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First human outpost near the Moon

After several years of behind-the-scene negotiations, the partners in the International Space Station, ISS, project are quietly putting the finishing touches on a grand plan to extend human presence beyond the Earth's orbit for the first time since 1972 and to establish a pioneering long-term outpost in the vicinity of the Moon, known as Deep Space Gateway, DSG. If this effort manages to overcome all the financial, political and technical hurdles, it might lead to even more ambitious human undertakings in deep space, including a return to the Moon, visits to asteroids and, ultimately, an expedition to Mars! This page is designed to serve as a starting point for our exclusive unofficial coverage and visualization of the project in the coming years.

Read our introductory articles on the subject at: and Popular Mechanics


Main components of the Deep Space Gateway and their known features at a glance as of October 2017:

Solar panel power supply capability
65-70 kilowatt at the start of the mission
Electric thruster capability
26.6 kilowatts for operations
Number of engines and their power
Four 13.3-kilowatt, one 15-20 kilowatt
Xenon fuel load
Around 1,200 kilograms
Hydrazine fuel load
400 kilograms
Xenon propellant load
From 400 to 1,000 kilograms
Hydrazine fuel load
From 1,000 to 400 kilograms
Key current feature
Science airlock
Key current function
Communications with the lunar surface
Total pressurized volume
76 cubic meters
Number of docking ports
Two radial and two axial ports
Life-support system
Open loop
Crew support capability
30 days in lunar orbit
Two isolated chambers allowing emergency ingress
Spacesuit support
Russian and US suits are available for backup
Docking ports
One zenith (sky-facing) and one axial (station facing) port
Crew chamber
Nadir (station-facing) compartment
Logistics Module
Launch mode
Either co-manifested with the SLS rocket or launched on a smaller rocket
Cargo capacity inside pressurized module
4,200 kilograms (when launched on SLS) or 2,500 kilograms
Unpressurized cargo capacity
1,175 kilograms
End of mission mode
Robotic lunar lander
Ascent stage
Reusable stage
Descent stage
Main mission
Lunar sample return


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Origin of the lunar orbital station concept

The concept of an orbital station around the Moon appeared in early American and Soviet studies of lunar exploration. Around 1959, Wernher von Braun envisioned the refueling of transport ships in the lunar orbit. In 1962, Sergei Korolev, the founder of the Soviet space program, considered long-duration "satellite-stations" in lunar orbit to support deep-space expeditions.


Cis-lunar stations near Lagrangian points

At the beginning of the 21st century, or some 240 years after their discovery, Lagrangian points in the Earth-Moon system appeared for the first time on the short list of destinations for manned spacecraft. In its official strategy made public in 2011, NASA said that "initially, exploring the vast expanse of space surrounding the Earth and Moon, including the Lagrange points, will establish a human presence outside of the low Earth orbit...


How it all started

Although at the beginning of the 2010s, NASA proclaimed an expedition to Mars as the ultimate goal of its human space flight program, the US agency agreed with its ISS partners that the road to the Red Planet would go through an outpost in the cis-lunar space.


NEW, Oct. 18: Deep Space Gateway in 2017

During 2017, the concept of the cis-lunar station made major strides toward leaving a drawing board. In October, US Vice President Mike Pence seemingly came very close to endorsing the project in a major space policy announcement.


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How would it work? A multitude of designs and missions

In 2011, the US embarked on the full-scale development of the super heavy booster dubbed the Space Launch System, SLS. The giant rocket would be powerful enough to send around 10 tons of extra cargo along with the Orion crew vehicle beyond the Earth's orbit. As result, each Orion mission could carry a building block of the future outpost to the lunar orbit.


What is it for? To the Moon and beyond

Paradoxically, for NASA, the main goal of the near-lunar station is not the Moon itself, but testing technologies for a trip to Mars. For example, the station could be a place for an endurance test of a closed-loop life-support system, later needed for a Mars mission. Radiation protection and propulsion systems could also be tested. Still, other partners in the project could use the outpost to explore the Moon itself.


Where would it be? Orbital mechanics

After initial plans to place the near-lunar station in the Earth-Moon Lagrangian points, engineers began leaning toward more exotic near-lunar trajectories known as Lunar Distant Retrograde Orbit, LDRO, and Near Rectilinear Orbit, NRO.


Power and Propulsion Bus, PPB

The assembly of the human outpost in lunar orbit will begin with the Power and Propulsion Bus, responsible for the maneuvering, power and communications on the future habitat. For the first time in human missions, the module will feature ion thrusters. One day, they could be used for a mission to Mars, making the spacecraft a critical test bed for the future.


