Analysts and congressional sources said there is no telling exactly how the loss of shuttle Columbia will affect the agencys spending plans for the foreseeable future. But NASAs 2004 request, made available at 3 p.m. Monday on the space agencys World Wide Web site, reflects a commitment that bas been in place since last year to increase spending on shuttle upgrades with an eye to keeping the vehicle operational until 2025.

NASA spokeswoman Sarah Keegan said it is too early to say how or if NASA might modify its spending request in light of the Columbia accident. Congressional sources said they would anticipate that NASA would send an amended budget request to Capital Hill this spring or earlier summer if substantial changes are needed.

NASAs 2004 request includes $3.968 billion for the space shuttle program, about $700 million more than the shuttle program received for 2002. Prior to Saturday's events the White House had asked Congress to modify NASA's 2003 request to include an additional $470 million to the space shuttle budget, bringing the total to $3.678 billion.

Included in the 2004 request is $1.7 billion the agency had planned to spend over the next five years for a so-called Service Life Extension program of space shuttle upgrades and infrastructure improvements at Kennedy Space Center. The new nomenclature reflects NASA decision last year to try and keep shuttle flying until at least 2020.

Prior to NASA Administrator Sean OKeefe taking the helm, NASA was considering replacing the shuttle with a new generation reusable launch system starting around 2012. NASAs previous upgrade strategy -- and smaller shuttle budgets -- reflected that 2012 planned retirement date.

But NASA signaled in 2002 that it intended to fly five shuttle missions per year and make a larger investment in upgrades intended to improve the overall reliability and safety of the space shuttle system in order to keep it flying well beyond 2012. NASAs renewed commitment to space shuttle upgrades reflected a shift in the agencys assumptions about how much longer it intended to operate the fleet.

Brian Chase, executive director of the National Space Society and a former congressional staffer, said he would expect NASA to continue its investment in space shuttle upgrades, perhaps accelerating the timetable for implementing those upgrades geared toward improving the overall reliability and safety of the vehicle.

At the same time, he said he would not be surprised to see NASA accelerate its investment in the Orbital Space Plane and other launch technologies that could help NASA recover the capability lost with Columbia.

Under NASAs amended 2003 budget plans, the agency announced it intended to spend $2 billion over the next five years alone in order to field an Orbital Space Plane for crew return by 2010. NASAs 2004 request, as it exists today, would continue the investment.

NASAs 2004 request would continue the trend of increasing budget for the space shuttle program Congress approved $3.273 for 2002, about $11 million less than NASA sought, but still $154 million than the program got the year before.

In the request, NASA is also asking Congress to fund several new initiatives, including Project Prometheus, an accelerated nuclear propulsion effort that would culminate around 2010 with a tour of three of Jupiters moons. Prometheus would cost $2 billion over the next five years, an investment that would be made on top of the $1 billion Nuclear Systems Initiative NASA unveiled last year.

The request also seeks $200 million over the next five years to get started on an Optical Communications Initiative that seeks to put an advanced telecommunications satellite around Mars at the end of the decade. Those funds are requested as part of a $4 billion budget for space science. The sought-after $532 million increase over the 2003 space science request would also help NASA get started on the Beyond Einstein Initiative that features two missions: the Laser Interferometer Space Antennae and Constellation-X.

A Human Research Initiative included in the budget would require $300 million over the next five years to accelerate NASAs efforts to learn more about the effects of long duration space flight on humans.

But those initiatives are all part of a budget that was developed under significantly different circumstances than NASA now faces.

Initial opinions varied on how NASAs request would hold up in light of the Columbia accident.

Chase said he would "be surprised if NASA fundamentally changes the nature of its request" or abandon its new ambitions.

"I think in fact you may see a major push to see that those programs [like Prometheus] are preserved in the budget," he said. "Those programs really encapsulate the vision we have for the space program."

A congressional staffer said that while NASA's new initiatives won't be treated as "dead on arrival," they will have to be scrutinized in light of present circumstances.

"Human space flight is the crown jewel of NASA and its on hold right now," the staffer said. "Any other new initiatives are going to take a back seat to assessing the problem we have and remedying it."

Other highlights from the request include:

• $1.552 billion for Earth Science, down from $1.61 billion in the 2003 request.
• $973 million for Biological and Physical Research, up slightly from the 2003 request of $913 million.
• International space station would get $1.7 billion, continuing the trend of declining station budget as assembly nears completion.