.jpg) An illustration of the Gateway's Power and Propulsion Element (PPE) and Habitation and Logistics Outpost (HALO) in orbit around the Moon | |
 | |
| Station statistics | |
|---|---|
| Crew | 4 maximum (planned) |
| Launch | 2027 (planned)[1] |
| Carrier rocket | Falcon Heavy SLS Block 1B |
| Launch pad | Kennedy Space Center Launch Complex 39 |
| Mission status | In development |
| Pressurisedvolume | ≥125 m3 (4,400 cu ft) (planned)[2] |
| Periselene altitude | 3,000 km (1,900 mi)[3] |
| Aposelene altitude | 70,000 km (43,000 mi) |
| Orbital inclination | Polarnear-rectilinear halo orbit (NRHO) |
| Orbital period | ≈7 days |
| Configuration | |
 Configuration as of 16 November 2022 | |
| Part ofa series on the |
| United States space program |
|---|
  |
National security space |
TheLunar Gateway, or simplyGateway, is aspace station which is planned to be assembled in orbit around theMoon. The Gateway is intended to serve as a communication hub, science laboratory, and habitation module forastronauts as part of theArtemis program. It is a multinational collaborative project: participants includeNASA, theEuropean Space Agency (ESA), theJapan Aerospace Exploration Agency (JAXA), theCanadian Space Agency (CSA), and theMohammed Bin Rashid Space Centre (MBRSC). The Gateway is planned to be the first space station beyondlow Earth orbit.[4][5]
The science disciplines to be studied on the Gateway are expected to includeplanetary science,astrophysics,Earth observation,heliophysics,fundamental space biology, andhuman health and performance.[6] As of April 2024, construction is underway of the initial habitation and propulsion modules.[7][8][9] 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 theMoon, toMars, and deeper into theSolar System.[10]
The project is expected to play a major role in the Artemis program after 2024. NASA's Budget for FY 2025 included $817.7 million for the project.[11] While the project is led by NASA, the Gateway is meant to be developed, serviced, and used in collaboration with theCSA,ESA,JAXA, and commercial partners. It will serve as the staging point for both robotic and crewed exploration of thelunar south pole and is the proposed staging point for NASA'sDeep Space Transport concept for transport to Mars.[12][7][13]
Formerly known as theDeep Space Gateway (DSG), the station was renamedLunar Orbital Platform-Gateway (LOP-G) in NASA's 2018 proposal for the 2019 United States federal budget.[14][15] When the NASA budget was signed into law on February 15, 2019,[16] US$450 million had been committed by Congress to preliminary studies.[16][17]
In November 2019, NASA unveiled the name and logo of the space station inspired by the Americanfrontier symbol of theSt. LouisGateway Arch.[18]
TheApollo Command and Service Module was the first crewed lunar orbiting spacecraft performing dockings and crew transfers with another spacecraft, theApollo Lunar Module.Lunar bases, like the firstTranquility Base as well as concepts for lunar bases have been the main focus of human presence at the Moon.
An earlier NASA proposal for acislunar station had been made public in 2012 and was dubbed theDeep Space Habitat. That proposal led to funding in 2015 under the NextSTEP program to study the requirements of deep space habitats.[19] 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.[20] The solar electricPower and Propulsion Element (PPE) of the Gateway was originally a part of the now-canceledAsteroid Redirect Mission.[21][22]
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.[6] 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.[23]
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.[5] The "Lunar Exploration and Access to Polar Regions", from theUniversity of Puerto Rico at Mayagüez, was the winning concept.[24]
On 27 September 2017, an informal joint statement on cooperation regarding the program between NASA and Russia'sRoscosmos was announced.[9] However, in October 2020Dmitry Rogozin, director general of Roscosmos, said that the program is too “U.S.-centric” for Roscosmos to participate,[25] and in January 2021, Roscosmos announced that it would not participate in the program.[26]
As of January 2024, theCanadian Space Agency (CSA), theEuropean Space Agency (ESA),Japan Aerospace Exploration Agency (JAXA) andMohammed Bin Rashid Space Centre (MBRSC) plan to participate in the Gateway project, each 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 intolunar orbit with some co-manifested with Artemis missions.[27]
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 wereBoeing,Lockheed Martin,Orbital ATK,Sierra Nevada andSpace Systems/Loral.[28][22] These awards are in addition to the ongoing set ofNextSTEP-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,[13] so the Gateway is likely to incorporate components developed under NextSTEP as well.[22][29] The PPE will use four 6 kW BHT-6000BusekHall-effect thrusters[30][31][32] and three 12 kWNASA/Aerojet RocketdyneAdvanced Electric Propulsion System (AEPS) Hall-effect thrusters for a total engine output fractionally under 50 kW.[33] In 2019, the contract to manufacture the PPE was awarded toMaxar Technologies.[34] After a one-year demonstration period, NASA intended to "exercise a contract option to take over control of the spacecraft".[35] Its expected service time is about 15 years.[36] In late 2023, it was reported that flight qualification testing was occurring on the thrusters for the Power and Propulsion Element.[37]
The Gateway will be deployed in anear-rectilinear halo orbit (NRHO) around the Moon.[38] Theeccentricity of the chosen NRHO takes the station within 1,500 km (930 mi) of thelunar north pole surface at closest approach, and as far away as 70,000 km (43,000 mi) over thelunar south pole, with aperiod of about 7 days.[3][39][40] One of the advantages of an NRHO is the minimal amount of communications blackout with theEarth.
