_Section 6 of the INA bans U.S. payments to Russia in connection with the International Space Station (ISS) unless the U.S. President determines that Russia is taking steps to prevent such proliferation. The ISS is currently under construction in orbit. According to current plans, the National Aeronautics and Space Administration (NASA) will become dependent on Russia for certain ISS crew-related services beginning in April 2006 for which NASA must pay._

Basically, the Act prevents NASA from paying fees to Russia for use of the Russian sections of the station, which means that NASA astronauts can really only use the station when a Shuttle is docked there. Fun!