Lunar Gateway Explained

Lunar Gateway should not be confused with Exploration Gateway Platform.

Station:Gateway
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
Station Image Size:300px
Crew:4 maximum (planned)
Launch:2027 (planned)[1]
Launch Pad:Kennedy Space Center Launch Complex 39
Status:In development
Volume:≥ (planned)
Inclination:Polar near-rectilinear halo orbit (NRHO)
Period:≈7 days
Apsis:selene
Insignia:NASA Artemis Gateway logo.png
Insignia Size:200px
Configuration Image:Gateway-infographic-11.16.22.png
Configuration Size:300px
Configuration Caption:Configuration as of 16 November 2022

The Lunar Gateway, or simply Gateway, is a space station which is planned to be assembled in orbit around the Moon. The Gateway is intended to serve as a communication hub, science laboratory, and habitation module for astronauts as part of the Artemis program. It is a multinational collaborative project: participants include NASA, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), the Canadian Space Agency (CSA) and the Mohammed Bin Rashid Space Centre (MBRSC). The Gateway is planned to be the first space station beyond low Earth orbit.[2] [3]

The science disciplines to be studied on the Gateway are expected to include planetary science, astrophysics, Earth observation, heliophysics, fundamental space biology, and human health and performance.[4] As of April 2024 construction is underway of the initial habitation and propulsion modules.[5] [6] 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 Moon, to Mars, and deeper into the Solar System.[7]

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.[8] While the project is led by NASA, the Gateway is meant to be developed, serviced, and used in collaboration with the CSA, ESA, JAXA, and commercial partners. It will serve as the staging point for both robotic and crewed exploration of the lunar south pole and is the proposed staging point for NASA's Deep Space Transport concept for transport to Mars.[9] [10] [11]

Name

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.[12] [13] When the NASA budget was signed into law on February 15, 2019,[14] US$450 million had been committed by Congress to preliminary studies.[14] [15]

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 Tranquility Base as well as concepts for lunar bases have been the main focus of human presence at the Moon.

Studies

An earlier NASA proposal for a cislunar station had been made public in 2012 and was dubbed the Deep Space Habitat. That proposal led to funding in 2015 under the NextSTEP program to study the requirements of deep space habitats.[16] 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.[17] The solar electric Power and Propulsion Element (PPE) of the Gateway was originally a part of the now-canceled Asteroid Redirect Mission.[18]

On 7 November 2017, NASA asked the global science community to submit concepts for scientific studies that could take advantage of the Deep Space Gateway's location in cislunar space. The Deep Space Gateway Concept Science Workshop was held in Denver, Colorado, from 27 February to 1 March 2018. This three-day conference was a workshop where 196 presentations were given for possible scientific studies that could be advanced through the use of the Gateway.[19]

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. The "Lunar Exploration and Access to Polar Regions", from the University of Puerto Rico at Mayagüez, was the winning concept.[20]

In November 2019 NASA unveiled the name and logo of the space station inspired by the American frontier symbol of the St. Louis Gateway Arch.[21]

International participants

On 27 September 2017, an informal joint statement on cooperation regarding the program between NASA and Russia's Roscosmos was announced. However, in October 2020 Dmitry Rogozin, director general of Roscosmos, said that the program is too “U.S.-centric” for Roscosmos to participate in,[22] and in January 2021, Roscosmos announced that it would not participate in the program.[23]

As of January 2024, the Canadian Space Agency (CSA), the European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA) and Mohammed 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 into lunar orbit with some co-manifested with Artemis missions.[24]

Power and propulsion

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 Boeing, Lockheed Martin, Orbital ATK, Sierra Nevada and Space Systems/Loral.[25] These awards are in addition to the ongoing set of NextSTEP-2 awards made in 2016 to study development and make ground prototypes of habitat modules that could be used on the Gateway as well as other commercial applications,[11] so the Gateway is likely to incorporate components developed under NextSTEP as well.[26] The PPE will use four 6 kW BHT-6000 Busek Hall-effect thrusters[27] and three 12 kW NASA/Aerojet Rocketdyne Advanced Electric Propulsion System (AEPS) Hall-effect thrusters for a total engine output fractionally under 50 kW.[28] In 2019, the contract to manufacture the PPE was awarded to Maxar Technologies.[29] After a one-year demonstration period, NASA intended to "exercise a contract option to take over control of the spacecraft".[30] Its expected service time is about 15 years.[31] In late 2023, it was reported that flight qualification testing was occurring on the thrusters for the Power and Propulsion Element.[32]

