Celestial chocolate chip chit-chat in New York

In a city where new food fads rise and fall with meteoric speed, one chocolate chip cookie is providing a note of whimsy to jaded Manhattanites and their palates.

It's Alpha Chips - cookies sold from bicycles that look like spaceships, by vendors dressed as celestial pilots. Only seven weeks old, the cookie sales are causing quite a stir on the over-vendored streets of New York.

Business has quadrupled, and the owners are getting ready to crank out more dough.

The big draw is the ''rocketships,'' which look like something out of a comic book. They're black bikes with two egg-shaped white pouches mounted on the wheels. The pouches contain up to 250 bags of cookies. The company logo, a red lightning bolt, zigzags out of the rear pouch.

While the cookies (made with natural ingredients, according to the company) are fairly standard, the marketing concept is extraterrestrial.

''Get your Alpha Chips - the cookie that asks the question,'' hollers Shep Hunter, an ''Alphaman'' working late one Friday night in the heart of Greenwich Village. Clad in a white aviator's uniform with a red and silver cape, white cap , and red wrestler's shoes, he and his Rocketship stop onlookers by the dozens.

Hidden in each bag of cookies is a piece of paper with a question on it. The questions are, to say the least, bizarre: ''Who are you?'' ''Do you speak humanese?'' ''Who are we?'' and ''How about Spanish lessons?'' The nonsensical queries, which change every day, are meant to spark conversations.

''We want this to be a dialogue on the streets of New York. We want to break down superficial barriers between people, get them to talk,'' says Costa Mantis, who originated Alpha Chip Inc. about six months ago.

And the gimmick does get people talking. A volley of friendly questions are fired at Mr. Hunter: ''How'd you do these bikes?'' ''Does each bag contain a different question?'' ''How many cookies do the bags hold?'' (A ''baby bag'' contains seven cookies, a ''mama bag'' holds 14, and a ''papa bag,'' 28.)

Mr. Mantis, a sculptor, writer, and filmmaker who also likes to bake, recounts how a friend urged him to sell his chocolate chip cookies:

'' 'How about from a bike?' she said.

''I said, 'Only if it looks like a rocketship.' ''

That friend, Justine Woolman, became a partner, and six months later, the pair now employs five Alphamen (including one woman) and five bakers. Mantis hired a modelmaker to build the plastic pouches, chose the especially sturdy bikes, and started to bake.

The project is not all whimsy. Mantis is serious when he says his goal is to ''set an example of responsible capitalism.'' One way he does this is to donate unsold cookies to charities.

The company bulletin board is covered with warm thank-you letters from such grateful recipients as the Bowery Mission and Children's Aid Society.

Alpha's owners also want to create working conditions for their employees that reflect the same humanitarian spirit. A profit-sharing plan is in the works. The spacious white bakery in New York's garment district is homey, with lots of sun, plants, and music, and employees do calisthenics together on the roof before their shifts.

''Like astronauts, we have to be in good shape,'' says one Alphaman, leaping on his Alphaship to join the phalanx of his comrades zipping down the crowded New York streets to spread more cheer - and cookies.