One of the best voices in science fiction has passed away.

The hallmark of a truly great performer isn't that you immediately recognize his face, it's that you recognize his voice. And, within an instant of hearing it, you'll always know Michael Ansara's voice, even if his face isn't there to go along with it.

Science fiction fans know him for so many great performances -- he was the Klingon, Kang, on three separate Star Trek series, Kane on Buck Rogers, and Mr. Freeze for the Batman Animated Series. He played so many roles between 1944 and 2001 that it's hard to imagine how he was able to successfully inhabit so many.

Long before we knew him, though, Michael Ansara was born in Syria, before emigrating with his parents to the United States at the age of 2. In Lowell, Mass., he was a shy boy who had originally thought he'd be a physician. It was acting lessons that brought that boy out of his shell and helped him realize he had another destiny.

It wouldn't be easy. Acting never is. He was relegated to being a bit player mostly from the '40s and more than halfway through the '50s. He was typecast because of his dark skin and played mostly Native American roles.

It was through that particular stereotype that Ansara found his first standout role, as Cochise on the popular western Broken Arrow. He'd take on another Native American character, Deputy U.S. Marshal Sam Buckhart, in Law of the Plainsman.

The 1960s would afford Ansara the chance to break into sci-fi with roles on Outer Limits, Voyage to the Bottom of the Sea, Lost in Space and Time Tunnel. How lucky for him (and for all of us) that this path led him to discover the Klingon Dahar Master Kang. He faced off against Capt. James T. Kirk himself in the Trek classic Day of the Dove. The struggle between these two titans cemented Ansara and Kang as one of the great characters in Trek, if not all science fiction. Kang was so popular that Ansara would reprise the role on Deep Space Nine and Voyager, making him one of a select few performers to feature on three different Star Trek shows.

It was also during this time that he would marry Barbara Eden, star of I Dream of Jeannie. The two would have one child together, son Matthew.

Ansara snuck back behind the limelight again, flitting in and out of the many cop dramas that typified 1970s television. Naturally, we remember him for playing the sympathetic antagonist, Kane, on Buck Rogers in the 25th Century. It was sadly also during this time that his marriage to Eden came to an end. A few short years later, Ansara would begin again by marrying Beverly Kushida. This marriage would last.

Life has a funny way of turning around on a man. The '80s didn't bring anything substantial in the way of major roles, but the '90s would see Ansara return to Kang and, more importantly, they would find him playing one of the most richly complex villains in all of fiction -- Mr. Freeze.

For every fan of TV and film, there is a role for which a performer becomes most known, a part that it seems he was born to play. The very first time I heard Ansara's voice, it came from the mouth of Victor Fries. From that moment on, the two men, one fictional, one real, were inexorably linked.

And, indeed, Mr. Freeze became the one role Ansara would continually return to between 1992 and 2001. It would be the last role he would play. 2001 was also the year Ansara's son, Michael, passed away from a drug overdose.

It's not hard to imagine a man wanting to shy away from fame after the death of his son. The tragedy of Mr. Freeze, a man unable to save the one person he loves most, trapped forever in an unfeeling prison of ice, suddenly feels all too familiar.

And now, in a way that is much more final, Michael Ansara's deep and moving voice is silenced after battling with prolonged illness. Michael Ansara died July 31 at his home in Calabasas, Calif. He is survived by his wife, Beverly, his sister Rose, his niece Michelle, and his nephew Michael John.

He is also survived by every role he ever played, every character he ever inhabited. And in that way his voice endures, eternal, even if the man is not.