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 lowpolar orbit with aΔv 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 theorbital 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(Δv ≈ 180 m/s) followed by aΔv ≈ 240 m/s NRHO insertion burn to dock with the Gateway as it approaches theapoapsis 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 andΔv ≈ 840 m/s is limited by the capabilities of the Orion life support and propulsion systems.[41]
Gateway will be the firstmodular 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 fromlow 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 supportin-situ resource utilization (ISRU) development and testing from lunar andasteroid sources,[42] and would offer the opportunity for a gradual buildup of capabilities for more complex missions over time.[43]
.png)
For supporting the first crewed mission to the station (Artemis IV) planned for 2028, the Gateway will begin as a minimal space station composed of only two modules: the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO). Both PPE and HALO will be assembled on Earth and launched together on aFalcon Heavy rocket in 2027[1][44] They are expected to reach lunar orbit after nine to ten months.[45] 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.[46] All modules will be connected using theInternational Docking System Standard.[47]
The concept for the Gateway is still evolving, and is intended to include the following modules:[87]
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 announcedSpaceX with its future spacecraftDragon XL as the first commercial partner to deliver supplies to the Gateway (seeGateway Logistics Services).[90]
The first two modules (PPE and HALO) will be launched together on aFalcon Heavy rocket no earlier than 2027.[1][91]
| Year | Mission objective | Mission name | Launch vehicle | Human/robotic elements | Status |
|---|---|---|---|---|---|
| 2027[1] | Launch ofPower and Propulsion Element (PPE) andHabitation and Logistics Outpost (HALO) | Falcon Heavy | Robotic | Under development[92] | |
| September 2028[79] | Delivery of Orion MPCV andI-HAB module[46] | Artemis IV | SLS Block 1B | Crewed | Under development[93][94][95] |
| March 2030[96] | Delivery of Orion MPCV andESPRIT Refueling Module (ERM)[97] | Artemis V | SLS Block 1B | Crewed | Under development[98] |
| March 2031[96] | Delivery of Orion MPCV andCrew and Science Airlock Module | Artemis VI | SLS Block 1B | Crewed | Under development[99] |
| March 2032[96] | (Proposed) Delivery of Orion MPCV and logistics module | Artemis VII | SLS Block 1B | Crewed | Design phase |
NASA officials promote the Gateway as a "reusable command module" that could direct activities on the lunar surface.[100] However, Gateway has received some negative reactions.
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.[100] In a written testimony to Congress, Griffin stated that the current architecture requiring staging operations at a Gateway based in a lunar polarnear-rectilinear 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.[101]
Clive Neal, aUniversity 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".[102]
Former NASA Associate AdministratorDoug Cooke wrote in an article onThe 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".[103]
George Abbey, a former director of NASA'sJohnson 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".[104]
Former NASA astronautTerry W. Virts, who was a pilot ofSTS-130 aboardSpace Shuttle Endeavour and commander of theISS onExpedition 43, wrote in an op-ed onArs 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 "Gemini" before we know what "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". Virts further criticized NASA for abandoning its planned goal of separating crew from cargo, which was put in place following theSpace ShuttleColumbia disaster in 2003.[105]
Apollo 11 astronautBuzz 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 forRobert Zubrin's Moon Direct concept which involves lunar landers traveling from Earth orbit to the lunar surface and back.[106]
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 weightcurrent 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.[107]
Mars Society founder Robert Zubrin called the Gateway "NASA's worst plan yet" in an article in theNational Review. He said, "We do not need a lunar-orbiting station to go to theMoon. We do not need such a station to go toMars. We do not need it to go tonear-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-orbitingInternational Space Station, except to expose human subjects to irradiation – a form of medical research for which a number ofNazi 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".[108]
Retired aerospace engineer Gerald Black wrote in an article onThe 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.[109]
Mark Whittington, a contributor toThe 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 used 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".[110]
AstrophysicistEthan Siegel wrote an article inForbes 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 tolow Earth orbit are twofold: 1. You're outside of theVan 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".[111]
On July 31, 2024, theUnited States Government Accountability Office found that the Gateway has run into technical problems in its communications and propulsion systems which have yet to be addressed by NASA. Its proposed 15-year lifespan is also considered to be too short to properly support a manned mission to Mars.[112][113]
On 10 December 2018, NASA AdministratorJim 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".[114]
Dan Hartman, the program manager for Gateway, on 30 March 2020, toldArs 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.
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 ourLunar 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.[115]
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.The current nominal orbit for the Gateway is a 9:2 synodic resonant southern L2 NRHO
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.Delivery of I-Hab to the Gateway will be via the SLS Block 1B launch vehicle with Orion providing orbital insertion and docking.
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.
{{cite web}}: CS1 maint: url-status (link){{cite web}}: CS1 maint: url-status (link)| Current |  | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Past |
| ||||||||
| Canceled |
| ||||||||
| In development |
| ||||||||
| Proposed | |||||||||
| Concepts | |||||||||
| Related |
| ||||||||
Notes: † Never inhabited due to launch or on-orbit failure, ‡ Part of theAlmaz military program, ° Never inhabited, lacks docking mechanism. | |||||||||
| Missions |
| .svg) | ||||
|---|---|---|---|---|---|---|
| Agencies | ||||||
| Facilities | ||||||
| Rockets | ||||||
| Crewed spacecraft | ||||||
| Robotic spacecraft | ||||||
