, Aerojet Rocketdyne, October 2018</ref><ref name=":4" /> Maxar was awarded a firm-fixed-price contract of US$375 million to build the PPE. NASA is supplying the PPE with an [[Astronomy:S band|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.<ref name="Maxar_PPE_20190524">{{cite news|last=Clark|first=Stephen|title=NASA chooses Maxar to build keystone module for lunar Gateway station |url=https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station|publisher=Spaceflight Now|date=May 24, 2019|access-date=13 July 2019|archive-date=5 June 2019 |archive-url=https://web.archive.org/web/20190605140715/https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/|url-status=live}}</ref> NASA awarded a contract of US$331.8 million to launch PPE on a [[Company:SpaceX|SpaceX]] [[Engineering:Falcon Heavy|Falcon Heavy]] in November 2025 with the HALO module.<ref name="nasa-20210709" /><ref name="nasa-20210209" />

* {{Anchor|HALO|Habitation and Logistics Outpost}} The '''[[Astronomy:Habitation and Logistics Outpost|Habitation and Logistics Outpost]]''' (HALO),<ref name='HALO 2'>{{cite web|last=Foust|first=Jeff|url=https://spacenews.com/iss-partners-endorse-modified-gateway-plans/|title=ISS partners endorse modified Gateway plans|publisher=SpaceNews|date=30 August 2019|access-date=11 December 2019}}</ref><ref name='HALO 1'>[https://www.nasa.gov/press-release/nasa-asks-american-companies-to-deliver-supplies-for-artemis-moon-missions NASA Asks American Companies to Deliver Supplies for Artemis Moon Missions.] NASA Press Release M019-14, 23 August 2019 {{PD-notice}}</ref> also called the Minimal Habitation Module (MHM) and formerly known as the Utilization Module,<ref>{{cite web|author1=Planetary Society|title=Humans in Deep Space|url=http://www.planetary.org/explore/space-topics/space-missions/humans-in-deep-space.html|website=planetary.org|access-date=6 August 2019|archive-date=17 November 2019|archive-url=https://web.archive.org/web/20191117234651/https://www.planetary.org/explore/space-topics/space-missions/humans-in-deep-space.html|url-status=live}}</ref> will be built by [[Company:Northrop Grumman Innovation Systems|Northrop Grumman Innovation Systems]] (NGIS).<ref name='SN 23July2019'>{{cite web|last=Foust|first=Jeff|url=https://spacenews.com/nasa-to-sole-source-gateway-habitation-module-to-northrop-grumman/|title=NASA to sole source Gateway habitation module to Northrop Grumman|publisher=SpaceNews|date=23 July 2019|access-date=11 December 2019}}</ref><ref name="MHM_requirements_justification">{{cite web|title=Justification for other than full and open competition (JOFOC) for the Minimal Habitation Module (MHM)|url=https://www.fbo.gov/index.php?tab=documents&tabmode=form&subtab=core&tabid=d4e9e11d78e9dd0b8bd05395b3d82c7f|publisher=Federal Business Opportunities|access-date=23 July 2019|ref=Solicitation 80JSC019GTWYHAB|archive-date=3 September 2019|archive-url=https://web.archive.org/web/20190903173343/https://www.fbo.gov/index.php?tab=documents&tabmode=form&subtab=core&tabid=d4e9e11d78e9dd0b8bd05395b3d82c7f|url-status=live}} {{PD-notice}}</ref> A single [[Engineering:Falcon Heavy|Falcon Heavy]] will launch HALO in November 2025 along with the PPE module.<ref name="nasa-20210709" /><ref name="nasa-20210209" /> The HALO is based directly on a [[Engineering:Cygnus (spacecraft)|Cygnus]] Cargo resupply module<ref name='SN 23July2019'/><ref name="NSF07082020">{{cite web|last1=Gebhardt|first1=Chris|title=Northrop Grumman outlines HALO plans for Gateway's central module|date=7 August 2020|url=https://www.nasaspaceflight.com/2020/08/northrop-halo-plans-gateway/|publisher=NASASpaceFlight.com|access-date=13 August 2020|archive-date=10 August 2020|archive-url=https://web.archive.org/web/20200810151335/https://www.nasaspaceflight.com/2020/08/northrop-halo-plans-gateway/|url-status=live}}</ref> to the outside of which radial docking ports, body mounted radiators (BMRs), batteries and communications antennae will be added. The HALO will be a scaled-down habitation module,<ref name='Arc July2019'>{{cite web|last=Messier|first=Doug|url=http://www.parabolicarc.com/2019/07/23/nasa-awards-contract-to-northrop-grumman-for-lunar-gateway-habitat-module/|title=NASA Awards Contract to Northrop Grumman for Gateway Habitat Module|publisher=Parabolic Arc|date=23 July 2019|access-date=11 December 2019|archive-date=29 July 2019|archive-url=https://web.archive.org/web/20190729005145/http://www.parabolicarc.com/2019/07/23/nasa-awards-contract-to-northrop-grumman-for-lunar-gateway-habitat-module/|url-status=dead}}</ref> 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 [[Engineering:Life support system|life support system]]s to augment the Orion spacecraft and support a crew of four for at least 30 days.<ref name="MHM_requirements_justification"/> The overall HALO mass is expected to be 8-9 tons depending on the final internal layout configuration and launch vehicle lift capability.<ref>{{Cite web |last=Evans |first=Ben |date=2021-07-10 |title=NASA, Northrop Grumman Finalize Lunar Gateway Integration Contract|url=https://www.americaspace.com/2021/07/10/nasa-northrop-grumman-finalize-lunar-gateway-integration-contract/ |access-date=2023-08-11 |website=AmericaSpace |language=en-US}}</ref> On 5 June 2020, [[Company:Northrop Grumman Innovation Systems|Northrop Grumman Innovation Systems]] was awarded a contract, by NASA, of US$187 million to complete the preliminary design of HALO.<ref name="SFN20200610">{{cite web|url=https://spaceflightnow.com/2020/06/09/nasa-signs-gateway-habitat-design-contract-with-northrop-grumman/|title=NASA signs Gateway habitat design contract with Northrop Grumman|publisher=Spaceflight Now|date=9 June 2020|access-date=10 June 2020|archive-date=10 June 2020|archive-url=https://web.archive.org/web/20200610222822/https://spaceflightnow.com/2020/06/09/nasa-signs-gateway-habitat-design-contract-with-northrop-grumman/|url-status=live}}</ref> On 9 July 2021, NASA signed a separate contract with Northrop for the fabrication of the HALO, and for integration with the PPE being built by Maxar, for US$935 million.<ref name="nasa-20210709" /> In July 2022, Northrop Grumman awarded [[Company:Solstar|Solstar]] a contract to supply Wi-Fi access for personnel and equipment in the HALO module.<ref>{{Cite web |last=Werner |first=Debra |date=2022-07-18 |title=Northrop Grumman taps Solstar for HALO Module Wi-Fi |url=https://spacenews.com/solstar-halo-wi-fi/ |access-date=2023-01-13 |website=SpaceNews |language=en-US}}</ref><ref>{{Cite web |title=NM firm builds Wi-Fi 'hotspot' for NASA moon station |url=https://news.yahoo.com/nm-firm-builds-wi-fi-035900403.html |access-date=2023-01-13 |website=news.yahoo.com |date=3 August 2022 |language=en-US}}</ref>

