At the International Space Station, the first track of what will eventually be a 360-foot space railway has been laid. The space shuttle Atlantis delivered the initial 43-foot section of track, called a truss, in April. Eventually, the railway will enable astronauts and cosmonauts to transport equipment and people for the maintenance of the complex. The rail line will be formed by a series of nine trusses delivered by space shuttles over the next two years, according to Kyle Herring, a NASA spokesman. The trusses will support the Mobile Transporter, as the railcar has been named, which weighs nearly a ton and measures three feet high, nine feet long and eight feet wide. The railcar, built by TRW Astro in Carpinteria, Calif., is literally inches along. Its maximum speed is estimated at one inch per second (or five feet per minute). However, it can also transport 23 tons of cargo. Three sets of wheels keep the rail vehicle on its tracks, including one set that ensures the car cannot disengage and float off into space. The railway also includes a Canadian-built robotic arm that will service the exterior of the space station. Canadarm2 will travel the length of the track to deliver segments and necessary equipment for future installation. This mechanical arm can be controlled from the space station or from Mission Control in Houston. A handcar for astronauts and cosmonauts, known as the Crew and Equipment Translation Aid, will allow crew members to move themselves and their equipment up and down the track, facilitating station work. Two carts are expected to be delivered by the end of the year. Later this year, more installments of the truss are scheduled, including two on the port and starboard sides of the existing S0 (S-zero) truss. “Basically what we did on the Atlantis mission was set the stage for the expansion of those truss segments,” Herring said.