WASHINGTON - Long journeys of flesh and bone astronauts might become a thing of the past. Human space travel in the 21^st century could be, quite literally, an out-of-body experience.

It sounds like New Age meets the Space Age. But one sociologist argues that uploading digital representations of our personalities and behavior into the cosmos rather than in-person star trekking is a form of space transportation worth thinking about.

William Sims Bainbridge says there are several new data points to consider. He argued his case recently at a symposium on the past 40 years of human space exploration and beyond, organized here by George Washington University's Space Policy Institute.

In his talk, Bainbridge "revisited" the spaceflight revolution, pointing out:

• No launch system breakthroughs can be expected soon in the field of space technology;
• Space industrialization is unimportant for post-industrial society;
• Fertility collapses in advanced nations remove population pressures for space colonization;
• Opinion polls show no growth in support for space program over the past 15 years; and
• The "space movement" has little influence, even as conventional space support groups are respectable. And "space religions" -- like Heavens Gate, The Solar Temple, or The Raelian Movement -- have been scorned and unpredictable.

Bainbridge said he concludes that great progress cannot be achieved in space without radical ideas, motivations and actions of a new spaceflight social movement.

To re-energize space progress, Bainbridge said that a "wholly new radical movement" might be required. That movement requires embracing new technology serving old and new motivations, he said.

Several blossoming fields in science and technology, while seemingly remote to astronautics, can give space exploration a new edge, Bainbridge said. Specifically, these disciplines are cognitive neural science, genetic engineering, nanotechnology and information systems, he said.

A melding of such powerful tools, Bainbridge said, may allow the founding of a cosmic civilization, a possibility that does not require flying living human bodies and all the necessities of life to other planets. By applying that diverse tool kit, we can overcome death. The gradual merging of human beings with their computers over the next century gives rise to the prospect of interstellar immortality, he said.

The technology already exists to start archiving personalities, albeit at low fidelity. We can begin now to make digital, audio/visual copies of a person's perceptions, speech and behavior. In years to come, the ability to reanimate human personalities at ever-higher fidelity is a sure bet, Bainbridge said.

That archive is what Bainbridge, author of the seminal work in the mid-1970s, The Spaceflight Revolution, calls Starbase. "Only a goal as valuable as eternal life can motivate investment in substantial scientific infrastructure on the Moon or Mars," Bainbridge said.

Starbase modules, filled with archived but active personalities of crew and colonists, could also make the first interstellar excursions. On their arrival, the crews need not waste time setting up terraforming operations. Rather, the colonists would adapt and thrive in whatever environment they are dealt. Follow-on waves of colonists can be dispatched as "radioed datafiles" across interstellar space, Bainbridge said.

In future centuries, Starbase archives sent throughout the galaxy can be resurrected into robots, clones or cyborgs, Bainbridge said.

By offering the stars to people living today, the second wave of the spaceflight movement would be spurred into being, Bainbridge said. The future demands a powerful, motivational force to create interplanetary and interstellar civilizations, he said, and a new spaceflight social movement can get us moving again.

But there are a few worrisome signs that could short-circuit these ideas.

Moves to prohibit human reproductive cloning, attacks on advanced forms of artificial intelligence, android robots, genetic engineering, and actions to ban some forms of nanotechnology -- this kind of talk heard in various countries "terrifies rather than pleases me," Bainbridge said.

Bainbridge freely admits that his ideas may be too radical for some.

However, NASA itself has started to wrestle with the ethics of giving birth to "life-like" technologies and "living" systems.

Samuel Venneri, who heads NASA's Office of Aerospace Technology, sees up and down sides to the merging of nanotechnology with biology and information technology. He notes in a recent National Science Foundation report on the social implications of nanoscience and nanotechnology that "we will be building systems that become more and more 'life-like' and which interact with and support living systems at the cellular level."

On the other hand, Venneri added, life-like technology and systems are actually living systems, and that systems designed to interact with humans in a human-like manner might be viewed as being "too human."

"In the past, this has been the domain of science fiction," Venneri said. "In the foreseeable future, it could become reality. Our view at NASA is to be pro-active in developing ethical standards to make clear that we understand the accepted boundaries between true 'life sciences' and 'life-like' science," he said.

When pondering the vast distances between stars, experts point out that even a short-duration interstellar voyage might take centuries. "This might not bother an automated probe, but could cause problems for humans," said astro-psychologist, Albert Harrison, at the University of California, Davis.

In his new book, Spacefaring - The Human Dimension, Harrison cites several proposals by deep space thinkers that question the need for human migration to the stars. That includes hurling starbound super-powerful computers that are surrogate brains, packed with personality, a sense of self, memory, and other psychological qualities.

"The beauty of this, if it worked, is that there would be no need for life support as we normally think of it," Harrison said. Star-leaping clones of the human mind would make the voyage, long after the physical bodies they represented had perished, he said.

Yet another popular idea, Harrison recounts, is merely sending a probe filled with genetic codes from Earth, along with a way to cultivate that life upon arrival. Eventually, intelligent life forms would begin to develop. This approach allows seeding life throughout the galaxy without the messy drudgery of protracted human voyaging, he notes.

"There are many conceivable paths to interstellar migration, and the ones that we actually will tread, if any, remain to be seen," Harrison concludes.