Spacecraft docking and berthing mechanism
Encyclopedia
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.
Berthing refers to mating operations where an inactive module/vehicle is placed into the mating interface using a robotic arm.
Androgynous docking, and later androgynous berthing, on the other hand has an identical interface design on both spacecraft, allowing system-level redundancy
(role reversing) as well as rescue and collaboration between any two spacecraft vehicles. In an androgynous interface, there is a single design which can connect to a duplicate of itself. This results in more flexible mission design and reduces unique mission analysis and training.
This is changing. A substantial number of economically driven commercial dockings of unmanned spacecraft are planned starting as soon as 2015. In early 2011, two commercial spacecraft providers have announced plans to provide new autonomous
/teleoperated
unmanned resupply spacecraft
for servicing other unmanned spacecraft. Notably, both of these servicing spacecraft will be intending to dock with satellites that were not designed for docking, nor in-space servicing.
The early business model for these services is primarily in near-geosynchronous orbit, although large delta-v
orbital maneuver
ing services are also envisioned.
Building off of the 2007 Orbital Express
mission — a U.S. government
-sponsored mission to test in-space satellite servicing with two vehicles designed from the ground up for on-orbit refueling and subsystem replacement — two companies have announced new commercial satellite servicing missions that will require docking of two unmanned vehicles.
The SIS and MEV vehicles will each use a different docking technique.
SIS will utilize a ring attachment around the kick motor
while the Mission Extension Vehicle will use a somewhat more standard insert-a-probe-into-the-nozzle-of-the-kick-motor approach.
A typical approach for solving this problem involves two phases. First, attitude and orbital
changes are made to the "chaser" spacecraft until it has zero relative motion with the "target" spacecraft. Second, docking maneuvers commence that are similar to traditional cooperative spacecraft docking. A standardized docking interface on each spacecraft is assumed.
NASA has identified automated and autonomous rendezvous and docking — the ability of two spacecraft to rendezvous and dock "operating independently from human controllers and without other back-up, [and which requires technology] advances in sensors, software, and realtime
on-orbit positioning and flight control, among other challenges" — as a critical technology to the "ultimate success of capabilities such as in-orbit propellant storage and refueling
," and also for complex operations in assembling mission components for interplanetary destinations.
The Automated/Autonomous Rendezvous & Docking Vehicle (ARDV) is a proposed NASA Flagship Technology Demonstration (FTD) mission, for flight as early as 2014/2015. An important NASA objective on the proposed mission is to advance the technology and demonstrate automated rendezvous and docking. One mission element defined in the 2010 analysis was the development of a laser proximity operations sensor that could be used for non-cooperative vehicles at distances between 1 metres (3.3 ft) and 3 kilometres (1.9 mi). Non-cooperative docking mechanisms were identified as critical mission elements to the success of such autonomous missions.
Grappling and connecting to non-cooperative space objects was identified as a top technical challenge in the 2010 NASA Robotics, tele-robotics and autonomous systems roadmap.
Berthing refers to mating operations where an inactive module/vehicle is placed into the mating interface using a robotic arm.
