ISS has following major components:
Control module- the zarya control module was the first component launched. Zarya was technically known as the functional cargo block. The Zarya Module is 12.6 meters long and 4.1 meters at its widest point. It has an operational lifetime of at least 15 years. Its solar arrays and six nickel-cadmium batteries can provide an average of 3 kilowatts of electrical power. This project was funded by U.S and built by Russia . It controls the orientation and communication. It stores fuel and provides docking point to the service module
• Service module- Zvezda service module is the first fully Russian contribution to the international space station. The module provides the station with living quarters, life support system, electrical power distribution, data processing system, flight control system and propulsion system. It also provides a communications system that includes remote command capabilities for ground flight controllers
• Pressurized mating adapter- they connect one module to another and serve as pressurized hallways between the components.
• The unity node- The Unity Node is a connecting passageway to living and work areas of the International Space Station. It is the first major U.S.-built component of the station. Pressurized mating adapter attached the unity node to the control module.
• Airlock- it is attached to the unity and is the connecting passageway for the station. It makes it possible for the astronauts to conduct space walk directly.
• Thermal control panels- much of the cargo and equipments have to be kept at a specific temperature. This system incorporates insulation, surface coatings, heaters and pumps to transfer heat. This maintains the right temperature in each area of the ISS.
• The docking module- It provides additional docking ports and rooms to store the materials temporarily. It is also known as stowage module.
• The universal docking module- it provides docking locations for the Russian research module. It has the capability of providing additional life support systems.
• Node 3- connects the habitation module to the rest of the ISS. It also provides access to the docked crew return vehicle.
• Transfer vehicle- soyuz capsule is a launch vehicle that is used to transport space station elements, supplies and astronauts from earth to the orbiting ISS.
The ISS orbits around the earth at an altitude of 217 to 285 miles. At this height, the earth's atmosphere is thick enough to drag ISS down. This causes it to lose its altitude. Thus it has to be periodically boosted to maintain a proper altitude. The command and service modules are used to boost in early stages and progress supply ships does the reboosting later on.
The ground communication is carried out by two systems
s- band for voice, commands, telemetry and data files
ku band – video and transfer of two way data files
Ultra high frequencies are used to communicate with the space walkers. External
Connectors are used to talk with a docked space shuttle.
To know the precise location of ISS in space, how fast it is moving; it uses the global positioning system. This information helps it to move from one point to another in space.