TELLURIDE, Colo -- While the cost of space travel remains a hurdle in opening the gates to grander studies of our solar system and beyond, there is no doubt that new technological advances will bring about great change in both robotic and human exploration throughout the 21^st century.

Visionary thinkers and futurists in science, technology, and the arts gathered here at the annual Telluride Tech Festival to paint an optimistic view of what's possible in the coming decades.

Noted science fact/fiction writer, Sir Arthur Clarke took part in the three-day event, held August 8-10. He appeared at the gathering from his home in Sri Lanka via videotape, as well as through a live, land line hook-up from Telluride to Washington, D.C., then relayed via two satellites.

In attendance at the meeting here, and joining Clarke in a special August 9 panel, was Neil Armstrong, the first human to step onto the Moon in July 1969.

"Of course, we will go back one day. I'm sure that the time will come when people are living not only on the Moon, but on Mars and other places," Clarke remarked.

Armstrong congratulated Clarke for a half-century "of making the difficult understandable" to the common person.

"I wish you were here. And I look forward to the day when we can beam you over. I see no reason why that's not possible. We wire flowers all the time," Armstrong told Clarke.

Apollo 11's Armstrong said that some consider anti-gravity as a possible breakthrough in future years.

Clarke responded that research is now underway to explore methods of controlling gravity. While now a line of investigation that is far-out, he admitted, such research is important, he said, "because the payoff could be enormous."

Asked to blueprint what space exploration in the 2025 time frame may be like, Clarke balked on details.

"It's very hard to put a date on anything. You can say things are possible but you're never sure when," Clarke said. He later jokingly added that he advised Orville and Wilbur Wright that "it'll never get off the ground."

"But I'm hoping that the space elevator, which is the shortcut to space, may be built by that time," Clarke said. Cost for a person to ride the elevator up into stationary orbit will be a mere $100, he said.

"When you do have the space elevator, the chief expense of space travel will be for catering in-flight movies, as it does take quite a while to get to stationary orbit. Of course, then you've got to go on by rocket from there. It'll take weeks to get to the other planets," Clarke said.

Clarke said he's confident that the Universe is rife with intelligent life. It would be incredible and inconceivable that we are the only intelligence at this moment of time.

"Of course, the time span is also enormous," Clarke said. "We may have missed many civilizations by millions of years. But I'm sure there are civilizations that are communicating. I hope that one day we will make contact with them."

"The best proof of intelligent life in space is the fact that it hasn't come to Earth," Clarke jested.

The sending of humans to Mars is a top candidate on Clarke's to-do space travel itinerary.

A Mars expedition is likely to be funded by governments, Clarke said, although private enterprise may make such an adventure possible too.

"I'm sure it's going to happen. It is impossible to predict the time scale. If we discovered a cure for AIDS on Mars, we'd be there in five years. But at the present rate of progress it may take 10 or 20 years," Clarke said. "Once you've got the technology, going anywhere is only a matter of time."

Participating in the discussion, Nobel Laureate, Charles Townes, remarked that the public remains stunned about the loss of the Columbia astronauts. "But that will wear off, surely," he said.

The now en route batch of robots headed for Mars are likely to stimulate the public to push harder on space exploration. The incoming results from these Mars missions will indicate how important and how exciting the planet is to the future, Townes said.

Spaceborne telescopes are also helping to spark public excitement about space exploration, Townes said. "We'll need astronauts to go up and take care of telescopes, to adjust them, as they've done for Hubble. They've played a very important role in Hubble. That will provide stimulation and recognition of how important space exploration is," he said.

Clarke told the Tech Festival gathering that he awaits exciting news about Mars to be confirmed in the near future. "I'm keeping my fingers crossed," he said.

"I'm now convinced that Mars doesn't support life…it's infested with life. Some of the recent Mars orbiter pictures confirm completely that Mars is covered with what looks like some kind of vegetation." Clarke said.

"But I would like the geologists to look at some of these patterns and see if any of them could be created by purely tectonic or geological processes, rather than biological ones, the noted writer added.

Asked about any new projects in the works, Clarke said that he's about a third of the way into a new novel called The Last Theorem. "It is still developing. It's going slowly. I only hope that I don't have to change the title to The Lost Theorem."