Orbit and operations

The Gateway will be deployed in a near-rectilinear halo orbit (NRHO) around the Moon.[33] The eccentricity of the chosen NRHO takes the station within of the lunar north pole surface at closest approach, and as far away as over the lunar south pole, with a period of about 7 days.[34] [35] [36] One of the advantages of an NRHO is the minimal amount of communications blackout with the Earth.

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 polar orbit with a Δv of 730 m/s and a half a day of transit time. Orbital station-keeping would require less than 10 m/s of Δv per year, and the orbital inclination could be shifted with a relatively small Δv expenditure, allowing access to most of the lunar surface. Spacecraft launched from Earth would perform a powered flyby of the Moon followed by a NRHO insertion burn to dock with the Gateway as it approaches the apoapsis point of its orbit. The total travel time would be 5 days; the return to Earth would be similar in terms of trip duration and Δv requirement if the spacecraft spends 11 days at the Gateway. The crewed mission duration of 21 days and is limited by the capabilities of the Orion life support and propulsion systems.[37]

Gateway will be the first modular space station to be both human-rated, and autonomously operating most of the time in its early years, as well as being the first deep-space station, far from low Earth orbit. This will be enabled by more sophisticated executive control software than on any prior space station, which will monitor and control all systems. The high-level architecture is provided by the Robotics and Intelligence for Human Spaceflight lab at NASA and implemented at NASA facilities. The Gateway could conceivably also support in-situ resource utilization (ISRU) development and testing from lunar and asteroid sources,[38] and would offer the opportunity for a gradual buildup of capabilities for more complex missions over time.[39]

Structure

For supporting the first crewed mission to the station (Artemis 4) 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 a Falcon Heavy rocket in 2027[40] They are expected to reach lunar orbit after nine to ten months.[41] 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.[42] All modules will be connected using the International Docking System Standard.[43]

Planned modules

Proposed modules

The concept for the Gateway is still evolving, and is intended to include the following modules:[87]

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 SpaceX with its future spacecraft Dragon XL as the first commercial partner to deliver supplies to the Gateway (see Gateway Logistics Services).[90]

Phase 1

The first two modules (PPE and HALO) will be launched together on a Falcon Heavy rocket no earlier than 2027.[91]

YearMission objectiveMission nameLaunch vehicleHuman/robotic elementsStatus
2027Launch of Power and Propulsion Element (PPE) and Habitation and Logistics Outpost (HALO)Falcon HeavyRoboticUnder development[92]
September 2028Delivery of Orion MPCV and I-HAB moduleArtemis 4SLS Block 1BCrewedUnder development[93] [94] [95]
March 2030[96] Delivery of Orion MPCV and ESPRIT Refueling Module (ERM)[97] Artemis 5SLS Block 1BCrewedUnder development[98]
March 2031Delivery of Orion MPCV and Crew and Science Airlock ModuleArtemis 6SLS Block 1BCrewedUnder development[99]
March 2032(Proposed) Delivery of Orion MPCV and logistics moduleArtemis 7SLS Block 1BCrewedDesign phase

Criticism

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. 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.[101]

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".[102]

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".[103]

George Abbey, a former director of NASA's 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".[104]

Former NASA astronaut Terry W. Virts, who was a pilot of STS-130 aboard and commander of the ISS on 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 "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 the Space Shuttle Columbia disaster in 2003.[105]

Apollo 11 astronaut 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 Robert 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 weight 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.[107]

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 Moon. We do not need such a station to go to Mars. We do not need it to go to 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 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".[108]

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.[109]

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 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]

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 low Earth orbit are twofold: 1. You're outside of the 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".[111]

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".[112]

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.

