Pressurized Mating Adapter
Encyclopedia
The International Space Station
(ISS) uses three Pressurized Mating Adapters (PMAs) to interconnect spacecraft and modules with different docking mechanisms
. The first two PMAs were launched with the Unity module in 1998 aboard STS-88
. The third was launched in 2000 aboard STS-92
.
All the PMAs on the ISS are identical but used slightly differently, and all three perform the same basic function of connecting a common berthing mechanism
(CBM) port of an ISS module to the Androgynous Peripheral Attach System
(APAS) docking port of another module or visiting spacecraft.
For this the PMAs carry a passive CBM port and a passive APAS port. They are pressurized and heated from the inside, and through docking rings as well as external connections allow for power and data communications transfer.
the crew used the shuttle's robotic arm to attach the Zarya
control module to PMA-1, which was already connected to the aft berthing port of Unity. PMA-1 now permanently connects these first two station components.
orbiters dock at the station. It is the only PMA that has been outfitted with Station-to-Shuttle Power Transfer System (SSPTS) hardware, which allowed shuttles to stay docked longer to the space station.
Due to space station assembly PMA-2 has been moved several times. It was originally connected to the forward hatch of Unity, but when STS-98
delivered the Destiny
in February 2001, Destiny was berthed to that hatch while PMA-2 was moved to the forward hatch of the Z1 truss. It was finally moved to the forward hatch of "Destiny".
(The removal of PMA-2 from Unity was the first time the Common Berthing Mechanism
(CBM) was used to disconnect two ISS components.)
After STS-120
had delivered Harmony at the station in October 2007, Canadarm2 relocated PMA-2 to its final location at the forward hatch of Harmony on November 12, 2007. Two days later, the combined package of Harmony and PMA-2 was moved to its final location, the forward hatch of Destiny. PMA-2 will stay berthed at the forward port of Harmony for the remaining duration of the ISS.
When a shuttle docks with the station, its "final approach [is] at a relative velocity of one-tenth of a foot per second. [As it] makes contact with Pressurized Mating Adapter 2 [latches] automatically attach the two spacecraft together. Once relative motion between the spacecraft stops, [a shuttle astronaut] retracts the docking ring on [the shuttle's] mechanism, closing latches to firmly secure the shuttle to the station."
brought PMA-3, mounted on a Spacelab
pallet, to the station.
It was initially attached to the nadir (bottom, or Earth-facing) hatch of Unity. One and a half months later, when STS-97
delivered the P6 solar array truss structure, Endeavour docked at PMA-3.
Also, when STS-98
moved PMA-2 from Unity to Destiny via Z1, Atlantis was docked at PMA-3. PMA-3 has not been used for Shuttle docking since STS-98.
PMA-3 was moved in March 2001 to Unitys port hatch by the crew of STS-102
to make room for the docking of a Multi-Purpose Logistics Module
(MPLM).
On August 30, 2007, PMA-3 was moved to the nadir port of Unity to make room for the temporary docking of the new Harmony module that was delivered by STS-120
. Harmony was transferred to the forward port of Destiny, while PMA-3 was moved back to the port berthing mechanism of Unity around early 2009. But, on January 25, 2010, PMA-3 was moved from Unity to the zenith (space facing) port of Harmony from the port berthing mechanism of Unity to make room for the new Tranquility (Node 3) module which was added to the station during STS-130
. After activation of Tranquility, PMA-3 was moved again on February 16, 2010 to the outer port on Tranquility where the Cupola had been docked for launch.
. Boeing had earlier constructed a similar adapter which allowed the U.S. Space Shuttle to dock with Russia's Mir
space station.
International Space Station
The International Space Station is a habitable, artificial satellite in low Earth orbit. The ISS follows the Salyut, Almaz, Cosmos, Skylab, and Mir space stations, as the 11th space station launched, not including the Genesis I and II prototypes...
(ISS) uses three Pressurized Mating Adapters (PMAs) to interconnect spacecraft and modules with different docking mechanisms
Spacecraft docking and berthing mechanism
Spacecraft docking and berthing mechanisms are used to join two spacecraft. Docking specifically refers to the joining or coming together of two separate free flying space vehicles....