* {{Anchor|ESPRIT}} [[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, {{wipe|France}}]] The '''European System Providing Refueling, Infrastructure and Telecommunications''' (ESPRIT) service module will provide additional xenon and hydrazine capacity, additional communications equipment, and an airlock for science packages.<ref name=nsf-20180911>{{cite web|url=https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/|title=NASA updates lunar Gateway plans|date=September 11, 2018|first=Philip|last=Sloss|publisher=NASASpaceFlight.com|access-date=15 September 2018|archive-date=6 August 2019|archive-url=https://web.archive.org/web/20190806063256/https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/|url-status=live}}</ref> It will have a mass of approximately {{cvt|4000|kg}}, and a length of {{cvt|3.91|m}}.<ref name='ESPRIT Zak'>[http://www.russianspaceweb.com/imp-lcub.html ESA develops logistics vehicle for cis-lunar outpost] {{Webarchive |url=https://web.archive.org/web/20181004042145/http://russianspaceweb.com/imp-lcub.html|date=4 October 2018}} Anatoly Zak, ''RussianSpaceWeb.com'' 8 September 2018</ref> ESA has awarded two parallel design studies, one mostly led by Airbus in partnership with Comex and OHB<ref>[https://comex.fr/en/2018/11/21/comex-and-airbus-join-forces-around-a-module-of-the-future-lunar-station/ Comex and Airbus join forces around a module of the future lunar station] {{Webarchive|url=https://web.archive.org/web/20190729152604/https://comex.fr/en/2018/11/21/comex-and-airbus-join-forces-around-a-module-of-the-future-lunar-station/|date=29 July 2019}} ''Comex'', press release, 21 November 2018</ref> and one led by Thales Alenia Space.<ref>{{cite web|url=https://www.thalesgroup.com/fr/monde-espace/orbital-infrastructure-and-space-transport/magazine/retour-lune-pas-vers-nouvelles|title=Back to the Moon, a step towards future exploration missions|date=5 August 2019 |access-date=7 August 2020|archive-date=22 October 2020|archive-url=https://web.archive.org/web/20201022063112/https://www.thalesgroup.com/fr/monde-espace/orbital-infrastructure-and-space-transport/magazine/retour-lune-pas-vers-nouvelles|url-status=live}}</ref> The construction of the module was approved in November 2019.<ref name='SR_Dec2019'>[https://www.thespacereview.com/article/3843/1 Funding Europe's space ambitions] {{Webarchive |url=https://web.archive.org/web/20191229115217/https://www.thespacereview.com/article/3843/1|date=29 December 2019}} Jeff Foust, ''The Space Review'' December 2019</ref><ref name='Hebden_Nov2019'>[https://room.eu.com/news/hera-mission-is-approved-as-esa-receives-biggest-ever-budget Hera mission is approved as ESA receives biggest ever budget] {{Webarchive |url=https://web.archive.org/web/20191210155035/https://room.eu.com/news/hera-mission-is-approved-as-esa-receives-biggest-ever-budget|date=10 December 2019}} Kerry Hebden, ''Room'' 29 November 2019</ref> On 14 October 2020, Thales Alenia Space announced that they had been selected by the European Space Agency (ESA) to build the ESPRIT module.<ref name=":0">{{cite news|url=https://www.bbc.com/news/science-environment-54537906|title=Europe steps up contributions to Artemis Moon plan|publisher=BBC News|date=2020-10-14|access-date=14 October 2020|archive-date=14 October 2020|archive-url=https://web.archive.org/web/20201014104207/https://www.bbc.com/news/science-environment-54537906|url-status=live}}</ref><ref name=":1">{{cite web|title=Thales Alenia Space on its way to reach the Moon |url=https://www.thalesgroup.com/en/worldwide/space/press-release/thales-alenia-space-its-way-reach-moon|website=thalesgroup.com|date=14 October 2020 |access-date=14 October 2020}}</ref> Early 2021, Thales Alenia Space announced effective contract signature.<ref>{{Cite web|url=https://www.thalesgroup.com/en/worldwide/space/news/thales-alenia-space-heart-lunar-industrial-challenges|title=Thales Alenia Space: at the heart of lunar industrial challenges|website=Thales Group|date=7 January 2021 }}</ref> The ESPRIT module will consist of two parts. The first part, called the Halo Lunar Communication System (HLCS) will provide the communications for the mini-station Gateway. It will launch in November 2025 pre-attached to the HALO module, for which Thales has separately been awarded a contract by [[Organization:NASA|NASA]] to construct its hull and micrometeoroid protection. The second part, called the ESPRIT Refueling Module (ERM), will contain the pressurized fuel tanks, docking ports and small-windowed habitation corridor<ref name=":0"/><ref name=":1"/> and launch in 2029.<ref name="sn-20230313" />

