The International Space Station draws on the resources of 16 nations. The US and Russia are the two main players. The other partners are Japan, Canada and the European Space Agency (Esa), which is made up of eleven countries. Brazil will provide a series of smaller hardware items.

The main elements of the ISS are:

Functional Cargo Block
The first part of the ISS, known by its Russian acronym FGB but also called Zarya which means sunrise, was launched in November 1998. Zarya contains propulsion, command and control systems.

Unity
The first US-built module, called 'Unity' was launched on the Space Shuttle two weeks after Zarya and was docked in space with the FGB. It is station's main connecting module with six ports.

Russian service module
The 13-metre- (42-foot-) service module, or Zvezda, was launched well behind schedule. It contains the living quarters, power control and life-support systems for the first ISS crew. It has three pressurised compartments and 14 windows.

Columbus Orbital Facility
Built by the European Space Agency (Esa), the module will serve as a pressurised laboratory, and will be launched on an Ariane 5 rocket. Esa will also provide transport vehicles to supply the station, called Automated Transfer Vehicles. The first ATV flight to the ISS was scheduled for early in 2003.

Robotic arm
Canada is providing a 17-metre- (55-foot-) long robotic arm called the Mobile Servicing System. Based on the space shuttle's robot arm, which Canada also builds, it will be used for assembly and maintenance tasks and will handle masses almost up to 100 tonnes (220,000 pounds). It will be delivered to the ISS on three assembly flights.

Japanese Experiment Module
The National Space Development Agency of Japan is building the JEM which will provide a pressurised laboratory and an external platform for up to 10 unpressurised experiments.

Brazil
Six items mainly for carrying cargo will be provided by the Brazilian Space Agency.

Mini Pressurised Logistics Modules
In addition to its commitments within the Esa, Italy will develop two mini modules for experiments.