Node 4, also known as the Docking Hub System (DHS), was a proposed module of the

International Space Station The International Space Station (ISS) is a large space station that was Assembly of the International Space Station, assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United ...

(ISS). In 2011

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

was considering a 40-month design and development effort for Node 4 that would result in its launch in late 2013. Node 4 would have been built using the Node Structural Test Article (STA) and docked to the forward port of the ''Harmony'' module. The Structural Test Article was built to facilitate testing of ISS hardware and was intended to become Node 1. However, during construction, structural design flaws were discovered. The under-construction Node 2 was renamed Node 1 and the STA (ex-Node 1) was put into storage at the Kennedy Space Center (KSC). Since the

Space Shuttle program The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its ...

was retired, had a decision to build and launch Node 4 been taken, it would have been launched by an

Atlas V Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was developed by Lockheed Martin and has been operated by United Launch Alliance (ULA) since 2006. Primarily used to ...

Delta IV Delta IV was a group of five expendable launch systems in the Delta rocket family. It flew 45 missions from 2002 to 2024. Originally designed by Boeing's Defense, Space and Security division for the Evolved Expendable Launch Vehicle (EELV) p ...

rocket. In December 2011

Boeing The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support s ...

proposed using Node 4 as the core of an

Exploration Gateway Platform The Exploration Gateway Platform was a design concept proposed by Boeing in December 2011 to drastically reduce the cost of Moon, near Earth asteroids (NEAs), or Mars missions by using components already designed to construct a refueling depot an ...

to be constructed at the

ISS The International Space Station (ISS) is a large space station that was assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United States), Roscosmos (Russia), ESA (Europe), ...

and relocated via

space tug ''Space Tug'' is a young adult fiction, young adult science fiction novel by author Murray Leinster. It was published in 1953 in literature, 1953 by Shasta Publishers in an edition of 5,000 copies. It is the second novel in the author's Joe K ...

to an Earth-Moon

Lagrange point In celestial mechanics, the Lagrange points (; also Lagrangian points or libration points) are points of equilibrium for small-mass objects under the gravitational influence of two massive orbiting bodies. Mathematically, this involves t ...

(EML-1 or 2). The purpose of the platform would be to support lunar landing missions with a reusable

lunar lander A lunar lander or Moon lander is a Lander (spacecraft), spacecraft designed to Moon landing, land on the surface of the Moon. As of 2024, the Apollo Lunar Module is the only lunar lander to have ever been used in human spaceflight, completing s ...

after the first two

SLS SLS may refer to the Space Launch System, a launch vehicle developed by NASA. It may also refer to: Education * Stanford Law School, California, U.S. * Sydney Law School, Australia * Symbiosis Law School, India * Same language subtitling, of ...

flights. It would also satisfy the need for a L1

propellant depot An orbital propellant depot is a cache of propellant that is placed in orbit around Earth or another body to allow spacecraft or the transfer stage of the spacecraft to be fueled in space. It is one of the types of space resource depots that ha ...

for lunar missions. Other hardware would include an airlock, an 'international module', and a MPLM based habitat module. In June 2020 the Node STA was moved from the

Space Station Processing Facility The Space Systems Processing Facility (SSPF), originally the Space Station Processing Facility, is a three-story industrial building at Kennedy Space Center for the Manufacturing of the International Space Station, manufacture and Process manufac ...

to the

Shuttle Landing Facility The Shuttle Landing Facility (SLF), also known as Launch and Landing Facility (LLF) , is an airport located on Merritt Island, Florida, Merritt Island in Brevard County, Florida, Brevard County, Florida, United States. It is a part of the Kennedy ...

to make room for commercial partners.

References

{{ISS modules Components of the International Space Station Proposed spacecraft

See also

References