Within the next few years, it will be possible to drive across the United States listening to the same radio station, tuning in to the same radio personalities in Maryland, Ohio, Nebraska and California and states in between.

The ads and news breaks may vary with locale, but the songs, chosen by computer research and mass audience analysis, will remain the same.

This morning, a new era in radio programming begins when 150 stations around the country join the new Satellite Music Network's two 24-hour services, Country Coast to Coast and Starstation, beamed off Satcom I.

Network radio, transmitted in bits and pieces over land lines and via tape, has been a big item for the past three or four years, but the satellite networks herald a possible return to the "national radio" that existed in the medium's early decades. In fact, radio could mimic television in leaving its programming to a few major voices with the only local contributions being news breaks and advertising spots.

Other 24-hour (long-form) formats waiting in the wings include Bonneville's beautiful music, Sunbelt's "adult contemporary," Continental's mix of pop and Christian music, an ABC Radio talk show and others from such existing networks as RKO, CBS, NBC and Mutual. And networks new and old will undoubtedly be offering a variety of full formats, all targeted to specific demographics by way of heavenly satellites and earthbound dishes.

"Radio is the creature of technology," says Rick Sklar, program head for ABC Radio Enterprises, which is planning to produce an 18-hour-a-day national talk network as well as a 24-hour music service starting in March. "The impact of television caused it to change originally from a national nighttime entertainment to an around-the-clock medium providing all kinds of services. With the development of FM technology, there were more stations and they became more specialized, going after targeted, special interest audiences."

There currently are more than 9,000 radio stations in the United States, of which only 30 percent are profitable, according to radio consultant Kent Burkhart. Many of those stations already use existing networks and syndicators for portions of their programming; ABC, for instance, has almost 1,800 affiliates to its four existing radio networks (Information, Contemporary, FM and Entertainment; they are now on land lines, but will switch to satellite by 1984). Other stations use consultants who tell them what to play and how to play it to ensure the strong ratings that affect advertising -- the medium's lifeblood. And many stations make out as well as they can under the weight of ever-increasing operating costs, a nationwide talent shortage and a cutthroat competitive environment.

Centralized satellite programming will allow many of these struggling station owners to abolish such jobs as program director, announcer, copy director. One network advertises the economic benefits as "saleable product without out-of-pocket high cash costs and programming resources that build audience, cut costs, improve productivity of personnel and facilities." Which must sound good to a station perpetually in the red. And the advantage of the round-the-clock service is justified by research showing that more than 40 percent of all adults over 18 -- that's 65 million potential customers -- listen to overnight radio.

"A medium-sized station will be able to save $150,000 a year, a small station $60,000 to $75,000," says Burkhart, who is president of Burkhart/Abrams/Michaels/Douglas and Associates, the radio consulting agency that is the major force behind the Satellite Music Network, which has its studios in Chicago and offices in Atlanta. "And larger stations, depending on their talent overhead, can save even more." Should it choose a 24-hour format, a station would actually be able to operate with only an engineer to cue in the local ads ("practically turn-key" one brochure promises). With everything being done by computer, the human element will obviously diminish -- as will the payroll.

The cries of protest against satellite radio have centered on the potential loss of jobs and the possible homogenization of the airwaves. Program directors, who see their jobs threatened, insist that local image and personality are prime ingredients in a station's success and that satellites can't counter that. The satelliters, on the other hand, say that such strength exists only in drive time, and that after that listeners don't really care about the announcer's point of origin as long as the programming is good. And the satellite deejays, personalities who will sound as "alive" as your current favorite even when they are broadcasting from Chicago or Los Angeles, will be careful not to say from where they are broadcasting. Time-zone problems will be solved by keeping announcements simple: "It's 20 past the hour," and so on. "It will expose more people to a higher class of radio," admits one local program director. In fact, the satellite deejays could become national radio stars; most of the current crop are show hosts exposed through syndication.

On the music side, there is the danger that radio will mimic television and seek the lowest common denominator in trying to reach the widest possible audience. Burkhart admits that in choosing its programs, SMN will follow the Burkhart/Abrams pattern of consultancy. "There are some isolated islands; New York City has a music mix of its own that we call an urban music mix. We exclude that from the national sample. When you put the national sample all together, 90 percent of America is in agreement on the current hit product. We don't pay any attention to the 10 percent that's left, we play the 90 percent that's safe."

There currently are no plans by any Washington radio stations to use the satellite networks on any major basis (SMN will be joined in October by Sunbelt and Continental; ABC's talk show is slated for March 1982, and other networks will be announced shortly). Obviously, as syndicators start to use satellites more, program directors will use them as working tools to provide ratings-oriented programming at lower operating costs.

With 35 stations and a highly fragmented market, Washington needs those local controls and flexibility. But across the country, there's a receptive market for networking. Burkhart predicts that in 10 years, 50 percent of the nation's radio stations will be carrying all or part of their programming from satellites. "That leaves 50 percent out there doing their thing. They're the ones that take the risks. We're not crusaders, we're reflectors."

"There was a time when radio was mostly national," adds Sklar. "Movies are a national medium. Nighttime television is a national medium. Radio once was. Cable television is mostly local. These things go back and forth. What counts is entertainment and the quality of programming."