Persis Khambatta thinks that before you know it, bald will be beautiful, shaved heads will be chic, and everyone, just everyone will be lopping off great hanks of hair and showering their heads with great mounds of menthol shaving cream, and if you believe that you also think the Tooth Fairy's check is in the mail.

Which only goes to show how cranked up the great Paramount PR machine must be for the opening of "Star Trek -- The Motion Picture," in which Khambatta plays the role of the bald but beautiful Ilia, navigator from another planet.

Okay, so she shaved her head. Some actresses end up on casting couches, other actresses end up in barber's chairs. You want to make it big, you go the distance.

Actually, no one, but no one, has ever said anything to Persis Khambatta about casting couches. Shaving her head, on the other hand, made a cultural kind of sense.

"In India," she says, "women, when they want to make a wish, say, for the success of their husband, will sometimes sacrifice their hair, because long beautiful hair is very important. So in a way, I guess I sacrificed my hair for my career."

Actually, the hair is back now, hanging rather raggedly in this hour before the hairdresser. The eyes are as dark and limpid as two pools of petroleum, and her mouth is pouty and perfect, the overall effect like that of an . . .

". . . Indian Sophia Loren. That's what they were always calling me. Or Audrey Hepburn. Or Bianca Jagger. Or Gina Lollobrigida. As long as you look like someone who is more known than you, you end up being compared to them. That's why I rather enjoyed being bald, if you can imagine. It gave me more confidence. I felt like I had more of my own identity."

Besides, the wigs that Paramount had promised didn't arrive until seven months after the movie was made, so by then she had grown quite accustomed to high foreheads.

Despite such silliness, Khambatta does not seem like your basic ambitious airhead on the way up. She comes off as bright and self-assured and able to talk articulately about Bombay, where she grew up. She was raised as a Zoroastrian, a religion whose more open-minded approach to women made it easier for her than it might have been for some Indian women to start a modeling career at 13 and become Miss India at 16.

Her father died when she was young, and it was her mother who told the marriage broker to get lost when he came to see about young Persis, who was growing up quite comfortably in a family of merchants and stockbrokers and businessmen.

Not that there haven't been problems. First in London and now in this country, "being an exotic means you're always getting typecast for roles," she says. They seem to relate best to Farah Fawcett."

Or to Jill Clayburgh or Meryl Streep who get the kind of roles that Khambatta would, well, shave her head for. She's willing to wait. In time, "they will create roles like that for me," she says with utter confidence.

If they do, she'll be the first Indian actress to gain real international recognition, though Indians go bananas for movies and make tons of them all the time. "Most Indian women are shaped like the Coca-Cola bottle," she says with the detachment of someone who isn't. "Very busty, very hippy. Besides, in India, movie stars are gods. They wouldn't want to slog through everything you have to here."

Khambatta will. "I'm going to make it to the top," she says sweetly.