* {{anchor|I-HAB|International Habitation Module|IHAB}} The '''[[Astronomy:International Habitation Module|International Habitation Module]]''' (I-HAB) will be an additional habitation module built by ESA in collaboration with {{wipe|Japan}}.<ref name='SR_Dec2019'/> On 14 October 2020, [[Company:Thales Alenia Space|Thales Alenia Space]] announced that they had been selected by ESA to build the I-HAB module slated for launch in 2026. The module will also feature contributions from the other station partners, including a life support system from [[Organization:JAXA|JAXA]], avionics and software from [[Organization:NASA|NASA]] and robotics from the [[Organization:Canadian Space Agency|Canadian Space Agency]] (CSA).<ref name=":0"/><ref name=":1"/> The module is slated to launch in 2028 on the Artemis 4 mission as a co-manifested payload on the SLS Block 1B along with a crewed Orion spacecraft.<ref name="sn-20230313">{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/nasa-planning-to-spend-up-to-1-billion-on-space-station-deorbit-module/ |title=NASA planning to spend up to $1 billion on space station deorbit module |work=SpaceNews |date=13 March 2023 |access-date=13 March 2023}}</ref> The I-HAB would have a maximum launch mass of {{cvt|10000|kg}} and provide a habitable volume of {{cvt|10|m3}} (the gross pressurized volume is {{cvt|35|m3}}.<ref name="esaArtemis4">{{cite web |last= |first= |url=https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/Orion/Artemis_IV |title=Artemis IV |work=[[Organization:European Space Agency|European Space Agency]] |date= |access-date=26 August 2023}}</ref> In 2019, NASA proposed the addition of a second large U.S. habitation module (to be developed by U.S. industry) in order to increase the station's combined habitable volume to {{cvt|125|m3}}.<ref name=nsf-20180911/>
* {{anchor|Canadarm3|Canadarm 3}} The '''Canadarm3''', a pair of robotic remote manipulator arms, one large and one small, broadly similar to the Space Shuttle [[Engineering:Canadarm|Canadarm]] and International Space Station [[Engineering:Mobile Servicing System|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.<ref>{{Cite web |last=Agency |first=Canadian Space |date=2020-06-26 |title=About Canadarm3 |url=https://www.asc-csa.gc.ca/eng/canadarm3/about.asp |access-date=2023-09-19 |website=Canadian Space Agency}}</ref> The Canadarm3 is to be the contribution of the [[Organization:Canadian Space Agency|Canadian Space Agency]] (CSA) to this international endeavor. CSA contracted MDA (formerly MacDonald, Dettwiler and Associates) to build the arm. MDA previously built Canadarm2, while its former subsidiary, Spar Aerospace, built [[Engineering:Canadarm|Canadarm]].<ref name="GC-CSA-20200626">{{cite web |author=Canadian Space Agency |date=26 June 2020 |title=Building the next Canadarm |url=https://www.canada.ca/en/space-agency/news/2020/06/building-the-next-canadarm.html |publisher=Government of Canada}}</ref><ref name="CTV-1.5221827">{{cite news |date=8 December 2020 |title=Canadian Space Agency awards Canadarm3 contract worth $22.8 million to MDA |publisher=CTV News |agency=The Canadian Press |url=https://www.ctvnews.ca/sci-tech/canadian-space-agency-awards-canadarm3-contract-worth-22-8m-to-mda-1.5221827}}</ref><ref name="Yahoo-143000109">{{cite news |author=MDA |date=8 December 2020 |title=MDA Announces Contract for Canadarm3 on NASA-led Gateway |publisher=Yahoo News |agency=CNW |url=https://www.yahoo.com/now/mda-announces-contract-canadarm3-nasa-143000109.html |url-status=dead |access-date=17 December 2020 |archive-url=https://web.archive.org/web/20210428040544/https://www.yahoo.com/now/mda-announces-contract-canadarm3-nasa-143000109.html |archive-date=28 April 2021}}</ref>

