How NASA Plans To Build The First Moon Space Station
By now, multiple Gateway station segments are nearing completion in preparation for launch. With NASA planning to return to the Moon and for good, Gateway is supposed to play a crucial role in facilitating future Artemis missions. However, this brings up the question of what progress has been made and when will it be complete.
Gateway is a joint effort between NASA and a few other agencies. On top of that, contributors such as NASA have contracted some of the work out to Northrop Grumman among other companies. Everyone involved has either a dedicated module, or some sort of addition. All of which need to work together and be ready by a set time if the station wants to be fully operational in the coming years.
Currently, if everything stays on schedule, between 2024 and 2031, the Gateway lunar space station will be built out and then complete, ready to transfer astronauts and supplies from the lunar surface to Earth and back. Here I will go more in-depth into the future timeline of Gateway, recent progress that’s been made, what to expect in the coming weeks, and more.
Timeline & Progress
The four main agencies working together on this project include NASA, the European Space Agency, the Canadian Space Agency, and the Japan Aerospace Exploration Agency. NASA is responsible for the two primary initial modules the Power and Propulsion Element (PPE) and the Habitation and Logistics Outpost (HALO). PPE was contracted to Maxar Technologies while HALO was contracted to Northrop Grumman, with additions from JAXA in the form of batteries. Scheduled in late 2024, these two modules will launch together and begin the Gateway Station’s operational life. In 2021, NASA selected SpaceX and the Falcon Heavy to launch both of these segments together.
With these two segments scheduled to launch first, they are the furthest ahead in terms of progress. Just last month, Northrop Grumman tweeted saying, “Our new thermal vacuum chamber at our Gilbert, AZ satellite manufacturing facility has started construction! Built to test our largest spacecraft such as HALO for the @NASA_Gateway.” As HALO and PPE get closer to launch, they will soon begin going through final testing to make sure they are ready for the journey. Once these two modules are orbiting the Moon, it will be at least a few years before they are added to with additional hardware.
Specifically, about three to four years after HALO and PPE are launched, two more modules will join them. The first will be International Habitat (I-HAB) which is one of two primary contributions of the ESA. The I-Hab is a pressurized module that will provide living quarters for astronauts visiting the Gateway, including multiple docking ports for berthing vehicles as well as other modules. Back in October 2020, ESA signed an agreement with NASA to contribute habitation and refueling modules, enhanced lunar communications to the Gateway, and two more Orion Service Modules. The module will launch on an SLS Block 1B variant. Assuming everything stays on schedule, one year after this third module docks to Gateway, the fourth module will launch.
In 2029 or 5 years after the initial Gateway segments were launched, the ESPRIT Refueling Module (ERM) will begin its journey to the Moon. This module is the other ESA contribution and will expand the gateway station to a four-module lunar post. Similar to the previous module, this segment will also launch on the SLS Block 1B Variant. As of right now, this fourth and final module is the last confirmed segment for the Gateway station. This being said, there are a few proposed additions that we could see in the coming years. This includes logistics modules, airlock additions, and other segments between 2030, and 2031.
While the CSA and JAXA aren’t necessarily providing their own modules, they have responsibilities throughout the Gateway timeline. For example, Canada will provide Canadarm3, a large robotic arm. Canadarm3 will move end-over-end to reach many parts of Gateway’s exterior, where its anchoring “hand” will plug into specially designed interfaces. The CSA also will provide robotic interfaces for Gateway modules, which will enable payload installation including that of the first two scientific instruments launching on the inaugural Gateway elements. JAXA is meant to play a supporting role with additions to the I-HAB module including environmental control and life support system, batteries, thermal control, and imagery components, which will be integrated into the module by ESA prior to launch. If everything goes according to plan, between 2024 and 2029, the Gateway space station will launch multiple missions and form the first lunar space station.
