Using cellphones on aeroplanes could drown out faint radio signals from space, astronomers are warning. They told a US agency considering lifting in-flight restrictions on cellphones that special devices should be installed on planes to limit damage to research if the regulations change. US law currently prohibits aeroplane passengers from using cellphones because they may interfere with critical aircraft electronics. But the dramatic use of cellphones by passengers on the planes hijacked on 11 September 2001 spurred many people to petition the government to change this policy. "It was not the cellphones that caused those planes to crash," says Paul Feldman, a telecommunications lawyer at the firm Fletcher, Heald and Hildreth in Arlington, Virginia, US. "For better or worse, there's an increasing expectation that people can use their cellphones everywhere, all the time." Now two government agencies - which would probably both have to agree to lift the ban - are reviewing the issue. The Federal Aviation Administration may reverse its policy depending on the results of a study on how cellphones affect flight safety. The study should be finished in January 2006. Meanwhile, the Federal Communications Commission (FCC) has asked for public comments on the possibility of lifting its restrictions, which were originally put in place because of the strain that cellphone use could put on ground-based wireless networks [New Scientist]