* {{anchor|Crew and Science Airlock}} The '''Crew and Science Airlock''' module will be used for performing [[Astronomy:Extravehicular activity|extravehicular activities]] outside the mini-space station and would have the docking port for the proposed [[Astronomy:Deep Space Transport|Deep Space Transport]]. It will be built by the [[Place:United Arab Emirates|UAE]]'s [[Engineering:Mohammed bin Rashid Space Centre|Mohammed bin Rashid Space Centre]] (MBRSC), and is slated for launch around 2030.<ref name="sn-20240107">{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/uae-to-build-airlock-for-lunar-gateway/ |title=UAE to build airlock for lunar Gateway |work=SpaceNews |date=7 January 2024 |access-date=7 January 2024}}</ref>

=== Proposed modules ===
[[File:Lunar Orbital Platform-Gateway.jpg|thumb|(Outdated) artist's concept of Lunar Gateway orbiting the Moon. The Orion MPCV is docked on the left.]]
The concept for the Gateway is still evolving, and is intended to include the following modules:<ref>{{cite web|url=https://www.nasa.gov/sites/default/files/atoms/files/20180327-crusan-nac-heoc-v8.pdf |title=Future Human Exploration Planning:Lunar Orbital Platform – Gateway and Science Workshop Findings|last=Cursan|first=Jason|date=March 27, 2018|access-date=13 April 2018|archive-date=1 June 2019|archive-url=https://web.archive.org/web/20190601195248/https://www.nasa.gov/sites/default/files/atoms/files/20180327-crusan-nac-heoc-v8.pdf|url-status=live}} {{PD-notice}}</ref>

* {{anchor|Gateway Logistics Module|Gateway Logistics Modules}} The '''Gateway Logistics Modules''' will be used to refuel, resupply and provide logistics on board the mini-space station. The first logistics module sent to the Gateway will also arrive with a robotic arm, which will be built by the [[Organization:Canadian Space Agency|Canadian Space Agency]] (CSA).<ref>{{cite news|title=Canada's heading to the moon: A look at the Gateway |url=https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522|last1=Mortillaro|first1=Nicole|publisher=CBC News|date=February 28, 2019|access-date=2 March 2019|archive-date=2 March 2019|archive-url=https://web.archive.org/web/20190302004136/https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522|url-status=live}}</ref><ref>{{cite news|url=https://globalnews.ca/news/3775926/canadian-space-agency-robotic-arms/|title=Canadian Space Agency to build robotic arms for lunar space station|publisher=Global News|access-date=29 September 2017|archive-date=29 September 2017|archive-url=https://web.archive.org/web/20170929130437/https://globalnews.ca/news/3775926/canadian-space-agency-robotic-arms/|url-status=live}}</ref>

== Construction ==
Crewed flights to the Gateway are expected to use Orion and SLS, while other missions are expected to be done by commercial launch providers. In March 2020, NASA announced [[Company:SpaceX|SpaceX]] with its future spacecraft [[Engineering:Dragon XL|Dragon XL]] as the first commercial partner to deliver supplies to the Gateway (see [[Astronomy:Gateway Logistics Services|GLS]]).<ref>{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/spacex-wins-nasa-commercial-cargo-contract-for-lunar-gateway/ |title=SpaceX wins NASA commercial cargo contract for lunar Gateway |work=SpaceNews |date=27 March 2020 |access-date=27 March 2020}}</ref>

===Phase 1===
The first two modules (PPE and HALO) will be launched together on the [[Engineering:Falcon Heavy|Falcon Heavy]] rocket in November 2025.<ref name="nasa-20210709" /><ref name="nasa-20210209">{{cite web |url=https://www.nasa.gov/press-release/nasa-awards-contract-to-launch-initial-elements-for-lunar-outpost |title=NASA Awards Contract to Launch Initial Elements for Lunar Outpost |work=[[Organization:NASA|NASA]] |date=9 February 2021 |access-date=9 February 2021}}</ref>