UPDATE, Oct. 20: ESPRIT module

A dramatic re-write of the assembly schedule for the Deep Space Gateway at the beginning of 2017 has put severe mass restrictions on the first component of the cis-lunar outpost. To resolve the problem, the international team of experts considered various solutions, including in-flight refueling. According to European engineers, a newly designed robotic vehicle could save the day by taking some of the tasks of the original Power and Propulsion Bus.


Robotic arm

Capitalizing on its extensive experience in the Space Shuttle and the ISS programs, the Canadian Space Agency promised to provide a sophisticated robotic arm for the cis-lunar base. The device was expected to ride into space, strapped to the very first piece of the outpost -- the propulsion module.


Habitation modules

From the outset of the project, the partners agreed to build at least two habitation modules for the crew of the cis-lunar outpost. Not surprisingly, the European Space Agency, ESA, took responsibility to provide the modules, based on Europe's experience in the Columbus and Spacelab programs.


Japanese mini-hab

In 2016, Japan offered to contribute a small habitation module, which would sport a closed-loop life-support system, tasked with recycling water and oxygen and thus reducing the need for supplies from Earth. The module would be based on Japan's cargo ship developed for the International Space Station.


Russian airlock module

By June 2016, Russia limited its role in the cis-lunar project to an airlock module, whose concept was formulated at the nation's key human space flight contractor, RKK Energia, by October of the same year. During its flight to the lunar vicinity either on NASA's SLS or on Russia's own Angara-5/KVTK rocket, the module would double as a cargo vehicle. It could also host the US space suits along with the Russian Orlans.

Big hab

Deep-Space Transport, DST

In the second phase of the assembly at the end of the 2020s, NASA hopes to equip the cis-lunar platform with a bigger better habitation and propulsion module, which would be capable of deep-space missions, possibly even to the vicinity of Mars. It will generate up to 150 kilowatts of power and feature the latest electric propulsion system.


Robotic lunar lander, HLEPP

The cis-lunar outpost is also expected to serve as a home and, possibly, a mission control center for a robotic lunar lander designed to collect and return soil samples from the surface of the Moon. As of 2016, European, Japanese and Canadian space agencies hoped to pool funding to build the rover-carrying unmanned platform for the project, known as the Human Lunar Exploration Precursor Program, HLEPP.


Manned lunar lander

If money allows, the various agencies could cooperate on the development of a manned lander designed for sorties onto the lunar surface. However, the jury is still out on the efficiency of deploying a non-reusable lander at the station, versus flying independent expeditions to the Moon without a way station. Unlike most agencies, NASA is skeptical about the whole idea, because it would take the focus away from Mars.


NEW, Nov. 1: Russian Lunar Mission Support Module

The Russian political decision in the summer of 2017 to participate in the development of the DSG project, prompted engineers to consider again possible Russian contributions to the project. One concept prepared for the Checkpoint Review meeting in October 2017 included a Lunar Mission Support Module.


Orion transport spacecraft

The first and only vehicle capable of delivering astronauts to the outpost (at least initially) will be NASA's Orion spacecraft launched on the giant SLS rocket. Most of the station's components will hitchhike to the lunar vicinity along with the Orion. By the time, it carries its first crew, NASA will have spent nearly two decades for the Orion's development.


PTK/Federatsiya spacecraft

As of 2016, Roskosmos promised that its new-generation transport spacecraft, PTK NP/Federatsiya will have a rocket large enough to send it beyond the low Earth orbit around 2027. If ever built, the PTK will provide an alternative to the Orion for astronauts and cosmonauts to reach the cis-lunar base.


Logistics and cargo ships

Various concepts of unmanned vehicles carrying cargo to the cis-lunar outpost have been under consideration in the past couple of years. Cargo flights would be required to extend the presence of the crews on the outpost beyond the few days afforded by the life-support system of the manned spacecraft.


NASA's SLS rocket

NASA's super-heavy rocket known as the Space Launch System or SLS was approved for development in 2011 and it is promised to be ready for the first test launch at the end of 2019. SLS derived from the Ares-5 rocket, first envisioned around 2003.


Russian super-heavy rocket

In 2016, the Russian space officials concluded that a super-heavy launcher would be the only efficient way for carrying crews to the Moon. However, with all the economic problems facing the Russian economy, the big rocket is not expected to appear on the scene until the late 2020s.


Russian launchers: Proton and Angara-5/KVTK

Although the key mission for the Angara-5V rocket would be to compete on the commercial market and deliver the heaviest military payloads, the rocket could fins some role in human missions beyond the Earth's orbit. As many as four Angara-5Vs would be required to put a crew on the lunar surface with the use of the 20-ton next-generation PTK NP spacecraft and a separately launched lander.

All articles and illustrations inside this section by Anatoly Zak unless stated otherwise. All rights reserved

Last update: November 14, 2017