NASA's internal planning date for the first manned launch of the new Orion spacecraft that will replace the space shuttle after the winged orbiters are retired in 2010 has slipped one year, from September 2013 to September 2014. The new schedule, managers said today, reflects a more realistic assessment of projected funding, contract realities and technical requirements in the absence of any significant additional support from Congress.

The agency's public commitment to initial operations with the Orion spacecraft remains March 2015, nearly five full years after the shuttle Endeavour flies that program's final mission in the spring of 2010. Between the shuttle fleet's retirement and the debut of Orion, U.S. astronauts will be forced to hitch rides to orbit aboard Russian Soyuz spacecraft.

NASA managers, holding out hope they could "close the gap" between shuttle and Orion operations, had been pressing for first launch of a manned Orion capsule in September 2013. But based on a more realistic assessment of projected funding and technical requirements, the date slipped a full year, leaving little hope the gap can, in fact, be narrowed in any significant way.

"We are adhering to our commitment date of March 2015 for initial operating capability," said Doug Cooke, deputy associate administrator of NASA's Exploration Systems Mission Directorate.

"As the program ... content matures, and as we now have contracts in place, we are better able to phase the necessary work within the established budgets," he said during an afternoon teleconference. "At this point, we've been working to an aggressive internal IOC date of September 2013. Basically, we wanted to press this date as hard as we could until we understood in more detail so that we were able to get the earliest possible date.

"With the current understanding and with the mature data we now have, we are shifting that date to September of 2014, which is still an aggressive date against a commitment date of March 2015. We wanted to announce this at this time because this will result in some contract directions and changes and actions and other internal milestone changes in order to align the work within the available budget."

Jeff Hanley, Constellation program manager at the Johnson Space Center in Houston, said even with the slip of the first manned Orion flight to no earlier than September 2014, "Our confidence that the gap will get no worse than five years has actually improved." "This alignment you see us doing is, in fact, to better align schedule with the available dollars," he said. "We had a more aggressive target, the 2013 target, that we set many, many months ago when our total plan and our total understanding of the costs to get to the end, the finish line if you will, was a lot less mature. So this is the product of going through this process of deciding what our requirements are, getting our contracts in place, understanding what the true costs really look like they're going to be."

A first launch in September 2014 "is, in my opinion, very achievable with no additional dollars," he said.

Plans for an unmanned Ares-1 first stage test flight next spring will remain on track, as will a launch abort test. Subsequent milestones likely will slip based on the reassessment.

The Constellation program is made up of manned Orion spacecraft, the shuttle booster-derived Ares-1 rocket that will propel them into low-Earth orbit and the heavy-lift unmanned Ares-5 that ultimately will boost Orion capsules and lunar landers from Earth orbit to the moon.

The program is the result of the 2003 Columbia disaster and a subsequent decision by the Bush administration to complete the international space station and retire the shuttle fleet by the end of fiscal 2010. The money that had gone into supporting those programs will then be funneled into the Constellation program and the shuttle's replacement. The long-range goal is to establish a lunar base of sorts by around 2020.

But the high cost of recovering from Columbia, and the lack of any significant additional funding for Constellation, resulted in a projected five-year gap in the nation's ability to launch astronauts into space. NASA managers and some lawmakers have held out hope for closing that gap and both presidential candidates have expressed support. But given current budget projections, there appears little hope the gap can be significantly reduced even if additional funding ultimately is approved.

"The window of opportunity for us to accelerate Orion is closing, and in fact this summer here, with this realignment of our schedule, has closed," Hanley said. "Now, if new money should become available in the next few months or in the next year, we would certainly do all we could, but it depends on the timing of it, it depends on where we're at with having slowed the program down with the contract actions ... that we'll be taking in the next few weeks. That in itself is a very elaborate, tedious process to go renegotiate contracts based on this schedule."

Said Cooke: "If there were additional money, we would apply it as best we could and we will continue to do everything we can to reduce the gap between shuttle retirement and flying the Ares-1 and Orion."

On a positive note, Hanley said engineers have come up with a possible fix for high vibration levels in the Ares-1 rocket.

"It's a really rather elegant concept of using electromagnetic mass absorbers," he said. "Basically, what they are are big springs at the base of the rocket, either arrayed inside or outside the aft skirt of the first stage. The team has identified a concept, a system that has an active element to it to sense what's going on with the vehicle, the way it's behaving, and actually manipulate those mass absorbers to tune up with the offending oscillations. That looks to be very effective."

The Ares-1 first stage is an extended version of the solid-fuel booster used by the space shuttle. Engineers were concerned early on about potentially excessive vibrations associated with such a large solid-fuel rocket but Hanley said he was confident the problem can be resolved.