CAPE CANAVERAL, Fla. (Reuters) - NASA on Thursday unveiled a plan to finish the International Space Station that could see construction resume in September after a four-year hiatus and a new laboratory launched next year.
The future of the half-built orbiting research outpost depends on NASA proving that problems have been fixed with its space shuttle fuel tank that caused the 2003 Columbia disaster and reappeared on the only shuttle mission since the accident.
NASA hopes to fly its next shuttle mission as early as May. It would be the first since the flight of Discovery last July.
Construction of the space station has been Delayed by the Columbia accident, in which seven astronauts were killed. NASA's shuttle is the only spaceship with the cargo hold to carry the station's modules and is scheduled for retirement in 2010.
The new schedule of construction flights, agreed at a meeting of the heads of the 16-nation International Space Station partnership, eliminates nearly all flights devoted to science in favor of getting the station's remaining trusses, power systems and modules into orbit.
"The decision was to put together an assembly sequence that allows us high confidence that we will finish the space station by the time the shuttle is retired," NASA administrator Michael Griffin said at a news briefing after the meeting.
To accomplish the goal of launching the remaining space station hardware, all of which was designed to fly exclusively on the shuttle, NASA is paring flights carrying experiments and science equipment "to the bone," Griffin said.
The new schedule calls for 16 more shuttle flights to the space station and possibly one final servicing call to the Hubble Space Telescope. Before the Columbia accident, NASA expected to fly 28 missions to the station.
The first six missions would test the shuttle and carry smaller pieces -- trusses and solar arrays -- to the station. The seventh, targeted to fly in late 2007, would carry a major piece, the European Space Agency's Columbus laboratory module.
It would immediately be followed by the first of three launches for Japan's Kibo module.
In 2009, with four shuttle flights remaining to finish the outpost, the station should be able to support a six-person crew, the new schedule shows.
The space station has operated with just a two-member crew since the Columbia accident to save on supplies while the shuttle fleet was grounded for repairs. NASA plans to restore the third member to the crew as early as May.
NASA plans to begin flying a new capsule-style spaceship, called the Crew Exploration Vehicle, as early as 2012.