Types
| Image | Name | Method | Internal Crew Transfer | Use | Type |
|---|---|---|---|---|---|
| Gemini Docking Mechanism | Docking | No | Gemini Spacecraft, Agena target vehicle Agena Target Vehicle The Agena Target Vehicle was an unmanned spacecraft used by NASA during its Gemini program to develop and practice orbital space rendezvous and docking techniques and to perform large orbital changes, in preparation for the Apollo program lunar missions.-Operations:Each ATV consisted of an Agena-D... |
Non-Androgynous | |
| Original Russian probe and drogue docking system | Docking | No | Soyuz 7K-OK Soyuz 7K-OK The manned Soyuz spacecraft can be classified into design generations. Soyuz 1 through Soyuz 11 were first-generation vehicles, carrying a crew of up to three without spacesuits and distinguished from those following by their bent solar panels and their use of the Igla automatic docking navigation... |
Non-Androgynous | |
| Apollo Docking Mechanism | Docking | Yes | Apollo Spacecraft Apollo Command/Service Module The Command/Service Module was one of two spacecraft, along with the Lunar Module, used for the United States Apollo program which landed astronauts on the Moon. It was built for NASA by North American Aviation... , Apollo Lunar Module Apollo Lunar Module The Apollo Lunar Module was the lander portion of the Apollo spacecraft built for the US Apollo program by Grumman to carry a crew of two from lunar orbit to the surface and back... , Skylab Skylab Skylab was a space station launched and operated by NASA, the space agency of the United States. Skylab orbited the Earth from 1973 to 1979, and included a workshop, a solar observatory, and other systems. It was launched unmanned by a modified Saturn V rocket, with a mass of... , Docking Module (ASTP) |
Non-Androgynous | |
| Modern Russian probe and drogue docking system | Docking | Yes | Post Soyuz 7K-OK, Progress, ATV Automated Transfer Vehicle The Automated Transfer Vehicle or ATV is an expendable, unmanned resupply spacecraft developed by the European Space Agency . ATVs are designed to supply the International Space Station with propellant, water, air, payload and experiments... , Salyut stations, 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... , ISS ISS The ISS is the International Space Station.ISS may also refer to:* I See Stars, an American electronic rock band* ISS A/S, a Danish service company* Idea Star Singer, a Malayalam music reality show by Asianet TV... (Russian modules) |
Non-Androgynous | |
| APAS-75 | Docking | Yes | Docking Module (ASTP), Soyuz 7K-TM Soyuz 7K-TM Apollo-Soyuz Test Project 1975 version of the Soyuz spacecraft served as a technological bridge to the third generation Soyuz-T spacecraft .... |
Androgynous | |
| APAS-89 | Docking | Yes | Mir (Kristall Kristall The Kristall module was the fourth module and the third major addition to the Mir space station. As with previous modules, its configuration was based on the 77K module, and was originally named "Kvant 3". It was launched on May 31, 1990 on a Proton rocket... , Mir Docking Module Mir Docking Module The Stykovochnyy Otsek , GRAU index 316GK, otherwise known as the Mir docking module or SO, was the sixth module of the Russian space station Mir, launched in November 1995 aboard the... ), Soyuz TM-16 Soyuz TM-16 -Crew:-Mission highlights:16th expedition to Mir.First Soyuz without a probe and drogue docking system since 1976. It carriedan APAS-89 androgynous docking unit different from the APAS-75 unit used for ASTP in 1975, yet similar in general principles. Soyuz-TM 16 used it to dock with an androgynous... , ISS (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... ) |
Androgynous | |
| APAS-95 | Docking | Yes | Space Shuttle Space 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... , Pressurized Mating Adapter Pressurized Mating Adapter The International Space Station uses three Pressurized Mating Adapters to interconnect spacecraft and modules with different docking mechanisms. The first two PMAs were launched with the Unity module in 1998 aboard STS-88... |
Androgynous (Shuttle and PMA-1), Non-Androgynous (PMA-2 and PMA-3) | |
| Hybrid Docking System | Docking | Yes | Connects Zvezda to 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... , Pirs & Poisk ISS ISS The ISS is the International Space Station.ISS may also refer to:* I See Stars, an American electronic rock band* ISS A/S, a Danish service company* Idea Star Singer, a Malayalam music reality show by Asianet TV... modules |
Non-Androgynous | |
| 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.... |