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 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.[113]

External links

Notes and References

  1. Web site: Artemis Programs: NASA Should Document and Communicate Plans to Address Gateway's Mass Risk . . 31 July 2024 . 31 July 2024.
  2. Web site: FY 2022: NASA Budget Request. NASA. 28 May 2021. 1 June 2021.
  3. Web site: Competition Seeks University Concepts for Gateway and Deep Space Exploration Capabilities. Jackson. Shanessa. nasa.gov . NASA. 11 September 2018. 19 September 2018. 17 June 2019. https://web.archive.org/web/20190617064456/https://www.nasa.gov/feature/competition-seeks-university-concepts-for-gateway-and-deep-space-exploration-capabilities/. live.
  4. Web site: Mahoney. Erin. NASA Seeks Ideas for Scientific Activities Near the Moon. nasa.gov. NASA. 24 August 2018. 19 September 2018. 9 June 2019. https://web.archive.org/web/20190609230044/https://www.nasa.gov/feature/nasa-seeks-ideas-for-scientific-activities-near-the-moon/. live.
  5. Web site: РОСКОСМОС – NASA СОВМЕСТНЫЕ ИССЛЕДОВАНИЯ ДАЛЬНЕГО КОСМОСА (ROSCOSMOS – NASA JOINT RESEARCH OF FAR COSMOS) . dead . https://web.archive.org/web/20190910083456/https://www.roscosmos.ru/24136/ . 10 September 2019 . September 29, 2017 . ru.
  6. News: Weitering . Hanneke. NASA and Russia Partner Up for Crewed Deep-Space Missions. Space.com. 27 September 2017. 5 November 2017. 10 September 2019. https://web.archive.org/web/20190910194351/https://www.space.com/38287-nasa-russia-deep-space-gateway-partnership.html. dead.
  7. Web site: NASA. Gateway Memorandum for the Record . nasa.gov. NASA. 2 May 2018. 19 September 2018. 25 July 2019. https://web.archive.org/web/20190725100820/https://www.nasa.gov/sites/default/files/atoms/files/gateway_domestic_and_international_benefits-memo.pdf. live.
  8. Web site: FY 2025 Budget Estimates .
  9. Web site: NASA finally sets goals, missions for SLS – eyes multi-step plan to Mars. Gebhardt. Chris. nasaspaceflight.com. NASASpaceflight. 6 April 2017. 19 September 2018. 21 August 2017. https://web.archive.org/web/20170821221210/https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/. live.
  10. Web site: Hambleton . Kathryn . 28 March 2017 . Deep Space Gateway to Open OpportunitiesArtemis for Distant Destinations . live . https://web.archive.org/web/20170927164237/https://www.nasa.gov/feature/deep-space-gateway-to-open-opportunities-for-distant-destinations/ . 27 September 2017 . April 5, 2017 . nasa.gov . NASA.
  11. Web site: Gatens . Robyn . Crusan . Jason . Cislunar Habitation and Environmental Control and Life Support System . March 31, 2017 . nasa.gov . NASA.
  12. Web site: Some snark (and details!) about NASA's proposed lunar space station. Davis. Jason. The Planetary Society. February 26, 2018. https://web.archive.org/web/20180226175759/http://www.planetary.org/blogs/jason-davis/2018/20180226-lop-g-snark-details.html. February 26, 2018. February 26, 2018.
  13. Web site: Trump's Nasa budget: flying 'Jetson cars' and a return to the Moon. Yuhas. Alan. 2018-02-12. The Guardian. 2018-02-25. 18 July 2019. https://web.archive.org/web/20190718011316/https://www.theguardian.com/science/2018/feb/12/trump-nasa-budget-moon-flying-cars-plans. live.
  14. News: Foust . Jeff . February 17, 2019 . Final fiscal year 2019 budget bill secures $21.5 billion for NASA . April 8, 2023 . Space News.
