(Reuters) - A U.S. Senate oversight committee unanimously passed a plan on Thursday to postpone retirement of the space shuttle as part of a job-saving compromise to the Obama administration's wish to end NASA's program to return astronauts to the moon.

The NASA plan approved by the Senate Commerce, Science and Transportation Committee supports Obama's call to end the moon-bound Constellation program, currently the human space flight successor to the shuttle program.

But the three-year NASA spending plan passed by the committee adds another shuttle mission to the International Space Station, to be flown next summer or fall, and leaves contracts, equipment and personnel in place in case other flights are needed.

The coming retirement of the space shuttle is imperiling thousands of jobs at the Kennedy Space Center in Florida, as well as jobs in Texas, Alabama and Utah ahead of November's congressional elections.

Currently, NASA has two remaining shuttle flights to complete construction of the $100 billion orbital outpost.

The Senate plan wants NASA to begin work immediately on a new U.S. launch system for future missions beyond Earth's orbit, and while it supports President Barack Obama's proposal to develop commercial space taxis, financing for the venture would be cut sharply.

The plan leaves intact the White House's $19 billion funding request for NASA for the fiscal year beginning on October 1, but replaces the administration's push for new technology initiatives with a mix of programs intended to reduce the amount of time that the United States won't have vehicles to fly astronauts into space.

With the space shuttles retiring, the United States is dependent on Russia for flying people to the station until a commercial firm or new government vehicle is available.

The spending plan also calls for a new heavy-lift launch vehicle and capsule capable of flying astronauts to asteroids and other destinations in deep space.

Both the rocket and the capsule would draw heavily from programs, including the space shuttle and the Constellation moon program, which Obama wants to cancel.

The Senate bill revives several Constellation program components, including a "multipurpose" spacecraft for human travel and a launch vehicle capable of putting at least 70 tonnes into a low orbit around Earth.

Rather than focusing on the moon, the Senate committee bill calls for a new program to be flexible enough to reach different destinations. It directs NASA to begin work on a heavy-lift rocket in 2011, rather than the 2015 time frame proposed by the White House.

The bill cuts Obama's request for $6 billion over five years to develop commercial space-liners to fly astronauts to the station to $1.6 billion over three years. Both plans budget about $3 billion annually to continue the space station and $5 billion annually for science.

(Reporting by Irene Klotz, Editing by Vicki Allen)