Berthing | Yes | ISS ISS The ISS is the International Space Station.ISS may also refer to:* I See Stars, an American electronic rock band* ISS A/S, a Danish service company* Idea Star Singer, a Malayalam music reality show by Asianet TV... , MPLMs 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... , HTV H-II Transfer Vehicle The H-II Transfer Vehicle , called , is an unmanned resupply spacecraft used to resupply the Kibō Japanese Experiment Module and the International Space Station . The Japan Aerospace Exploration Agency has been working on the design since the early 1990s. The first mission, HTV-1, was originally... , Dragon Cargo Dragon (spacecraft) The Dragon is a reusable spacecraft developed by SpaceX, a private space transportation company based in Hawthorne, California. During its unmanned maiden flight in December 2010, it became the first commercially-built and -operated spacecraft to ever be successfully recovered from orbit.The Dragon... , Cygnus Cygnus spacecraft The Cygnus spacecraft is an unmanned resupply spacecraft being developed by Orbital Sciences Corporation and Thales Alenia Space as part of NASA's COTS project. It is designed to transport supplies to the International Space Station after the retirement of the Space Shuttle... |
Non-Androgynous | |
| NASA Docking System | Docking or Berthing | Yes | NDS APAS Docking Adapter, future US vehicles | Androgynous | |
Androgyny
Early systems for conjoining spacecraft were all non-androgynous docking system designs. Non-androgynous designs are a form of "gender mating" where each spacecraft to be joined has a unique design and a specific role to play in the docking process. The roles cannot be reversed. Furthermore, two spacecraft of the same gender cannot be joined at all.Androgynous docking, and later androgynous berthing, on the other hand has an identical interface design on both spacecraft, allowing system-level redundancy
Redundancy (engineering)
In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the case of a backup or fail-safe....
(role reversing) as well as rescue and collaboration between any two spacecraft vehicles. In an androgynous interface, there is a single design which can connect to a duplicate of itself. This results in more flexible mission design and reduces unique mission analysis and training.
Adapters
A docking or berthing adapter is a mechanical or electromechanical device that facilitates the connection of one type of docking or berthing interface to a different interface. While such interfaces may theoretically be docking/docking, docking/berthing, or berthing/berthing, only the first two types have been deployed in space to date. Previously launched and planned to be launched adapters are listed below:- Docking Module: Converts U.S. Probe and Drogue to APAS-75Androgynous Peripheral Attach SystemThe 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...
. Built for the 1975 Apollo–Soyuz Test Project mission.
- Pressurized Mating Adapter (PMA)Pressurized Mating AdapterThe International Space Station uses three Pressurized Mating Adapters to interconnect spacecraft and modules with different docking mechanisms. The first two PMAs were launched with the Unity module in 1998 aboard STS-88...
: Converts an active Common Berthing MechanismCommon Berthing MechanismThe common berthing mechanism is a berthing mechanism used to connect all non-Russian pressurized modules of the International Space Station....
to the Androgynous Peripheral Attach SystemAndrogynous Peripheral Attach SystemThe 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...
. Three PMAs are attached to the ISSISSThe ISS is the International Space Station.ISS may also refer to:* I See Stars, an American electronic rock band* ISS A/S, a Danish service company* Idea Star Singer, a Malayalam music reality show by Asianet TV...
, PMA-1 and PMA-2 were launched in 1998 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...
, PMA-3 in late 2000 on STS-92STS-92STS-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...
.
- NDS APAS Docking Adapter (NADA): Will be attached to ISS's two open PMAs, it will convert APAS-95 to the NASA Docking System (NDS). Two of them will be attached to Node 2 (Harmony module) of the International Space Station, the first in late 2014 and the second in either 2015 or 2016. One will be attached to Node-2's forward port and the other to its zenith port. The adapter will be compatible with the International Docking System Standard (IDSS), which is an attempt by the ISS Multilateral Coordination Board to create a docking standard.
Docking of two unmanned spacecraft
During the first fifty years of spaceflight, most docking, and all berthing, of spacecraft have been of vehicles where at least one of the two were so-called "manned spacecraft", with docking to a pressurized habitable volume a necessary part of the technical objective.This is changing. A substantial number of economically driven commercial dockings of unmanned spacecraft are planned starting as soon as 2015. In early 2011, two commercial spacecraft providers have announced plans to provide new autonomous
Autonomous robot
Autonomous robots are robots that can perform desired tasks in unstructured environments without continuous human guidance. Many kinds of robots have some degree of autonomy. Different robots can be autonomous in different ways...
