WASHINGTON, Nov. 24 (Xinhuanet) -- A large deficit in NASA's shuttle program could cause at best a serious delay in the space exploration initiative by President George W. Bush if without planned shuttle flights reduced or a budget addition of billions of US dollars, The Washington Post reported Thursday.

    NASA is negotiating for extra money with the White House to deal with a shortfall that some space experts say could exceed 6 billion dollars from 2006 to 2010, when NASA plans to retire the shuttle for good, the report said.

    The White House, struggling with the costs of Iraq war and Hurricane Katrina, has no intention of giving the green light.

    The deficit came as a result of shuttle safety problems such asinsulation foam loss from the fuel tank during liftoff, which doomed Columbia in Feb. 2003 and recurred in the July launch of Discovery.

    One option for NASA is to reduce the planned 18 shuttle flightsfor international space station and one to service the Hubble Space Telescope, to two per year, or 10 in all, and cut the workforce.

    "NASA Administrator Michael D. Griffin has said that terminating the shuttle program would be just as expensive as keeping it going", it is reported.

    The situation threatens Bush's "Vision for Space Exploration" that was announced in Jan. 2004. Without extra money, experts say,NASA could have trouble developing a new "crew exploration vehicle" by 2014, as originally planned, let alone fulfilling Griffin's wish to fly it by 2012, said the report.

    Bush envisioned to use the shuttle to finish the international space station by 2010, develop the crew exploration vehicle by 2014, return humans to the moon by 2020 and eventually move on to Mars.

    The report said Griffin has earned the trust of the once reluctant Congress, which easily passed the 2006 budget for NASA, for the full 16.5 billion dollars the White House requested. But he cannot allay lawmakers' misgivings about the "gap" in human space travel between the end of shuttle program and the first manned flights of the new exploration vehicle.

    The report said under the budgets projected for the next five years, experts agreed, it will be impossible to complete the planned shuttle missions and finish the new spacecraft by 2012, ormaybe even by 2014.

    One proposal under consideration would keep the shuttle programfully going and let completion of the new spacecraft slip to 2014,if necessary, or even beyond.

    It is also a possibility to fully fund both the shuttle and thenew spacecraft, thus eliminating the entire four-year gap and ensuring a seamless transition to a new era in human space travel,the report said. Enditem