{| class="wikitable"
!Year
!Mission objective
!Mission name
!Launch vehicle
!Human/robotic elements
|-

| November 2025<ref name="nasa-20210709" />
| Launch of [[Astronomy:Power and Propulsion Element|Power and Propulsion Element]] (PPE) and [[Astronomy:Habitation and Logistics Outpost|Habitation and Logistics Outpost]] (HALO)
| Mini-space station Gateway
| [[Engineering:Falcon Heavy|Falcon Heavy]]
| Robotic
|-

| December 2025<ref name="sn-20230313" />
| Delivery of [[Engineering:Orion (spacecraft)|Orion MPCV]] (with crew, for lunar landing)
| [[Astronomy:Artemis 3|Artemis 3]]
| [[Astronomy:Space Launch System|SLS Block 1]]
| Crewed
|-

| September 2028<ref name="sn-20230313" />
| Delivery of Orion MPCV and [[Astronomy:International Habitation Module|I-HAB]] module<ref name="fy2022_request" />
| [[Astronomy:Artemis 4|Artemis 4]]
| SLS Block 1B
| Crewed
|-

| September 2029<ref name="sn-20230313" />
| Delivery of Orion MPCV and [[Astronomy:European System Providing Refueling, Infrastructure and Telecommunications|ESPRIT]] Refueling Module (ERM)<ref>{{cite web |last=Foust |first=Jeff |url=https://spacenews.com/nasa-foresees-gap-in-lunar-landings-after-artemis-3/ |title=NASA foresees gap in lunar landings after Artemis 3 |work=SpaceNews |date=20 January 2022 |access-date=6 February 2022}}</ref>
| [[Astronomy:Artemis 5|Artemis 5]]
| SLS Block 1B
| Crewed
|-



| September 2030<ref name="sn-20230313" />
| Delivery of Orion MPCV and Crew and Science Airlock module
| Artemis 6
| SLS Block 1B
| Crewed
|-

| September 2031<ref name="sn-20230313" />
| '''(Proposed)''' Delivery of Orion MPCV and logistics module
| Artemis 7
| SLS Block 1B
| Crewed
|}

== Criticism ==
NASA officials promote the Gateway as a "reusable command module" that could direct activities on the lunar surface.<ref name='SN Foust 25 December 2018'>[https://spacenews.com/is-the-gateway-the-right-way-to-the-moon/ Is the Gateway the right way to the Moon?] Jeff Foust, ''SpaceNews'' 25 December 2018</ref>  However, Gateway has received mostly negative reactions from space professionals.

Michael D. Griffin, a former NASA administrator, said that the Gateway could be useful only after there are facilities on the Moon producing propellant that could be transported to the Gateway. Griffin thinks that after that is achieved, the Gateway would then serve as a fuel depot.<ref name='SN Foust 25 December 2018'/>  In a written testimony to Congress, Griffin stated that the current architecture requiring staging operations at a Gateway based in a lunar polar near-rectlinear halo orbit (NRHO) with a 6.5-day period was disadvantageous in that immediate return to the Gateway from the lunar surface is possible only on 6.5-day centers and that no early human lunar mission should knowingly accept the risk of stranding a crew, whether on the surface or in lunar orbit, for days at a time.<ref>{{cite web|last1=Griffin|first1=Michael|title=Returning to the Moon: Keeping Artemis on Track|url=https://republicans-science.house.gov/_cache/files/2/d/2dc97bb6-040b-4d15-ae69-6b8de637174d/448A0B95841995613C9A9B19135C104C.2024-01-17-griffin---testimony.pdf/|date=17 January 2024|access-date=19 January 2024}}</ref>

Clive Neal, a University of Notre Dame geologist and advocate for the lunar exploration program, called the Gateway "a waste of money" and stated that NASA is "not fulfilling space policy by building an orbital space station around the Moon".<ref>{{cite web|last1=Berger|first1=Eric|title=We got a leaked look at NASA's future Moon missions—and likely delays|url=https://arstechnica.com/science/2022/06/we-got-a-leaked-look-at-nasas-future-moon-missions-and-likely-delays/|newspaper=Ars Technica|date=20 June 2022|access-date=27 June 2020}}</ref>

Former NASA Associate Administrator Doug Cooke wrote in an article on ''The Hill'' stating, "NASA can significantly increase speed, simplicity, cost and probability of mission success by deferring Gateway, leveraging SLS, and reducing critical mission operations". He also wrote, "NASA should launch the lander elements (ascent and descent/transfer) on an SLS Block 1B. If an independent transfer element is required, it can be launched on a commercial launcher".<ref>{{cite web|last1=Cooke|first1=Doug|title=Getting back to the moon requires speed and simplicity |url=https://thehill.com/opinion/technology/461299-getting-back-to-the-moon-requires-speed-and-simplicity|newspaper=The Hill|date=13 September 2019|access-date=20 September 2019|archive-date=20 September 2019|archive-url=https://web.archive.org/web/20190920121323/https://thehill.com/opinion/technology/461299-getting-back-to-the-moon-requires-speed-and-simplicity|url-status=live}}</ref>

