More than a quarter of a century ago, Gene Roddenberry managed to bring a television series he described as "Wagon Train to the Stars" to NBC.

That series, of course, was "Star Trek." And it went on to become a part of American culture that will live on long after its creator, who died Thursday at the age of 70.It's not news that "Star Trek" was never a success during its 1966-69 run on NBC. The network tried to cancel it three times, finally succeeding after just 79 episodes were produced.

And the rest of the story has become part of the legend. How those 79 episodes became wildly popular in syndication. How that popularity spawned an animated series, six movies, a highly rated new live-action TV series ("Star Trek: The Next Generation") a series of best-selling novels and an incredible range of memorabilia.

A recent poll indicated that more than half of all Americans identify themselves as "Star Trek" fans. That's more than 130 million Trekkies or Trekkers in this country alone.

REMEMBRANCE All this from a TV series - full of cheesy special effects in its original incarnation - about a "Wagon Train to the Stars."

There are many theories about the roots of the "Star Trek" phenomenon. America's fascination with space, particularly during the race to the moon in the '60s, undoubtedly had something to with it.

So did the undeniable chemistry among the original cast - William Shatner as Capt. Kirk, Leonard Nimoy as the Vulcan, Mr. Spock, and DeForest Kelley as Dr. McCoy. And that chemistry has been successfully recreated by the newcomers on "The Next Generation."

But the one fundamental factor that makes "Star Trek" so appealing is its inherent optimism. What Roddenberry created back in the mid-1960s was a future that so many of us dream of.

Particularly back in the '60s, we weren't even sure the human race would survive the nuclear age in the latter half of the 20th century. "Star Trek" showed us enlightened humans spreading through the galaxy in the 23rd century.

It showed us a human race in which race was no longer a factor. The white Capt. Kirk served with the Asian Lt. Sulu, the African-American - and female - Lt. Uhura, and even Mr. Spock, the product of a mixed marriage between a human and an alien.

There were still obstacles to overcome and enemies to contend with (including Klingons and Romulans), but man's intellect had led him into a golden age in which poverty, privation and greed had been all but extinguished.

The United Federation of Planets, of which Earth was the primary member, was founded on the principles of democracy, brotherhood and tolerance.

In Roddenberry's universe, man became not what he is, but what he should be.

The original "Star Trek" series dealt with issues almost ignored during its time, and often in a rather heavy-handed way - race relations, prejudice, military escalation, communism, totalitarianism, organized religion, aging, the basic struggle between good and evil, even genetic engineering (before that term had even come into popular use).

Roddenberry's vision, somewhat altered to meet the demands of NBC for an action-filled series in the '60s, reached fruition in "The Next Generation." Capt. Picard and his crew go to every length to avoid firing those phasors Capt. Kirk was so fond of, preferring negotiations to fighting.

Women, who got the short shrift (and the short skirts) in the '60s, are now portrayed as doctors, captains and admirals. Even the opening tag line was changed from "To boldly go where no man has gone before" to "where no one has gone before."

Amid all the adventures, this horse opera in space has had at its core for these past 25 years Roddenberry's undying optimism about the nature of man and his future. And it's because of that optimism that "Star Trek" will live long and prosper even without its spiritual leader.