Node 2

''Harmony'', also known as ''Node 2'', is the "utility hub" of the International Space Station. It connects the laboratory modules of the United States, Europe and Japan, as well as providing electrical power and electronic data. Sleeping cabins for four of the crew are housed here.

''Harmony'' was successfully launched into space aboard Space Shuttle flight STS-120 on 23 October 2007. After temporarily being attached to the port side of the ''Unity'' module, it was moved to its permanent location on the forward end of the ''Destiny'' module on 14 November 2007. ''Harmony'' added to the station's living volume, an increase of almost 20%, from to . Its successful installation meant that from NASA's perspective, the station was considered to be "U.S. Core Complete".

Origin of name

The unit formerly known as ''Node 2'' was renamed ''Harmony'' in March 2004. The name was chosen in a competition where more than 2,200 students from 32 states participated. The ''Node 2 Challenge'' required students to learn about the space station, build a scale model, and write an essay explaining their proposed name for the module, which will serve as a central hub for science labs. The six winning classes were: Paul Cummins' 8th grade class at Browne Academy, Alexandria, Va.; Sue Wilson's 3rd grade class at Buchanan Elementary School, Baton Rouge, La.; Brigette Berry's 8th grade class at League City Intermediate School, League City, Texas; Bradley Neu's 9th grade science class at Lubbock High School, Lubbock, Texas; Russell Yocum 's 3rd grade class at West Navarre Intermediate School, Navarre, Fla.; and, David Dexheimer's students at the World Group Home School, Monona, Wisconsin.

Specifications

''Harmony'' is the second of three node modules on the United States Orbital Segment (USOS). It is composed of a cylindrical, thick 2219-T851 aluminium alloy pressure shell with two endcones and is thermally insulated by a goldised Kapton blanket. It is protected from micrometeoroids by 98 panels, each made from a composite sandwich of stainless steel and 6061-T6 aluminium alloy, and a secondary barrier of Kevlar/resin. The design is based on the existing Multi-Purpose Logistics Module, as well as the European Space Agency's ''Columbus'' module (both of which have only one passive Common Berthing Mechanism BM. There are six CBMs on ''Harmony'': the aft CBM that connects it to ''Destiny'' is passive; the rest are active.

''Harmony'' is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. Its deployment expanded the Space Station, allowing it to grow from the size of a three-bedroom house, to the space equivalent of a typical five-bedroom house, once the Japanese '' Kibō'' and European ''Columbus'' laboratories are attached. The Space Station robotic arm, Canadarm2, is able to operate from a powered grapple fixture on the exterior of ''Harmony''. ''Harmony'' is equipped with eight International Standard Payload Racks: four avionics racks and four for stowage or crew quarters. The first two were delivered on STS-126 and the second two on STS-128. After the cancellation of the Habitation Module, ''Harmony'' was chosen to house the American Crew Quarters.

Construction agreement

In an agreement between NASA and the European Space Agency, the company Thales Alenia Space, built ''Harmony'' at its facility in Turin, Italy. ''Harmony'' arrived on 1 June 2003 at the Kennedy Space Center in Florida after its flight in an Airbus Beluga oversize cargo vehicle. Following post transportation inspection, the Italian Space Agency (ASI) formally handed over ''Harmony'' to the European Space Agency (ESA). From there, ESA formally transferred ownership of ''Harmony'' to NASA on 18 June 2003, taking place in the Space Station Processing Facility (SSPF) of the Kennedy Space Center. The handover of ''Harmony'' completed a major element of the barter agreement, between ESA and NASA, that was signed in Turin, Italy on 8 October 1997.

Paolo Nespoli, an ESA astronaut born in Milan, Italy, accompanied the ''Harmony'' module aboard STS-120 as a mission specialist.

Launch

''Harmony'' was launched on 23 October 2007 aboard of the STS-120, as the primary component of assembly mission ISS-10A.

On 26 October 2007, the station's Space Station Remote Manipulator System (SSRMS) removed ''Harmony'' from the shuttle cargo bay and temporarily mated it to the port side of ''Unity'' and, on 27 October 2007, the crew entered in ''Harmony''. After the Space Shuttle was departed, ''Harmony'' was relocated to the forward dock of the ''Destiny'' laboratory. It required three EVAs by the station crew to complete the installation.

Connecting modules and visiting vehicles

''Harmony'' was the first permanent living space enlargement to the ISS after the ''Pirs'' docking compartment was added in 2001. The Expedition 16 crew moved the Pressurized Mating Adapter (PMA-2) on 12 November 2007 from ''Destiny'' to the forward berth of ''Harmony''. The combined PMA-2/''Harmony'' unit was subsequently berthed to its final destination at the forward end of ''Destiny'' on 14 November 2007. All the following Space Shuttle missions would dock at this location.

On 11 February 2008, ESA's ''Columbus'' laboratory was attached to the starboard hatch of the ''Harmony'' module during space shuttle mission STS-122. On 14 March 2008, the Experiment Logistics Module Pressurized Section (ELM-PS) of Kibō was attached to its interim location: the zenith hatch of ''Harmony''. During STS-124, a Space Shuttle mission flown by Space Shuttle ''Discovery'', the Pressurized Module of Kibō was added to the port side of ''Harmony'' and the ELM-PS was moved, leaving the zenith hatch empty. The zenith hatch was originally intended to be the permanent docking connector for the now canceled Centrifuge Accommodations Module (CAM).

When the Space Shuttle flew the Multi-Purpose Logistics Modules (MPLMs) to the station, the MPLM would be temporarily berthed to the nadir mechanism of ''Harmony''. The Japanese H-II Transfer Vehicle and the American Commercial Resupply Service (COTS) vehicles, Dragon and Cygnus, are temporarily berthed to either the nadir or zenith mechanism.

In August 2016, the forward docking port was equipped with the International Docking Adapter (IDA) delivered with the CRS-9 mission. This adapter was used for the first time for the automatic docking of the Crew Dragon spacecraft during its uncrewed test mission on 3 March 2019.

File:STS-132 Atlantis at ISS 1.jpg, Space Shuttle docked to PMA-2
File:MPLM berthed to Node 2.jpg, MPLM berthed to Node 2 nadir
File:HTV-3 berthed to Harmony nadir.jpg, HTV being berthed to Node 2 nadir
File:COTS2 Dragon is berthed.jpg, Dragon being berthed to Node 2 nadir
File:Orb CRS-1 unberthing - crop.jpg, Cygnus being unberthed from Node 2 nadir
File:Canadarm2 moving Harmony node into position.jpg, Canadarm2 moving the ''Harmony'' module into position on the ISS
File:Both commercial Crew vehicles Crew Dragon and Starliner docked to ports on harmony module at the same time.png, Both Commercial Crew vehicles Crew Dragon and Starliner docked to zenith and forward ports on harmony module at the same time
File:Commercial Crew Program vehicles.jpg, Commercial Crew Program vehicles Starliner and Dragon

On 26 March 2017, PMA-3 was robotically removed from the ''Tranquility'' module and attached to the zenith port of the ''Harmony'' module after being prepared during a successful spacewalk on 24 March 2017. A second spacewalk was conducted on 30 March 2017 to finalize the PMA-3 cable connections on ''Harmony''. PMA-3 is linked to the International Docking Adapter-3 adapter, delivered on the SpaceX CRS-18 mission in July 2019. IDA-3 was fully linked to PMA-3 during an EVA on 21 August 2019.

References

External links

Node 2 specifications from the ESA





Thales Alenia Space page for Node 2

{{Orbital launches in 2007

Components of the International Space Station
Spacecraft launched in 2007