  15. Web site: NASA just got its best budget in a decade. planetary.org. 27 February 2019. 16 February 2019. https://web.archive.org/web/20190216012055/http://www.planetary.org/blogs/casey-dreier/2019/0215-fy2019-nasa-gets-its-best-budget-in-decades.html. dead.
  16. News: Messier . Doug . August 11, 2016 . A Closer Look at NextSTEP-2 Deep Space Habitat Concepts . dead . https://web.archive.org/web/20180916065822/http://www.parabolicarc.com/2016/08/11/deep-space-habitat-concepts/ . 16 September 2018 . 19 September 2018 . Parabolic Arc.
  17. Web site: Warner. Cheryl. NASA's Lunar Outpost will Extend Human Presence in Deep Space. nasa.gov. NASA. 2 May 2018. 19 September 2018. 25 August 2018. https://web.archive.org/web/20180825033038/https://www.nasa.gov/feature/nasa-s-lunar-outpost-will-extend-human-presence-in-deep-space/. live.
  18. Web site: Foust . Jeff . 2017-07-29 . NASA Seeks Information on Developing Deep Space Gateway Module . 2024-05-08 . Space.com . en.
  19. Web site: Deep Space 2018 Program . Lunar and Planetary Institute. Universities Space Research Association. 27 January 2023.
  20. Web site: Students Blaze New Trails in NASA Space Exploration Design Competition. 21 June 2019. NASA. 5 July 2019.
  21. News: Pearlman . Robert Z. . September 18, 2019 . NASA Reveals New Gateway Logo for Artemis Lunar Orbit Way Station . live . https://web.archive.org/web/20200628112732/https://www.space.com/nasa-lunar-gateway-moon-station-logo.html . 28 June 2020 . 28 June 2020 . space.com.
  22. Web site: Russia skeptical about participating in lunar Gateway. SPACENEWS. 12 October 2020. 25 January 2021.
  23. Web site: 25 January 2021 . "Роскосмос" подтвердил выход из лунного проекта Gateway . 25 January 2021 . ru . Interfax.
  24. Web site: Clark . Stephen . 6 May 2020 . NASA plans to launch first two Gateway elements on same rocket – Spaceflight Now . 25 January 2023 . Space Flight Now . en-US.
  25. Web site: Russell . Jimi . November 2017 . NASA Selects Studies for Gateway Power and Propulsion Element . live . https://web.archive.org/web/20180112203046/https://www.nasa.gov/press-release/nasa-selects-studies-for-gateway-power-and-propulsion-element/ . 12 January 2018 . 2 November 2017 . nasa.gov . NASA.
  26. Web site: Mahoney . Erin . 9 August 2016 . NextSTEP Partners Develop Ground Prototypes to Expand our Knowledge of Deep Space Habitats . live . https://web.archive.org/web/20170410051227/https://www.nasa.gov/feature/nextstep-partnerships-develop-ground-prototypes/ . 10 April 2017 . 6 November 2017 . nasa.gov . NASA.
  27. Maxar and Busek Thruster System for NASA Lunar Gateway Passes Critical Milestone. 2021-04-28. www.prnewswire.com. en.
  28. Web site: Advanced Electric Propulsion System passes full-power test milestone. 15 November 2019. New Atlas.
  29. NASA Awards Artemis Contract for Lunar Gateway Power, Propulsion. NASA. 23 May 2019. 11 December 2019. 20 September 2019. https://web.archive.org/web/20190920171731/https://www.nasa.gov/press-release/nasa-awards-artemis-contract-for-lunar-gateway-power-propulsion/. live.
  30. Web site: Sloss . Philip . 2018-09-11 . NASA updates Lunar Gateway plans . 2024-05-08 . NASASpaceFlight.com . en-US.
  31. Jason Crusan. Gateway Update NASA Advisory Council, Human Exploration and Operations Committee, 7 December 2018
  32. Web site: True Blue: High-Power Propulsion for Gateway – NASA . 2024-03-31 . en-US.