. The first two PMAs were launched with the Unity module in 1998 aboard STS-88
STS-88
-Mission parameters:*Weight*Liftoff: *Landing: *Perigee: *Apogee: *Orbital Period: 92.4min-Launch attempts:-Mission highlights:Node 1, named Unity, was the first space station hardware delivered by the space shuttle. It has two Pressurized Mating Adapters , one attached to either end...
. The third was launched in 2000 aboard STS-92
STS-92
STS-92 was a Space Shuttle mission to the International Space Station flown by Space Shuttle Discovery. STS-92 marked the 100th mission of the Space Shuttle...
.
Uses
Common Berthing Mechanism
The common berthing mechanism is a berthing mechanism used to connect all non-Russian pressurized modules of the International Space Station....
(CBM) port of an ISS module to the Androgynous Peripheral Attach System
Androgynous Peripheral Attach System
The Androgynous Peripheral Attach System, or Androgynous Peripheral Assembly System, is a spacecraft docking mechanism used on the International Space Station. It is used to dock the Space Shuttle orbiter and to connect the Functional Cargo Block to Pressurized Mating Adapter-1...
(APAS) docking port of another module or visiting spacecraft.
For this the PMAs carry a passive CBM port and a passive APAS port. They are pressurized and heated from the inside, and through docking rings as well as external connections allow for power and data communications transfer.
PMA-1
This was one of the first components of the International Space Station and joins the Russian side of the station with the US side. On STS-88STS-88
-Mission parameters:*Weight*Liftoff: *Landing: *Perigee: *Apogee: *Orbital Period: 92.4min-Launch attempts:-Mission highlights:Node 1, named Unity, was the first space station hardware delivered by the space shuttle. It has two Pressurized Mating Adapters , one attached to either end...
the crew used the shuttle's robotic arm to attach the Zarya
Zarya
Zarya , also known as the Functional Cargo Block or FGB , was the first module of the International Space Station to be launched. The FGB provided electrical power, storage, propulsion, and guidance to the ISS during the initial stage of assembly...
control module to PMA-1, which was already connected to the aft berthing port of Unity. PMA-1 now permanently connects these first two station components.
PMA-2
PMA-2 is currently mounted on the forward port of the Harmony connecting node and used when Space ShuttleSpace Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
orbiters dock at the station. It is the only PMA that has been outfitted with Station-to-Shuttle Power Transfer System (SSPTS) hardware, which allowed shuttles to stay docked longer to the space station.
Due to space station assembly PMA-2 has been moved several times. It was originally connected to the forward hatch of Unity, but when STS-98
STS-98
STS-98 was a 2001 Space Shuttle mission to the International Space Station flown by Space Shuttle Atlantis. STS-98 delivered to the station the Destiny Laboratory Module...
delivered the Destiny
Destiny Laboratory Module
The Destiny module is the primary operating facility for U.S. research payloads aboard the International Space Station . It was berthed to the Unity module and activated over a period of five days in February, 2001...
in February 2001, Destiny was berthed to that hatch while PMA-2 was moved to the forward hatch of the Z1 truss. It was finally moved to the forward hatch of "Destiny".
(The removal of PMA-2 from Unity was the first time the Common Berthing Mechanism
Common Berthing Mechanism
The common berthing mechanism is a berthing mechanism used to connect all non-Russian pressurized modules of the International Space Station....
(CBM) was used to disconnect two ISS components.)
After STS-120
STS-120
-Crew notes:As commander of STS-120, Pamela Melroy became the second woman to command a space shuttle mission. Additionally, the Expedition 16 crew that received STS-120 was commanded by Peggy Whitson, the first female ISS commander...
had delivered Harmony at the station in October 2007, Canadarm2 relocated PMA-2 to its final location at the forward hatch of Harmony on November 12, 2007. Two days later, the combined package of Harmony and PMA-2 was moved to its final location, the forward hatch of Destiny. PMA-2 will stay berthed at the forward port of Harmony for the remaining duration of the ISS.
