NASA's 2004 budget request, released Monday and overshadowed by the Columbia disaster, represents strong support for space science. It also shows hints of an elevated commitment to Mars both as a science target and a place NASA wants to eventually send humans.

For the moment, space science has taken a backseat to the shuttle investigation, within NASA and among scientists, politicians and the public. Researchers acknowledge and appreciate that it could take many months for experiments aboard shuttles to get back on track.

NASA officials say it is too early to predict whether the budget might be adjusted. In a statement released Wednesday afternoon, however, the agency reaffirmed its commitment to human spaceflight and hinted at putting humans on another world:

"NASA remains committed to the pursuit of science in space, knowing that the unique environment offers something never before achievable in the history of humankind: a glimpse of what our life -- what nature itself -- might be like in a world with a different level of gravity."

Mars is by far the most logical place to have that glimpse. Details in the budget show the statement is not idle dreaming.

The 2004 budget request was worked out with White House participation in the weeks prior to Columbia's breakup. It totals $15.469 billion, a $469 million increase over the 2003 request. Within that, $4 billion is earmarked for space science, a $532 million increase over the 2003 space science request.

"The budget submitted is very favorable for science," Friedman said.

The most ambitious new initiative in the 2004 request is Project Prometheus, a proposed $2 billion investment in nuclear propulsion research that would lead to a tour of three of Jupiters moons starting around 2010.

While the Voyager and Galileo missions learned a lot about Jupiter's moons, secrets abound. Most scientists suspect Europa, one of the four largest Jovian satellites, harbors a liquid ocean under its frozen shell. It is among the best places off Earth to look for possible microbial life, along with Mars.

"There's an incredible amount to learn there," Friedman said of the moons.

He warns that the mission probably won't be mounted in NASA's optimistic time frame -- by 2010 -- but that that should not deter the planning or the investment.

An Optical Communications Initiative in the 2004 budget would put a telecommunications satellite in orbit around Mars toward the end of this decade. The cost: $200 million.

Right now, two spacecraft orbit the Red Planet. A pair of surface rovers is planned for launch in 2004. As these and other planned robotic missions become more sophisticated, they generate more data. Getting the images and other bytes of information back to Earth will increasingly become a limiting factor to overall mission planning and success.

A communications satellite would boost transmission capabilities and support not just broad research on Mars, but also efforts intended to pave the way for the first group of people.

For example, studying the harsh radiation environment of Mars is seen as critical to preparing for any possible human mission. And if a crew goes there, among their primary tasks would be to search for life or signs of past life. In fact, many scientists think a thorough survey of Mars, and the discovery of life if it exists there, can't be done by robots.

Robotic investigations are also important to find possible sources of water, which might harbor life and which would prove invaluable to supporting a team of Mars scientists.

Before anyone goes to Mars, more must also be learned about how the human body reacts to months in space, experts say.

To that end, a Human Research Initiative in the 2004 budget would spend $300 million over five years to accelerate efforts to understand effects of spaceflight on the body during trips of 100 days or more. A journey to Mars would take months each way.

Friedman, a proponent of eventually sending humans to Mars, said these latter two programs represent a remarkable commitment to the Red Planet.

Many space industry watchers feared that NASA's new chief, Sean O'Keefe, would be bad for science. O'Keefe was selected by President George Bush to do a better job managing the space agency's money.

"Here's this new administrator who we all feared was nothing more than a bean counter and he has found that the future of NASA is science and exploration, and he's willing to make a commitment for it," Friedman said. "I feel good."

O'Keefe faces tough weeks and months ahead. But almost no one in the space community thinks Columbia spells an end to human space flight. Friedman and others say disasters like Challenger and Columbia can actually serve to regalvanize commitment for human space flight. Even the families of the Columbia astronauts expressed this sentiment.

"Although we grieve deeply, as do the families of Apollo 1 and Challenger before us, the bold exploration of space must go on," the families said in a joint statement released by NASA.

Bolder initiatives may be the most logical next step for NASA. Clearly spaceflight has lost its public allure, as shuttle astronauts toil in relative anonymity unless something dreadful happens. Space travel, many insiders believe, needs a bigger and more exciting goal.

"We've always seen humans going to other worlds as the endpoint, the rationale for the spaceflight program," Friedman said.

That does not mean now is the time to push for a decision about a crewed Mars mission, however.

Friedman notes that bold exploration is typically fueled by political need. The Apollo program is an obvious example, a reaction to the Soviet Union's space efforts during the Cold War. And the space station languished as an idea, Friedman says, until a purpose came along -- cooperation with Russia to foster an international spirit.

"A human mission to Mars also needs to serve a national and maybe an international purpose," Friedman said.

And what might that be? He lists a host of possibilities, putting international cooperation at or near the top. But there are other motivations, including giving America a sense of purpose, spurring industry to action, and providing vision for young people.

John Charles, who works at NASA's Johnson Space Center and is a vocal proponent of human spaceflight, doubts that Columbia will spell the end of the shuttle program or other human spaceflight initiatives. But he thinks it is premature to spend much time discussing it right now.

Beyond the immediate need to focus on the Columbia investigation, Charles cites the poor economy and potential conflict with Iraq as possible important distractions. He notes that it took about a decade to fully recover from the Challenger disaster and put a human-to-Mars mission on the table of serious discussion within NASA.

There is plenty relating to human spaceflight that must be discussed, however, and now. Perhaps now more than ever, the discussion will turn from whether people should leave the planet to what they should do when they risk their lives in this manner.

"I hope we will see a focus on whatever we should be doing with people in space," as Charles put it.

Meanwhile, scientists are eager for experiments to be resumed aboard shuttle flights and the on the space station. They, too, realize that for now decisions are somewhat out of their hands.

Stein Sture, a University of Colorado researcher who lost a portion of the results of an experiment he had aboard Columbia, said it might take two years for science research aboard shuttles to get back on track.

"While the future of space-based science missions is mainly in the hands of politicians, and NASA officials, in that order, I believe that the science community can impact or influence the future course by carefully stating their case and developing exciting and meaningful science experiments," Sture said.

University of Michigan aerospace engineer Gerard Faeth also had an experiment aboard Columbia. He and other researchers typically invest months and even years in preparing experiments that can only be done in a weightless environment. Most of the experiments aboard Columbia, particularly those involving specimens and samples, were lost, according to a NASA statement Wednesday. But the bulk of Faeth's data was downloaded before the disaster.

"Even if I had lost everything, however, it would still be worth it for me to undertake the time and effort to repeat the experiments during future spacecraft missions," Faeth said.

Critics say experiments could be done on automated flights. But Faeth said that for some projects, the "flexible capabilities of human beings is very difficult to match with robots. Thus, for the kind of experimentation carried out by the NASA's Office of Biological and Physical Research, astronauts working in the shirt-sleeved environments of laboratories in space will be needed in the future."

Faeth has worked with NASA since 1967. He said the space agency and Congress are receptive to the needs of scientists.

"This does not mean that our specific recommendations can be accommodated all the time," Faeth said. "Our voices are listened to, however, and are acted upon when our arguments are compelling and can be accommodated within the funds and manpower available to NASA."