At 2 o'clock this morning, somewhat to the consternation of the folks trying to sleep in the neighboring tent at Jetty Park, Susan Treadwell was rewinding a tape of The Rascals' "Mustang Sally" and getting ready to play it for the 27th consecutive time.

Overlook for the moment the perhaps salient fact that Treadwell had consumed a dozen bottles of Heineken in the past four or five hours, and was behaving not unlike any college kid just done with exams and out on a bender; no, the important point is that Susan Treadwell, a student at Embry-Riddle Aeronautical University in Daytona Beach, is part of a huge group of women who have gathered here to cheer on Sally Ride, the first American woman to be chosen for space travel.

Treadwell, who is camping out with two other women who share her interest in aviation, was dancing around in front of their tent. Every time The Rascals sing "Ride, Sally, Ride," Treadwell waved her Heineken above her head. "This is a great day for women," Treadwell said, adding that her decision to attend the nation's major civilian aeronautics institution was prompted partly by NASA's 1978 selection of its first female astronauts. "It's about time we got to go along."

The inclusion of the first woman on a U.S. space shot (the Soviets have already done it twice in two decades) has overshadowed all other aspects of the six-day flight of the space shuttle Challenger. Even NASA, which traditionally has tended to downplay the significance of women in space, decided to invite about 600 women, including Jane Fonda, Gloria Steinem, Anna Chennault, Liz Carpenter, and two other women astronauts, Rhea Seddon and Bonnie Dunbar, to a prelaunch reception.

"The reception is an attempt, in a tasteful way, to say that we understand that this is a milestone day in the space program," said Brian Duff, NASA's director of public affairs. "We tried to invite a wide range of women who have made major contributions to the country.

"NASA happens to sit where epochal events have a tendency to happen, and we have a charge to disseminate this information. Some of the people in the women's movement think that the space program is dominated by gray old men, and Sally is proving that not to be true. It's really a cultural fallout of the last generation, and we want to get the word out that things are changing.

"I'm particularly pleased that Jane Fonda is coming; she's considered to be a role model by a lot of young women. She could certainly pass the physical tests required to become an astronaut."

Perhaps, but maybe lacking a bit in the stamina department. "She's taking a nap now," said her husband Tom Hayden, who did show up at the reception last night. "We were really jet-lagged and the kids went to Epcot and Jane's sleeping."

But Hayden was quick to proffer his analysis of Ride's flight, claiming that after the launch, which he said his wife would attend, "every little girl in America will think it's normal to endure and excel in the space program. This will encourage them to aspire not just to their equal share of civil rights, but also to equal participation in high-tech industries in the future."

Steinem, an editor of Ms. magazine, said she was here half as a journalist and half as a representative of the women's movement. Ride's flight "means that 24 years of unrelenting efforts to get NASA to drop their sex barrier has finally worked," Steinem said. "We brought Jean Hart along to make sure history hasn't been forgotten."

Hart, the widow of Michigan senator Philip A. Hart, was one of 30 women who underwent the same testing given the seven Mercury astronauts at the Lovelace Clinic in Albuquerque.

"Thirteen of us passed the test," Hart said, "and when we were ready for the next phase of testing, NASA arbitrarily decided that we had to be qualified to fly military jets, which excluded all of us. According to Dr. Stanley C. White, one of the original NASA doctors at Lovelace, the decision about jets was made before the tests were given. It got me angry enough to become a real feminist.

"Fortunately, NASA has undergone some terrific changes. Now there will be some astronaut role models for little girls."

Among the guests at the reception was presidential aide Faith Ryan Whittlesey, who read a message from President Reagan:

"Nancy and I both send our warmest congratulations to the NASA team who worked so hard to make this day possible and our prayers to Commander Bob Crippen and his crew--Rick Hauck, John Fabian, Sally Ride and Norm Thagard. May they have a smooth trip and a safe return. And may the force be with them."

In this same spirit of Hollywood Americana, John Denver was on hand to sing a few songs and say that "space, like music, truly brings people together."

Maryland Rep. Beverly B. Byron said, "It's amazing to me to see eight of 20 women members of Congress here. But I don't see this as a big thing for women; I see it as a person doing a job that she's qualified to do. I don't believe in quotas and things."

While many of the spectators already gathered here are effusive in their praise of Sally Ride, these sentiments are not quite universal. At the Copacabana Coiffeurs beauty salon this morning, Stella Peterson was vociferous in criticizing Ride.

"I was very upset at one of the things she said in her press conference," Peterson said. "Somebody asked her if she was looking forward to having children and she said she wouldn't answer that question. Well, anytime you have a woman who's more interested in riding a rocket than in being a mother, you have a country that's in big trouble.

"I've lived around here since before they fired off the first rocket, and, believe me, I know what most of these astronauts are like, and I don't think it's any kind of a life for a lady to want to duplicate."

Next door at the Ron John Surf Shop--"the largest surf shop in the world"--Cindy Garfield, a 19-year-old University of Miami student from New York City, took issue with Peterson's ideas: "More than half of the population of this country is female, and there's no reason that half of the astronauts shouldn't be women."

A woman behind the counter at a 7-Eleven in nearby Titusville added, "She's not just going up there like everybody else, but she's bringing the shuttle right back here." (This is the first shuttle flight scheduled to return to the Kennedy Space Center for its landing.)

The Brevard County Sheriff's Department expects at least half a million spectators to line the beaches here Saturday morning to watch the shuttle climb toward its orbit. "It's possible we'll have as many as a million people," said Maude LaPlante of the sheriff's department. If that happens, it will be the largest crowd gathered here since the flight of Apollo 14.

All of this because they put a woman in the cockpit.

"I wouldn't miss Sally for anything," said Mary Peele of Clewiston, Fla., a veteran space shot watcher who's been camped out since Wednesday waiting for the flight. "Isn't it wonderful?"

Maybe.

Or perhaps as Ride herself said at a news conference May 24:

"I think that maybe it's too bad that our society isn't further along, and that this is such a big deal."