The United States' three-ship space shuttle fleet faces "significant challenges" in its future orbiter work, the U.S. government has warned.
The Government Accountability Office told Congress that completing construction and continuing operation of the $31 billion International Space Station raised the possibility of severe cutbacks, the Houston Chronicle reported from Washington.
Cristina Chaplain of Congress' watchdog agency told a House of Representatives aeronautics subcommittee that NASA must overcome immense odds to complete assembly of the space station on time. Eight shuttle missions are scheduled before the fleet's retirement in 2010.
Copyright 2008 by United Press International
Explore further: The heart of an astronaut, five years on