Rails start to go boldly
What NASA describes as the 'first space railroad' has been installed on the International Space Station. An initial 13m section of track was delivered by the shuttle Atlantis in April, and a further 100m is due to be added during the next two years.
A transport vehicle runs along the ISS's S-Zero truss at up to 0·1 km/h, as the station orbits at 27000 km/h. Spring-loaded rollers on both sides of the track ensure the 885 kg transporter does not float loose. Built by TRW Astro, the aluminium vehicle is designed to move 23 tonnes of cargo. It also serves as a mobile base from which a robotic arm will assemble and maintain future truss segments and solar arrays.
Randy Straub, Subcontract Technical Manager with prime contractor Boeing, emphasises that 'it's built for precise positioning and smooth velocity control; it's not built for speed.'