  33. Book: Parrish, Nathan . https://s3-us-west-2.amazonaws.com/advspace.publicshare/NRHO+OD+with+Simulated+DSN.pdf . The current nominal orbit for the Gateway is a 9:2 synodic resonant southern L2 NRHO . Near Rectilinear Halo Orbit Determination with Simulated DSN Observations . AIAA Scitech 2020 Forum . etal . 5 Jan 2020 . American Institute of Aeronautics and Astronautics . 10.2514/6.2020-1700. 978-1-62410-595-1 .
  34. https://phys.org/news/2019-07-angelic-halo-orbit-chosen-humankind.html Angelic halo orbit chosen for humankind's first lunar outpost.
  35. Web site: Szondy . David . 2019-07-19 . Halo orbit selected for Gateway space station . 2024-05-08 . New Atlas . en-US.
  36. News: NASA cubesat to test lunar Gateway orbit. Foust. Jeff. SpaceNews. 16 September 2019. 15 June 2020.
  37. Web site: Whitley. Ryan. Martinez. Roland. Options for Staging Orbits in Cis-Lunar Space . nasa.gov. NASA. 21 October 2015. 19 September 2018. 30 July 2019. https://web.archive.org/web/20190730111818/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150019648.pdf. live.
  38. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20180002054.pdf NASA.gov
  39. https://www.nasa.gov/sites/default/files/atoms/files/march_2017_nac_charts_architecturejmf_rev_3_tagged.pdf NASA.gov
  40. Web site: NASA, Gateway Overview . . 3 May 2024. 8 May 2024.
  41. Web site: Foust. Jeff. NASA refines plans for launching Gateway and other Artemis elements. spacenews.com. SpaceNews. 18 May 2020. 14 May 2020. 16 May 2020. https://archive.today/20200516065402/https://spacenews.com/nasa-refines-plans-for-launching-gateway-and-other-artemis-elements/. live.
  42. Web site: NASA FY 2022 Budget Estimates. Delivery of I-Hab to the Gateway will be via the SLS Block 1B launch vehicle with Orion providing orbital insertion and docking. . PDF page 97, in-text page DEXP-67 .
  43. Web site: Patel . Neel V. . 2017-04-04 . NASA Unveils Deep Space Gateway and Transport Architectures . 2024-05-08 . Inverse . en.
  44. Web site: JPL Seeks Robotic Spacecraft Development for Asteroid Redirect Mission. Greicius. Tony . 2016-09-20. NASA. 30 May 2019. 17 June 2019. https://web.archive.org/web/20190617075954/https://www.nasa.gov/feature/jpl/jpl-seeks-robotic-spacecraft-development-for-asteroid-redirect-mission/. live.
  45. Web site: NASA closing out Asteroid Redirect Mission. 2017-06-14. SpaceNews. 30 May 2019.
  46. Web site: Asteroid Redirect Robotic Mission. jpl.nasa.gov. NASA. 30 May 2019. 30 May 2019 . https://web.archive.org/web/20190530113407/https://www.jpl.nasa.gov/missions/asteroid-redirect-robotic-mission-arrm/. live.
  47. Web site: Deep Space Gateway and Transport: Concepts for Mars, Moon Exploration Unveiled. 4 April 2017 . Science News. 2019-05-30. 30 May 2019. https://web.archive.org/web/20190530113409/http://www.sci-news.com/space/deep-space-gateway-transport-mars-moon-exploration-04756.html. live.
  48. Web site: NASA chooses Maxar to build keystone module for lunar Gateway station. Clark . Stephen. Spaceflight Now. 2019-05-30. 5 June 2019. https://web.archive.org/web/20190605140715/https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/. live.
  49. Web site: Boyle. Alan. NASA says Maxar will build the first big piece for Gateway station in lunar orbit. GeekWire. 23 May 2019. 28 August 2023.
  50. Web site: Foust. Jeff . NASA issues study contracts for Deep Space Gateway element. SpaceNews. 3 November 2017. 11 December 2019.
  51. Web site: Gebhardt . Chris . 6 April 2017 . NASA finally sets goals, missions for SLS – eyes multi-step plan to Mars . live . https://web.archive.org/web/20170821221210/https://www.nasaspaceflight.com/2017/04/nasa-goals-missions-sls-eyes-multi-step-mars/ . 21 August 2017 . April 9, 2017 . NASASpaceFlight.com.