/teleoperated
Teleoperation
Teleoperation indicates operation of a machine at a distance. It is similar in meaning to the phrase "remote control" but is usually encountered in research, academic and technical environments...
unmanned resupply spacecraft
Unmanned resupply spacecraft
Unmanned resupply spacecraft are a special kind of robotic spacecraft that operate autonomously without a human crew, designed to support space station operation...
for servicing other unmanned spacecraft. Notably, both of these servicing spacecraft will be intending to dock with satellites that were not designed for docking, nor in-space servicing.
The early business model for these services is primarily in near-geosynchronous orbit, although large delta-v
Delta-v
In astrodynamics a Δv or delta-v is a scalar which takes units of speed. It is a measure of the amount of "effort" that is needed to change from one trajectory to another by making an orbital maneuver....
orbital maneuver
Orbital maneuver
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft.For spacecraft far from Earth—for example those in orbits around the Sun—an orbital maneuver is called a deep-space maneuver .-delta-v:...
ing services are also envisioned.
Building off of the 2007 Orbital Express
Orbital Express
thumb|Orbital Express: ASTRO and NEXTSatOrbital Express was a space mission managed by the United States Defense Advanced Research Projects Agency and a team led by engineers at NASA's Marshall Space Flight Center...
mission — a U.S. government
Federal government of the United States
The federal government of the United States is the national government of the constitutional republic of fifty states that is the United States of America. The federal government comprises three distinct branches of government: a legislative, an executive and a judiciary. These branches and...
-sponsored mission to test in-space satellite servicing with two vehicles designed from the ground up for on-orbit refueling and subsystem replacement — two companies have announced new commercial satellite servicing missions that will require docking of two unmanned vehicles.
- Space Infrastructure ServicingSpace Infrastructure ServicingSpace Infrastructure Servicing is a spacecraft being developed by Canadian aerospace firm MacDonald, Dettwiler and Associates to operate as a small-scale in-space refueling depot for communication satellites in geosynchronous orbit...
(SIS) is a spacecraftSpacecraftA spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
being developed by CanadianCanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
aerospace firm MacDonald, Dettwiler and Associates (MDA)—maker of Canadarm—to operate as a small-scale in-space refueling depotPropellant depotAn orbital propellant depot is a cache of propellant that is placed on an orbit about the Earth or another body to allow spacecraft to be fuelled in space. Launching a spacecraft separately from some of its propellant enables missions with more massive payloads...
for communication satellites in geosynchronous orbitGeosynchronous orbitA geosynchronous orbit is an orbit around the Earth with an orbital period that matches the Earth's sidereal rotation period...
. IntelsatIntelsatIntelsat, Ltd. is a communications satellite services provider.Originally formed as International Telecommunications Satellite Organization , it was—from 1964 to 2001—an intergovernmental consortium owning and managing a constellation of communications satellites providing international broadcast...
is a requirementsProduct requirements documentA product requirements document is a document written by a company that defines a product they are making, or the requirements for one or more new features for an existing product...
and fundingProject financeProject finance is the long term financing of infrastructure and industrial projects based upon the projected cash flows of the project rather than the balance sheets of the project sponsors...
partner for the initial demonstration satellite, aimed to be launched in approximately 2015.
- Mission Extension VehicleMission Extension VehicleThe Mission Extension Vehicle is a spacecraft concept proposed by ViviSat, a 50/50 joint venture of aerospace firms U.S. Space and ATK, to operate as a small-scale in-space satellite-refueling spacecraft.-Technical capabilities and competition:...