Gateway Station
Relative to the International Space Station, Gateway will be a small, human-tended space station orbiting the Moon that will provide extensive capabilities to support NASA’s Artemis campaign. The purpose of this station is to provide docking ports for a variety of visiting spacecraft, space for crew to live and work, and on-board science investigations to study heliophysics, human health, and life sciences, among other areas.
On a future mission, we can expect a transfer using Gateway from one spacecraft to another. First SLS will launch with a crew aboard the Orion Spacecraft. NASA selected SpaceX to provide the human landing system that will transport Artemis III astronauts from Orion in lunar orbit to the surface of the Moon and back again. SpaceX plans to use a unique concept of operations to increase the overall efficiency of their lander. After a series of tests, SpaceX will fly at least one uncrewed demo mission that lands Starship on the lunar surface. When Starship has met all of NASA’s requirements and high standards for crew safety, it will be ready for its first Artemis mission. On an actual mission, both the lunar Starship and Orion spacecraft will dock to Gateway. The crew will then transfer from Orion to Starship, land on the Moon, then come back up and transfer back to Orion for the trip back. Both of which use the Gateway station as a hub.
Specifically, before the crew launch, SpaceX will launch a storage depot to Earth orbit. A series of reusable tankers will carry propellant to the storage depot to fuel the human landing system. The uncrewed Starship human landing system will then launch to Earth orbit and rendezvous with the storage depot to fill its tanks before executing a translunar injection engine burn and traveling approximately six days to NRHO where it will await the crew.
One of the most important parts of the Gateway station and part of the reason the South Lunar Pole becomes so accessible with it has to do with its orbit. Decades ago during the Apollo missions, NASA was very limited in its options for landing sites on the Moon. Gateway is supposed to help fix that problem and provide access to the entire Moon.
When NASA was originally planning the best orbit for Gateway, they first looked at two different options that had their respective pros and cons. The first was a low lunar orbit. A spacecraft in low lunar orbit follows a circular or elliptical path very close to the lunar surface, completing an orbit every two hours. Transit between Gateway and the lunar surface would be quite simple in a low lunar orbit given their proximity, but because of the Moon’s gravity, more propellant is required to maintain the orbit. Therefore, low lunar orbit is not very efficient for Gateway’s planned long-term presence at the Moon – at least 15 years.
The other consideration was a distant retrograde orbit, which provides a large, circular, and stable (or more fuel-efficient) orbit that circles the Moon every two weeks. However, what Gateway would gain in a stable orbit, it would lose in easy access to the Moon: the distant orbit would make it harder to get to the lunar surface.
This is when NASA began looking into a third option, NRHO. NRHO stands for Near Rectilinear Halo Orbit and is just right for Gateway, marrying the upsides of low lunar orbit (surface access) with the benefits of distant retrograde orbit (fuel efficiency). Hanging almost like a necklace from the Moon, NRHO is a one-week orbit that is balanced between the Earth’s and Moon’s gravity. This orbit will periodically bring Gateway close enough to the lunar surface to provide simple access to the Moon’s South Pole where astronauts will test capabilities for living on other planetary bodies, including Mars. NRHO can also provide astronauts and their spacecraft with access to other landing sites around the Moon in addition to the South Pole.
The benefits of NRHO don’t end with surface access and fuel efficiency. NRHO will allow scientists to take advantage of the deep space environment for a new era of radiation experiments that are meant to facilitate a greater understanding of potential impacts of space weather on people and instruments. NRHO will also give Gateway a continuous line of sight, or “view”, of Earth, translating to uninterrupted communication between Earth and the Moon. As NASA gets closer to the first launch of HALO and PPE, we can watch as the station comes together over the following years in support of the Artemis program.
Conclusion
NASA and its 3 main partners are all working on their respective contributions to the Gateway space station. NASA is working on the two initial segments scheduled to launch in late 2025. Not long after the ERM and I-HAB modules will launch and expand the station and its capabilities. We will have to wait and see how it progresses and the impact it has on the space industry.