When a shuttle docks with the station, its "final approach [is] at a relative velocity of one-tenth of a foot per second. [As it] makes contact with Pressurized Mating Adapter 2 [latches] automatically attach the two spacecraft together. Once relative motion between the spacecraft stops, [a shuttle astronaut] retracts the docking ring on [the shuttle's] mechanism, closing latches to firmly secure the shuttle to the station."
PMA-3
In October 2000 STS-92STS-92
STS-92 was a Space Shuttle mission to the International Space Station flown by Space Shuttle Discovery. STS-92 marked the 100th mission of the Space Shuttle...
brought PMA-3, mounted on a Spacelab
Spacelab
Spacelab was a reusable laboratory used on certain spaceflights flown by the Space Shuttle. The laboratory consisted of multiple components, including a pressurized module, an unpressurized carrier and other related hardware housed in the Shuttle's cargo bay...
pallet, to the station.
It was initially attached to the nadir (bottom, or Earth-facing) hatch of Unity. One and a half months later, when STS-97
STS-97
STS-97 was a Space Shuttle mission to the International Space Station flown by Space Shuttle Endeavour. The crew installed the first set of solar arrays to the ISS, prepared a docking port for arrival of the Destiny Laboratory Module, and delivered supplies for the station's crew.-Crew:-Mission...
delivered the P6 solar array truss structure, Endeavour docked at PMA-3.
Also, when STS-98
STS-98
STS-98 was a 2001 Space Shuttle mission to the International Space Station flown by Space Shuttle Atlantis. STS-98 delivered to the station the Destiny Laboratory Module...
moved PMA-2 from Unity to Destiny via Z1, Atlantis was docked at PMA-3. PMA-3 has not been used for Shuttle docking since STS-98.
PMA-3 was moved in March 2001 to Unitys port hatch by the crew of STS-102
STS-102
STS-102 was a Space Shuttle mission to the International Space Station flown by Space Shuttle Discovery and launched from Kennedy Space Center, Florida...
to make room for the docking of a Multi-Purpose Logistics Module
Multi-Purpose Logistics Module
A Multi-Purpose Logistics Module is a large pressurized container used on Space Shuttle missions to transfer cargo to and from the International Space Station . An MPLM was carried in the cargo bay of a Shuttle and berthed to the Unity or Harmony modules on the ISS. From there, supplies were...
(MPLM).
On August 30, 2007, PMA-3 was moved to the nadir port of Unity to make room for the temporary docking of the new Harmony module that was delivered by STS-120
STS-120
-Crew notes:As commander of STS-120, Pamela Melroy became the second woman to command a space shuttle mission. Additionally, the Expedition 16 crew that received STS-120 was commanded by Peggy Whitson, the first female ISS commander...
. Harmony was transferred to the forward port of Destiny, while PMA-3 was moved back to the port berthing mechanism of Unity around early 2009. But, on January 25, 2010, PMA-3 was moved from Unity to the zenith (space facing) port of Harmony from the port berthing mechanism of Unity to make room for the new Tranquility (Node 3) module which was added to the station during STS-130
STS-130
STS-130 was a NASA Space Shuttle mission to the International Space Station . 's primary payloads were the Tranquility module and the Cupola, a robotic control station with six windows around its sides and another in the center, providing a 360-degree view around the station...
. After activation of Tranquility, PMA-3 was moved again on February 16, 2010 to the outer port on Tranquility where the Cupola had been docked for launch.
Construction
The three Pressurized Mating Adapters were constructed by BoeingBoeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
. Boeing had earlier constructed a similar adapter which allowed the U.S. Space Shuttle to dock with Russia's Mir
Mir
Mir was a space station operated in low Earth orbit from 1986 to 2001, at first by the Soviet Union and then by Russia. Assembled in orbit from 1986 to 1996, Mir was the first modular space station and had a greater mass than that of any previous spacecraft, holding the record for the...
space station.
See also
- Spacecraft docking and berthing adapters
- ISS assembly sequence