Columbus module. Cut-away artwork showing the interior of the Columbus Orbital Facility (COF) or Attached Pressurised Module whilst attached to the International Space Station (ISS). Astronauts can be seen working within the COF, which is part of the European Space Agency's contribution to the ISS. The ISS is being funded mainly by the USA and Russia. The ISS will be used to study the effects of minute levels of gravity (microgravity) on materials and biological tissue. The COF is planned to be installed in the final phase of the ISS's construction in September 2001. The ISS should commence operation with a crew of six in June 2002.