George Abbey, a former director of NASA's [[Organization:Johnson Space Center|Johnson Space Center]], said, "The Gateway is, in essence, building a space station to orbit a natural space station, namely the Moon. [...] If we are going to return to the Moon, we should go directly there, not build a space station to orbit it".<ref>{{cite web|last1=Abbey|first1=George|title=The Moon is "a God-given space station orbiting Earth" [Opinion] |url=https://www.houstonchronicle.com/opinion/outlook/article/The-moon-is-a-God-given-space-station-orbiting-14092345.php|newspaper=Houston Chronicle|date=13 July 2019|access-date=20 September 2019|archive-date=20 September 2019|archive-url=https://web.archive.org/web/20190920155132/https://www.houstonchronicle.com/opinion/outlook/article/The-moon-is-a-God-given-space-station-orbiting-14092345.php|url-status=live}}</ref>

Former NASA astronaut Terry W. Virts, who was a pilot of [[Engineering:STS-130|STS-130]] aboard {{OV|105}} and commander of the ISS on [[Astronomy:Expedition 43|Expedition 43]], wrote in an op-ed on ''[[Ars Technica]]'' that the Gateway would "shackle human exploration, not enable it". He also said, "If we don't have the goal [of Gateway], we are putting the proverbial chicken before the egg by developing "[[Astronomy:Project Gemini|Gemini]]" before we know what "[[Astronomy:Apollo program|Apollo]]" will look like. Regardless of a future destination, as someone who lived on the ISS for 200 days, I cannot envision a new technology that would be developed or validated by building another modular space station. Without a specific goal, we're unlikely to ever identify one". Terry further criticized NASA for abandoning its planned goal of separating crew from cargo, which was put in place following the [[Engineering:Space Shuttle Columbia disaster|Space Shuttle ''Columbia'' disaster]] in 2003.<ref>{{cite web|title=Op-ed: The Deep Space Gateway would shackle human exploration, not enable it|date=28 September 2017|url=https://arstechnica.com/science/2017/09/op-ed-the-deep-space-gateway-would-shackle-human-exploration-not-enable-it/|publisher=Ars Technica|access-date=20 May 2018|archive-date=21 May 2018|archive-url=https://web.archive.org/web/20180521104209/https://arstechnica.com/science/2017/09/op-ed-the-deep-space-gateway-would-shackle-human-exploration-not-enable-it/|url-status=live}}</ref> [[Engineering:Apollo 11|Apollo 11]] astronaut [[Biography:Buzz Aldrin|Buzz Aldrin]] stated that he is "quite opposed to the Gateway" and that "using the Gateway as a staging area for robotic or human missions to the lunar surface is absurd". Aldrin also questioned the benefit of the idea of sending "a crew to an intermediate point in space, pick up a lander there and go down". Conversely, Aldrin expressed support for [[Biography:Robert Zubrin|Robert Zubrin]]'s Moon Direct concept which involves lunar landers traveling from Earth orbit to the lunar surface and back.<ref name="spacenews_lunar-exploration-plans">{{cite web|url=https://spacenews.com/advisory-group-skeptical-of-nasa-lunar-exploration-plans/ |title=Advisory group skeptical of NASA lunar exploration plans|last1=Foust|first1=Jeff|date=16 November 2018|publisher=SpaceNews|access-date=20 December 2018}}</ref>

Pei Zhaoyu, deputy director of the [[Astronomy:Chinese Lunar Exploration Program|Lunar Exploration and Space Program Center]] of the [[Organization:China National Space Administration|China National Space Administration]] (CNSA), concluded that the Gateway would have "low cost-effectiveness".<ref>{{cite web|title=Chinese space official seems unimpressed with NASA's lunar gateway|url=https://arstechnica.com/science/2018/07/chinese-space-official-seems-unimpressed-with-nasas-lunar-gateway/|last1=Berger|first1=Eric|date=17 July 2018|publisher=Ars Technica|access-date=17 July 2018|archive-date=17 July 2018|archive-url=https://web.archive.org/web/20180717155221/https://arstechnica.com/science/2018/07/chinese-space-official-seems-unimpressed-with-nasas-lunar-gateway/|url-status=live}}</ref> Pei said the Chinese plan is to focus on a national research station on the surface.<ref>{{cite web|last1=Kapoglou|first1=Angeliki|url=https://twitter.com/Capoglou/status/1018793732626440192|website=twitter.com|title=twitter.com/Capoglou |access-date=17 July 2018|archive-date=17 July 2018|archive-url=https://web.archive.org/web/20180717155806/https://twitter.com/Capoglou/status/1018793732626440192|url-status=live}}</ref> In July 2019, Pei announced that China was holding discussions with Russia and the ESA on international co-operation<ref>{{Cite web|url=http://www.xinhuanet.com/english/2019-07/22/c_138248065.htm|archive-url=https://web.archive.org/web/20190722141213/http://www.xinhuanet.com/english/2019-07/22/c_138248065.htm|url-status=dead|archive-date=22 July 2019|title = China, Russia, Europe to jointly explore plan for research station on Moon - Xinhua &#124; English.news.cn}}</ref> and in August 2020 unveiled China's concept; the [[Astronomy:International Lunar Research Station|International Lunar Research Station (ILRS)]]<ref>{{Cite web|url=https://spacenews.com/china-is-aiming-to-attract-partners-for-an-international-lunar-research-station/|title=China is aiming to attract partners for an international lunar research station|date=21 August 2020}}</ref> with co-operation from Russia and tentative agreement from ESA.