  52. News: Foust. Jeff. NASA selects Maxar to build first Gateway element. May 23, 2019. SpaceNews. May 23, 2019.
  53. R. Joseph Cassady, Sam Wiley, Jerry Jackson. Status of Advanced Electric Propulsion Systems for Exploration Missions. . Aerojet Rocketdyne, October 2018.
  54. News: Clark. Stephen. NASA chooses Maxar to build keystone module for lunar Gateway station . Spaceflight Now. May 24, 2019. 13 July 2019. 5 June 2019 . https://web.archive.org/web/20190605140715/https://spaceflightnow.com/2019/05/24/nasa-chooses-maxar-to-build-keystone-module-for-lunar-gateway-station/. live.
  55. Web site: NASA Awards Contract to Launch Initial Elements for Lunar Outpost . . 9 February 2021 . 9 February 2021.
  56. Web site: Foust. Jeff. ISS partners endorse modified Gateway plans. SpaceNews. 30 August 2019. 11 December 2019.
  57. 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.
  58. Web site: Planetary Society. Humans in Deep Space. planetary.org. 6 August 2019. 17 November 2019. https://web.archive.org/web/20191117234651/https://www.planetary.org/explore/space-topics/space-missions/humans-in-deep-space.html. live.
  59. Web site: Foust. Jeff. NASA to sole source Gateway habitation module to Northrop Grumman. SpaceNews. 23 July 2019. 11 December 2019.
  60. Web site: Justification for other than full and open competition (JOFOC) for the Minimal Habitation Module (MHM). Federal Business Opportunities. 23 July 2019. Solicitation 80JSC019GTWYHAB. 3 September 2019. https://web.archive.org/web/20190903173343/https://www.fbo.gov/index.php?tab=documents&tabmode=form&subtab=core&tabid=d4e9e11d78e9dd0b8bd05395b3d82c7f. live.
  61. Web site: Gebhardt. Chris. Northrop Grumman outlines HALO plans for Gateway's central module. 7 August 2020. NASASpaceFlight.com. 13 August 2020. 10 August 2020. https://web.archive.org/web/20200810151335/https://www.nasaspaceflight.com/2020/08/northrop-halo-plans-gateway/. live.
  62. Web site: Messier. Doug. NASA Awards Contract to Northrop Grumman for Gateway Habitat Module. Parabolic Arc. 23 July 2019. 11 December 2019. 29 July 2019. https://web.archive.org/web/20190729005145/http://www.parabolicarc.com/2019/07/23/nasa-awards-contract-to-northrop-grumman-for-lunar-gateway-habitat-module/. dead.
  63. Web site: Evans . Ben . 2021-07-10 . NASA, Northrop Grumman Finalize Lunar Gateway Integration Contract. 2023-08-11 . AmericaSpace . en-US.
  64. Web site: NASA signs Gateway habitat design contract with Northrop Grumman. Spaceflight Now. 9 June 2020. 10 June 2020. 10 June 2020. https://web.archive.org/web/20200610222822/https://spaceflightnow.com/2020/06/09/nasa-signs-gateway-habitat-design-contract-with-northrop-grumman/. live.
  65. Web site: Werner . Debra . 2022-07-18 . Northrop Grumman taps Solstar for HALO Module Wi-Fi . 2023-01-13 . SpaceNews . en-US.
  66. Web site: NM firm builds Wi-Fi 'hotspot' for NASA moon station . 2023-01-13 . news.yahoo.com . 3 August 2022 . en-US.
  67. Web site: A Home for Astronauts around the Moon – NASA . 2024-04-03 . en-US.
  68. Web site: NASA updates lunar Gateway plans. September 11, 2018. Philip. Sloss. NASASpaceFlight.com. 15 September 2018. 6 August 2019. https://web.archive.org/web/20190806063256/https://www.nasaspaceflight.com/2018/09/nasa-lunar-gateway-plans/. live.
  69. Anatoly Zak. ESA develops logistics vehicle for cis-lunar outpost . RussianSpaceWeb.com, 8 September 2018.
