Opening day for the Space Technology & Applications International Forum (STAIF-2003) held here allowed for a collective, emotional release of sorrow for Saturday’s space shuttle catastrophe.

However, nuclear engineers are clearly at the ready to proceed on an aggressive, fast-paced agenda that recasts the nation’s ability to investigate the solar system in ways that far outstrip past decades of exploration.

Human spaceflight is not without risk, said Bonnie Dunbar, Assistant Director for University Research and Affairs at NASA’s Johnson Space Center. "I hope you will take some comfort in knowing that this crew [on Columbia] knew that as well. They knew they were moving progress, technology, the nation, and exploration forward," she told the audience.

A veteran space shuttle astronaut, Dunbar said the Columbia crew would be greatly disappointed if the country stepped down from human spaceflight and did not continue to move forward.

"It takes vision and courage to make quantum leaps into the future," Dunbar said.

Those at the STAIF gathering, familiar with NASA’s Prometheus Project, were requested by space agency upper management not to openly elaborate on the strategy for strengthening America’s space nuclear power and propulsion prowess.

That last-minute decision was driven by the Columbia calamity. Numerous approaches, however, that are being set in motion by NASA’s new nuclear space initiative took center stage at STAIF-2003.

"There’s a lot of historical information that we can leverage off of, to give ourselves the best chance possible to succeed this time around," said Michael Houts, Lead, Nuclear Propulsion Group at the NASA Marshall Space Flight Center in Huntsville, Alabama. "We need to be smarter…technically and programmatically," he said.

Houts said an option is to focus on the fastest available, most affordable systems that meet mission requirements.

Alan Newhouse is the newly appointed Director of the Prometheus Project and reached by phone at NASA Headquarters.

One piece of the Prometheus Project is coupled to the Jupiter Icy Moons Orbiter mission – a newly christened undertaking to study Callisto, Ganymede, and Europa. Making use of Nuclear Electric Propulsion (NEP), the probe would jump from moon to moon and study each of those objects in an intensive manner.

This fission-powered probe could be on task in "less than 10 years," Newhouse told SPACE.com, although no firm date is affixed to the newly born mission.

Newhouse said work on NEP, even relying on past progress, will not be easy.

The space-rated nuclear reactor itself, power conversion hardware, large ion engines, as well as handling the voltage level produced onboard the spacecraft are among challenges.

Asked about safety issues in flying nuclear electric propulsion, Newhouse said: "If it isn’t safe, it won’t fly."

The science that can be gained by nuclear-powered spacecraft is impressive, said James Crocker, Vice President of Civil Space, Lockheed Martin Space & Strategic Missiles.

Crocker noted that "99.9 percent of our solar system is unexplorable without nuclear power."

It’s a message we need to more crisply explain to people. The ability to explore…nuclear power is an enabler," Crocker said. "It will revolutionize our capability because of the power that we can bring to bear on these [science] problems.

Be it running deep penetrating radar to study atmospheres of other worlds; looking inside asteroids; sending back to Earth samples of the outer planets; or transmitting huge quantities of data to Earth – spacecraft powered by nuclear energy can open up solar system exploration like never before.

The Prometheus Project "is the game changer for exploration," said Brent Sherwood, the Boeing Company’s Director, Business Development, Exploration & Development of Space (NASA Systems).

"After the system is developed, flown, and proven…there becomes no point in talking about doing it any other way. The world is different after it than before it. That to me is what a game changer is all about," Sherwood said.

NASA’s Gail Allen unveiled details of a new integrated space architecture plan. That blueprint – looking more like a subway map for astronauts, complete with red and orange transportation lines – is not "destination driven," she said. Rather, science is the driver.

The drafting of the space architecture should be completed by June. Seen as an incremental, stepping stone plan, astronauts would be sent to places "where humans need to be in order to pursue the science questions," Allen said. Conversely, how and where best to take advantage of robot skills is part of the space architecture work.

There is an evolving need to utilize the Lagrangian points (L points), far from Earth, Allen said.

Science platforms positioned at various L points are being studied. These large arrays outfitted with sensors would not only look outward to the Sun and beyond, but also stare at Earth. Furthermore, it is not presently clear whether high-skilled robots would be available in time to service the L point science platforms – perhaps a task better handled by humans, Allen added.