Architect René Waclavicek, who was involved with the design of the I-HAB module, noted the difficulty of designing a comfortable living quarter for astronauts visiting Gateway. His team was forced to shrink the size of the module to the point where its diameter is just 1.2 meters (4 feet), owing to the limited amount of weight [[Astronomy:Comparison of orbital launch systems|current launch vehicles]] can carry to Lunar orbit and other technical limits. Additionally, most of I-HAB's 8 cubic meters (280 cubic feet) of available space will be filled with life support equipment, leaving a narrow corridor and a total of 1.5 cubic meters (53 cubic feet) of personal space to be shared by four astronauts.<ref>{{Cite web |last=Pultarova |first=Tereza |date=2023-01-08 |title=NASA's moon-orbiting space station will be claustrophobic, architect says |url=https://www.space.com/lunar-gateway-station-claustrophobic-architect-says |access-date=2023-04-04 |website=Space.com |language=en}}</ref>

[[Organization:Mars Society|Mars Society]] founder Robert Zubrin called the Gateway "NASA's worst plan yet" in an article in the ''National Review''. He said, "We do not need a lunar-orbiting station to go to the [[Astronomy:Moon|Moon]]. We do not need such a station to go to [[Astronomy:Mars|Mars]]. We do not need it to go to [[Astronomy:Near-Earth object|near-Earth asteroids]]. We do not need it to go anywhere. Nor can we accomplish anything in such a station that we cannot do in the Earth-orbiting [[Astronomy:International Space Station|International Space Station]], except to expose human subjects to irradiation – a form of medical research for which a number of Nazi doctors were hanged". Zubrin also stated, "If the goal is to build a Moon base, it should be built on the surface of the Moon. That is where the science is, that is where the shielding material is, and that is where the resources to make propellant and other useful things are to be found".<ref>{{cite web|title=NASA's Worst Plan Yet|date=16 May 2017 |url=https://www.nationalreview.com/2017/05/nasa-lunar-orbit-space-station-terrible-idea/ |publisher=National Review|access-date=20 May 2018|archive-date=2 March 2018|archive-url=https://web.archive.org/web/20180302014801/https://www.nationalreview.com/2017/05/nasa-lunar-orbit-space-station-terrible-idea/|url-status=live}}</ref>

Retired aerospace engineer Gerald Black wrote in an article on ''The Space Review'' stating that the Gateway is "useless for supporting human return to the lunar surface and a lunar base". He added that it was not planned to be used as a rocket fuel depot and that stopping at the Gateway on the way to or from the Moon would serve no useful purpose and cost propellant.<ref>[http://thespacereview.com/article/3494/1 The Lunar Orbital Platform – Gateway: an unneeded and costly diversion] {{Webarchive|url=https://web.archive.org/web/20180521104510/http://thespacereview.com/article/3494/1|date=21 May 2018}} Gerald Black, ''The Space Review'' 14 May 2018</ref>

Mark Whittington, a contributor to ''The Hill'' newspaper and an author of several space exploration studies, stated in an article that the "lunar orbit project doesn't help us get back to the Moon". Whittington also pointed out that a lunar orbiting space station was not utilized during the Apollo program and that a "reusable lunar lander could be refueled from a depot on the lunar surface and left in a parking orbit between missions without the need for a big, complex space station".<ref>{{cite web|last1=Whittington|first1=Mark|title=NASA's unnecessary US$504 million lunar orbit project doesn't help us get back to the Moon|url=https://thehill.com/opinion/technology/392611-nasas-unnecessary-504-million-lunar-orbit-project-doesnt-help-us-get-back|newspaper=The Hill|date=16 June 2018|access-date=20 December 2018|archive-date=14 November 2019|archive-url=https://web.archive.org/web/20191114223317/https://thehill.com/opinion/technology/392611-nasas-unnecessary-504-million-lunar-orbit-project-doesnt-help-us-get-back|url-status=live}}</ref>