(MEV) is a spacecraftSpacecraftA spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
being developed by the U.S. firmUnited StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
ViviSat, a 50/50 joint venture of aerospace firms U.S. Space and ATKAlliant TechsystemsAlliant Techsystems Inc., most commonly known by its ticker symbol, ', is one of the largest aerospace and defense companies in the United States with more than 18,000 employees in 22 states, Puerto Rico and internationally, and 2010 revenues in excess of an estimated...
, to operate as a small-scale in-space satellite-refueling spacecraftPropellant depotAn orbital propellant depot is a cache of propellant that is placed on an orbit about the Earth or another body to allow spacecraft to be fuelled in space. Launching a spacecraft separately from some of its propellant enables missions with more massive payloads...
. MEV will dock but will not transfer fuel. It will rather use "its own thrustersReaction control systemA reaction control system is a subsystem of a spacecraft whose purpose is attitude control and steering by the use of thrusters. An RCS system is capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow...
to supply attitude control for the target."
The SIS and MEV vehicles will each use a different docking technique.
SIS will utilize a ring attachment around the kick motor
Apogee kick motor
An apogee kick motor refers to a rocket motor that is regularly employed on artificial satellites destined for a geostationary orbit. As the vast majority of geostationary satellite launches are carried out from spaceports at a significant distance away from Earth's equator, the carrier rocket...
while the Mission Extension Vehicle will use a somewhat more standard insert-a-probe-into-the-nozzle-of-the-kick-motor approach.
Non-cooperative docking
All spacecraft dockings to date have been accomplished with vehicles where both spacecraft involved were under either piloted, autonomous or telerobotic attitude control. However, it might be desirable to dock with a spacecraft that does not have an operable attitude control system, for purposes of repair or disposal. Theoretical techniques for docking with non-cooperative spacecraft have been proposed.A typical approach for solving this problem involves two phases. First, attitude and orbital
Orbit (dynamics)
In mathematics, in the study of dynamical systems, an orbit is a collection of points related by the evolution function of the dynamical system. The orbit is a subset of the phase space and the set of all orbits is a partition of the phase space, that is different orbits do not intersect in the...
changes are made to the "chaser" spacecraft until it has zero relative motion with the "target" spacecraft. Second, docking maneuvers commence that are similar to traditional cooperative spacecraft docking. A standardized docking interface on each spacecraft is assumed.
NASA has identified automated and autonomous rendezvous and docking — the ability of two spacecraft to rendezvous and dock "operating independently from human controllers and without other back-up, [and which requires technology] advances in sensors, software, and realtime
Real-time Control System
Real-time Control System is a reference model architecture, suitable for many software-intensive, real-time control problem domains. RCS is a reference model architecture that defines the types of functions that are required in a real-time intelligent control system, and how these functions are...
on-orbit positioning and flight control, among other challenges" — as a critical technology to the "ultimate success of capabilities such as in-orbit propellant storage and refueling
Propellant depot
An orbital propellant depot is a cache of propellant that is placed on an orbit about the Earth or another body to allow spacecraft to be fuelled in space. Launching a spacecraft separately from some of its propellant enables missions with more massive payloads...
," and also for complex operations in assembling mission components for interplanetary destinations.
The Automated/Autonomous Rendezvous & Docking Vehicle (ARDV) is a proposed NASA Flagship Technology Demonstration (FTD) mission, for flight as early as 2014/2015. An important NASA objective on the proposed mission is to advance the technology and demonstrate automated rendezvous and docking. One mission element defined in the 2010 analysis was the development of a laser proximity operations sensor that could be used for non-cooperative vehicles at distances between 1 metres (3.3 ft) and 3 kilometres (1.9 mi). Non-cooperative docking mechanisms were identified as critical mission elements to the success of such autonomous missions.
Grappling and connecting to non-cooperative space objects was identified as a top technical challenge in the 2010 NASA Robotics, tele-robotics and autonomous systems roadmap.