  70. 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
  71. Web site: Back to the Moon, a step towards future exploration missions. 5 August 2019 . 7 August 2020. 22 October 2020. https://web.archive.org/web/20201022063112/https://www.thalesgroup.com/fr/monde-espace/orbital-infrastructure-and-space-transport/magazine/retour-lune-pas-vers-nouvelles. live.
  72. Jeff Foust. Funding Europe's space ambitions . The Space Review, December 2019.
  73. Kerry Hebden. Hera mission is approved as ESA receives biggest ever budget . Room, 29 November 2019.
  74. News: Europe steps up contributions to Artemis Moon plan. BBC News. 2020-10-14. 14 October 2020. 14 October 2020. https://web.archive.org/web/20201014104207/https://www.bbc.com/news/science-environment-54537906. live.
  75. Web site: Thales Alenia Space on its way to reach the Moon . thalesgroup.com. 14 October 2020 . 14 October 2020.
  76. Web site: Thales Alenia Space: at the heart of lunar industrial challenges. Thales Group. 7 January 2021 .
  77. Web site: Gateway: Lunar Link . 2024-06-26 . www.esa.int . en.
  78. Web site: Gateway: Lunar View . 2024-06-26 . www.esa.int . en.
  79. Web site: Gateway: Lunar I-Hab . 2024-06-26 . www.esa.int . en.
  80. Web site: Foust . Jeff . NASA planning to spend up to $1 billion on space station deorbit module . . 13 March 2023 . 13 March 2023.
  81. Web site: Artemis IV . . 26 August 2023.
  82. Web site: Agency . Canadian Space . 2020-06-26 . About Canadarm3 . 2023-09-19 . Canadian Space Agency.
  83. Web site: Canadian Space Agency . 26 June 2020 . Building the next Canadarm . Government of Canada.
  84. News: 8 December 2020 . Canadian Space Agency awards Canadarm3 contract worth $22.8 million to MDA . CTV News . The Canadian Press .
  85. News: MDA . 8 December 2020 . MDA Announces Contract for Canadarm3 on NASA-led Gateway . Yahoo News . CNW . dead . 17 December 2020 . https://web.archive.org/web/20210428040544/https://www.yahoo.com/now/mda-announces-contract-canadarm3-nasa-143000109.html . 28 April 2021.
  86. Web site: Foust . Jeff . UAE to build airlock for lunar Gateway . . 7 January 2024 . 7 January 2024.
  87. Web site: Future Human Exploration Planning:Lunar Orbital Platform – Gateway and Science Workshop Findings. Cursan. Jason. March 27, 2018. 13 April 2018. 1 June 2019. https://web.archive.org/web/20190601195248/https://www.nasa.gov/sites/default/files/atoms/files/20180327-crusan-nac-heoc-v8.pdf. live.
  88. News: Canada's heading to the moon: A look at the Gateway . Mortillaro. Nicole. CBC News. February 28, 2019. 2 March 2019. 2 March 2019. https://web.archive.org/web/20190302004136/https://www.cbc.ca/news/technology/canada-lunar-gateway-1.5037522. live.
  89. News: Canadian Space Agency to build robotic arms for lunar space station. Global News. 29 September 2017. 29 September 2017. https://web.archive.org/web/20170929130437/https://globalnews.ca/news/3775926/canadian-space-agency-robotic-arms/. live.
  90. Web site: Foust . Jeff . SpaceX wins NASA commercial cargo contract for lunar Gateway . . 27 March 2020 . 27 March 2020.
  91. Web site: Sloss . Philip . 2024-05-23 . Initial Gateway elements beginning systems integration while NASA works on a launch date . 2024-05-24 . NASASpaceFlight.com . en-US.
  92. Web site: PHOTO OF THE DAY: NASA Highlights the Gateway Space Station's HALO Module - Space Coast Daily . 2024-04-18 . spacecoastdaily.com.
  93. Web site: Lunar I-Hab mock-up all set . 2024-04-18 . www.esa.int . en.