Astrophysicist Ethan Siegel wrote an article in ''Forbes'' titled "NASA's Idea For A Space Station In Lunar Orbit Takes Humanity Nowhere". Siegel stated that "Orbiting the Moon represents barely incremental progress; the only scientific "advantages" to being in lunar orbit as opposed to [[Astronomy:Low Earth orbit|low Earth orbit]] are twofold: 1. You're outside of the [[Astronomy:Van Allen radiation belt|Van Allen belts]]. 2. You're closer to the lunar surface", reducing the time delay. His final opinion was that the Gateway is "a great way to spend a great deal of money, advancing science and humanity in no appreciable way".<ref>{{cite web|last1=Siegel|first1=Ethan|title=NASA's Idea For A Space Station In Lunar Orbit Takes Humanity Nowhere|url=https://www.forbes.com/sites/startswithabang/2017/05/18/nasas-idea-for-a-space-station-in-lunar-orbit-takes-humanity-nowhere/#221e7593d145 |work=Forbes|access-date=15 February 2019|archive-date=16 February 2019|archive-url=https://web.archive.org/web/20190216153303/https://www.forbes.com/sites/startswithabang/2017/05/18/nasas-idea-for-a-space-station-in-lunar-orbit-takes-humanity-nowhere/#221e7593d145|url-status=live}}</ref>

=== Response from NASA ===
On 10 December 2018, NASA Administrator Jim Bridenstine said at a presentation "There are people who say we need to get there, and we need to get there tomorrow", speaking of a crewed mission to the Moon, countering with "What we're doing here at NASA is following Space Policy Directive 1", speaking of the Gateway and following up with "I would argue that we got there in 1969. That race is over, and we won. The time now is to build a sustainable, reusable architecture. [...] The next time we go to the Moon, we're going to have American boots on the Moon with the American flag on their shoulders, and they're going to be standing side-by-side with our international partners who have never been to the Moon before".<ref>{{cite web|website=spacenews.com|date=15 December 2018|title=Is the Gateway the right way to the moon?|first=Jeff|last=Foust|url=https://spacenews.com/is-the-gateway-the-right-way-to-the-moon/|access-date=20 August 2019}}</ref>

Dan Hartman, the program manager for Gateway, on 30 March 2020, told ''Ars Technica'' that the benefits of using Gateway are extending the mission duration, buying down risk, providing research capability and the capability to re-use ascent modules.<blockquote>When you go single, I'll say direct mission to the Moon, you're limited on the supplies, either with the Lander or with Orion. With the Gateway, with just with one logistics module, we think we can extend to about twice the mission duration, so 30 days to 60 days. Obviously, the more crew time you have in lunar orbit helps us with research in the human aspects of living in deep space. The more duration we have, certainly that'll help us buy down significant risk with the extreme environments that we're going to be subjecting our crews to. Because we've got to go figure out how to operate in deep space. Obviously we'll demonstrate new hardware and offer that sustainable flexible path for our [[Engineering:Lunar Lander (spacecraft)|Lunar Lander]] system. With the Gateway, the thinking is we'll be able to reuse the ascent modules potentially multiple times. And again, if we can get mission duration beyond the 30 days, it's going to offer us some additional environmental capabilities. We think it's a tremendous risk buy down asset, not only to explore the Moon sustainably, but to prove out some things that we need to do to get to Mars.<ref>{{cite web|last1=Eric|first1=Berger|title=NASA officials outline plans for building a lunar Gateway in the mid-2020s|url=https://arstechnica.com/science/2020/03/nasa-officials-outline-plans-for-building-a-lunar-gateway-in-the-mid-2020s/|publisher=Ars Technica|date=30 March 2020|access-date=25 April 2020|archive-date=13 May 2020|archive-url=https://web.archive.org/web/20200513134610/https://arstechnica.com/science/2020/03/nasa-officials-outline-plans-for-building-a-lunar-gateway-in-the-mid-2020s/|url-status=live}}</ref></blockquote>

== See also ==
* {{Annotated link|CAPSTONE (spacecraft)}}
* {{Annotated link|Commercial Resupply Services}}
* {{Annotated link|Exploration Gateway Platform}}
* {{Annotated link|Lunar Orbital Station}}
* {{Annotated link|Moonbase}}
* {{Annotated link|Lunar cycler}}
* {{Annotated link|Orbital Piloted Assembly and Experiment Complex}}
* {{Annotated link|Project Prometheus}}
* {{Annotated link|Mars Base Camp}}
* {{Annotated link|Starship HLS}}
*[[Astronomy:International Lunar Research Station|International Lunar Research Station]]

== References ==
{{Reflist}}

== External links ==
* [https://www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations Deep Space Gateway to Open Opportunities for Distant Destinations] - NASA Moon to Mars
* [http://www.russianspaceweb.com/imp.html First human outpost near the Moon] – RussianSpaceWeb page about the Gateway
* [http://www.russianspaceweb.com/imp-2017.html History of the Gateway planning]

{{NASA space program}}
{{Space stations}}
{{Moon spacecraft}}
{{Artemis program}}
{{Future spaceflights}}

[[Category:Lunar Gateway| ]]
[[Category:Artemis program]]
[[Category:Crewed spacecraft]]
[[Category:Joint ventures]]
[[Category:Missions to the Moon]]
[[Category:NASA programs]]
[[Category:Spacecraft using halo orbits]]

{{Sourceattribution|Lunar Gateway}}