The International Docking System Standard (IDSS) is an international standard for spacecraft docking adapters. It was created by the International Space Station Multilateral Coordination Board, on behalf of the International Space Station partner organizations; NASA, Roscosmos, JAXA, ESA, and the Canadian Space Agency.
The IDSS was originally formulated in 2010. [1] The plan is for all cooperating agencies to make their future docking systems IDSS compatible.[ citation needed ]
The IDSS docking mechanism can be androgynous, uses low impact technology, and allows both docking and berthing. [2] It supports both autonomous and piloted docking and features pyrotechnics for contingency undocking. Once mated, the IDSS interface can transfer power, data, commands, air, communication, and in future implementations, will be able to transfer water, fuel, oxidizer and pressurant as well. [3]
The passage for crew and cargo transfer has a diameter of 0.8 meters (31 in). [4]
The IDSS has a 2-phase docking procedure consisting of a soft capture and hard capture system.
During a docking maneuver, one vehicle assumes the "active" role and the other vehicle assumes the "passive" role. A particular IDSS port can be manufactured to be able to act in the active role, the passive role, or either role. If a port (e.g., the ones on the ISS) is passive-only, then the other spacecraft must implement the active role. If a port is active-only (e.g., the ports on Crew Dragon and Cargo Dragon, and Starliner), then the other spacecraft must implement the passive role. This means that spacecraft with active-only ports cannot dock with each other using these ports. [4]
The soft capture system (SCS) of the active docking system is extended while the passive system remains retracted. Each SCS includes 3 equally spaced petals around the docking ring. As the spacecraft approach each other, the petals on the SCS align the two docking rings and the two become mechanically latched. 6 servo-actuated legs then remove any relative motion and may begin to retract. The use of the SCS allows for 6 degrees of freedom, reducing the accuracy requirement of initial docking procedures.
Once soft capture is achieved, the hard capture system (HCS) can begin final structural mating. It consists of 12 pairs of mechanical hooks on both the passive and active port. Guide pins are used to ensure accurate alignment of the docking rings to properly allow the hooks to engage. Once the hooks are fully driven, the docking ports' electrical connectors can begin transferring data and the docking procedure is complete. [5]
The NASA Docking System is NASA's implementation of the IDSS. [6] The International Docking Adapter (IDA) converts older Russian APAS-95 docking systems to the International Docking System Standard. IDA implements the passive IDSS role. NASA set June 2016 as the starting date to construct 4 of the NASA Docking System units for the Commercial Crew Development program. [7] Two International Docking Adapters were added to the International Space Station, and another was destroyed on ascent. [8] As of September 2023 [update] these ports have been used during nineteen SpaceX Dragon 2 missions and one Boeing Starliner mission.
Boeing Starliner uses the NASA Docking System version of IDSS, implementing the active role.
The ESA's International Berthing and Docking Mechanism is their IDSS compatible docking system.
Lunar Gateway will be assembled in lunar orbit from modules that connect to each other using IDSS ports. Visiting spacecraft (Orion, HLS, GLS) will connect to Gateway using IDSS ports.
In March 2020, Space.com reported that a Chinese crew capsule is possibly IDSS compatible. [9]
SpaceX designed and implemented an IDSS port for the Crew and Cargo Dragons. [10] The ports implement the active role.
In the SpaDeX mission, ISRO will test a subscale version of its IDSS-compatible Bhartiya Docking System (BDS). It uses two motors as opposed to the 24 motors used in other IDSS implementations. [11] [12] The full scale IDSS-compatible version is planned to be integrated into Gaganyaan and Bharatiya Antariksha Station. [13]
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.
A space rendezvous is a set of orbital maneuvers during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance. Rendezvous requires a precise match of the orbital velocities and position vectors of the two spacecraft, allowing them to remain at a constant distance through orbital station-keeping. Rendezvous may or may not be followed by docking or berthing, procedures which bring the spacecraft into physical contact and create a link between them.
The terms Androgynous Peripheral Attach System (APAS), Androgynous Peripheral Assembly System (APAS) and Androgynous Peripheral Docking System (APDS) are used interchangeably to describe a Russian family of spacecraft docking mechanisms, and are also sometimes used as generic names for any docking system in that family. A system similar to APAS-89/95 is used by the Chinese Shenzhou spacecraft.
The NASA Docking System is NASA's implementation of the International Docking System Standard (IDSS), an international spacecraft docking standard promulgated by the International Space Station Multilateral Coordination Board. NDS is a spacecraft docking and berthing mechanism used on the International Space Station (ISS) and the Boeing Starliner and planned to be used on the Orion spacecraft. The international Low Impact Docking System (iLIDS) was the precursor to the NDS. NDS Block 1 was designed, built, and tested by The Boeing Company in Huntsville Alabama. Design qualification testing took place through January 2017.
A Pressurized Mating Adapter (PMA) is a component used on the International Space Station (ISS) to convert the Common Berthing Mechanism (CBM) interface used to connect ISS modules to an APAS-95 spacecraft docking port. Three PMAs are attached to the US Orbital Segment of ISS. PMA-1 and PMA-2 were launched along with the Unity module in 1998 aboard STS-88; PMA-3 was launched in 2000 aboard STS-92. PMA-1 permanently connects the Unity and Zarya modules. International Docking Adapters were permanently installed on PMA-2 and PMA-3 in 2017 to convert them from the APAS-95 standard to the newer International Docking System Standard (IDSS).
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The Boeing Starliner is a spacecraft designed to transport crew to and from the International Space Station (ISS) and other low-Earth-orbit destinations. Developed by Boeing under NASA's Commercial Crew Program (CCP), it consists of a reusable crew capsule and an expendable service module.
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Docking and berthing of spacecraft is the joining of two space vehicles. This connection can be temporary, or partially permanent such as for space station modules.
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The International Berthing and Docking Mechanism (IBDM) is the European androgynous low impact docking mechanism that is capable of docking and berthing large and small spacecraft. The development of the IBDM is under ESA contract with QinetiQ Space as prime contractor.
The International Docking Adapter (IDA) is a spacecraft docking system adapter developed to convert APAS-95 to support docking with spacecraft that implement the International Docking System Standard. The IDA uses NASA Docking System (NDS) hardware. An IDA was permanently installed on each of the International Space Station's (ISS) two open Pressurized Mating Adapters (PMAs), both of which are connected to the Harmony module.
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