  94. Web site: 4 April 2024 . On 4-4-24, we've got 4 photos for you for Artemis IV! .
  95. Web site: 2024-04-30 . Gateway: Forward Progress on Artemis IV - NASA . 2024-05-01 . en-US.
  96. Web site: FY 2025 Budget Request FY 2025 President's Budget Request Moon to Mars Manifest . 6 . . 15 April 2024 . 31 July 2024.
  97. Web site: Foust . Jeff . NASA foresees gap in lunar landings after Artemis 3 . . 20 January 2022 . 6 February 2022.
  98. Web site: Gateway: Lunar View . 2024-04-18 . www.esa.int . en.
  99. Web site: 2024-01-22 . UAE starts historic Lunar Gateway project . 2024-05-05 . SatellitePro ME . en-US.
  100. Web site: Foust . Jeff . 2018-12-25 . Is the Gateway the right way to the moon? . 2024-05-08 . SpaceNews . en-US.
  101. Web site: Griffin. Michael. Returning to the Moon: Keeping Artemis on Track. 17 January 2024. 19 January 2024.
  102. Web site: Berger. Eric. Eric Berger (meteorologist). We got a leaked look at NASA's future Moon missions—and likely delays. Ars Technica. 20 June 2022. 27 June 2020.
  103. Web site: Cooke. Doug. Getting back to the moon requires speed and simplicity . The Hill. 13 September 2019. 20 September 2019. 20 September 2019. https://web.archive.org/web/20190920121323/https://thehill.com/opinion/technology/461299-getting-back-to-the-moon-requires-speed-and-simplicity. live.
  104. News: Abbey . George . 13 July 2019 . The Moon is "a God-given space station orbiting Earth" [Opinion] ]. live . https://web.archive.org/web/20190920155132/https://www.houstonchronicle.com/opinion/outlook/article/The-moon-is-a-God-given-space-station-orbiting-14092345.php . 20 September 2019 . 20 September 2019 . en-us . Houston, Texas . Houston Chronicle.
  105. Web site: Op-ed: The Deep Space Gateway would shackle human exploration, not enable it. 28 September 2017. Ars Technica. 20 May 2018. 21 May 2018. 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/. live.
  106. Web site: Advisory group skeptical of NASA lunar exploration plans. Foust. Jeff. 16 November 2018. SpaceNews. 20 December 2018.
  107. Web site: Pultarova . Tereza . 2023-01-08 . NASA's moon-orbiting space station will be claustrophobic, architect says . 2023-04-04 . Space.com . en.
  108. Web site: NASA's Worst Plan Yet. 16 May 2017 . National Review. 20 May 2018. 2 March 2018. https://web.archive.org/web/20180302014801/https://www.nationalreview.com/2017/05/nasa-lunar-orbit-space-station-terrible-idea/. live.
  109. Gerald Black. The Lunar Orbital Platform – Gateway: an unneeded and costly diversion . The Space Review, 14 May 2018.
  110. Web site: Whittington. Mark. NASA's unnecessary US$504 million lunar orbit project doesn't help us get back to the Moon. The Hill. 16 June 2018. 20 December 2018. 14 November 2019. https://web.archive.org/web/20191114223317/https://thehill.com/opinion/technology/392611-nasas-unnecessary-504-million-lunar-orbit-project-doesnt-help-us-get-back. live.
  111. Web site: Siegel. Ethan. NASA's Idea For A Space Station In Lunar Orbit Takes Humanity Nowhere. Forbes. 15 February 2019. 16 February 2019. 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. live.
  112. Web site: spacenews.com. 15 December 2018. Is the Gateway the right way to the moon?. Jeff. Foust. 20 August 2019.
  113. Web site: Eric. Berger. NASA officials outline plans for building a lunar Gateway in the mid-2020s. Ars Technica. 30 March 2020. 25 April 2020. 13 May 2020. 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/. live.