BATTLESTAR Galactica (ABC). The characters are right out of a Saturday morning cartoon, the dialogue more 1955 than "2001," and the plots drag in everything but the kitchen sinktica, but this costly, noisy, zap-happy sci-fi series produced by John "Star Wars" Dykstra is considered the one guaranteed smithereen hit of the season. It all takes place in a galaxy "far, far away" (sound familiar?) where a human race remarkably like our own finds itself the target of annihilation by the dread Cylons, stainless-steel storm troopers who have purple lightbulbs in their spaceships and nasty red beams where by all that's holdy their eyes should be.

The scrip isss hokum - and sci-fi purists may wince - but this show has everything: It's a family saga, a soap opera, a carnvial for kids and an ongoing blitz of slam-bang special-effects space battles. "Right here, your creeps!" Shouts Capt. Apollo in his best John Wayne manner. "Look out behind you!" yelIs a colleague . . . BLAMM-O! Lorne Greene is in charge of the drifting fleet of wandering, homeless humans, and if the program maintains the momentum of its first episode, nothing will be able to stop it. After a screening of the two-hour foreign theatrical version of the show's three-hour premiere in Hollywood, a little boy summed it all up. "I like all the shooting," he said. (Premieres Sept. 17, 8 p.m.).

Mary (CBS) brings back probably the best-liked little American Mary since Pickford - Tyler Moore, that is - in a weekly hour of mostly sketch comedy featuring a resident cast of supporting bananas with venerable Dick Shawn topping the bunch. Taped in Carol Burnett's old studio at CBS Television City, Moore's hour will include such regular features as "Mary Speaks" (usually about such dubiously hot topics as "what BTU's are") and "Fairfax Alley," named after the street TV City sits on, and in which the cast sits around and comically chews fat.

It's hoped the show can survive without relying on big-name guest stars and without recruiting the gang from Moore's fondly remembered sit-com, though on one episode she will visit the cobwebby old WJM-TV newsroom set and, on the premiere, there'll be a peformance by "The Ed Asner Dancers" - sans Ed Asner, that is (Sept. 24, 8 p.m.).

Kaz (CBS) is one tough cookie of a lawyer, mainly because he's done six years in the slammer himself, which is where he learned law and got his degree. Ron Leibman is a winningly obnoxious rouser in the title role - full name, "Martin Kazinski" - of this snappy and civilized weekly drama, which also features Patrick O'Neal as the rich, stuffy head of the law firm that reluctantly takes Kaz on. Then Kaz starts taking everybody else on. (Sept. 10, 10 p.m.).

Lifeline (NBC) qualifies as the most unusual new series of the year, since its hosptial dramas are played out by real doctors andpatients in doceumentary (or near-documentary) footage. Each show will focus on one doctor and his practice; one can expect happy endings, despite the cries of realisM but also some riveting and compelling footage of fellow people in states of true physical and emotional crisis. Not all survive. (Oct. 8, 10 p.m.). Monday

WKRP in Cincinnati (CBS) takes honors as the brightest and funniest new comedy of the season with the most likable cast besides - especially Gard Sandy as the down-homey buddy-boy who revives a laggardly radio station with new programming, and Howard Hesseman, hilarious as a burnt-out deejay prone to falling asleep into his coffee cup. The show has the same family-of-coworkers, rousing ensemble quality of the old "Mary Tyler Moore Show" and it is, not surprisingly, an MTM productin. (Premieres Sept. 18, 8 p.m.).

People (CBS), from the frivolous and delectable magazine of the same name, will attempt delectable frivolity of its own with three or four weekly features on celebs and non-celebs ostensibly worth knowing. "The important thing to remember," says producer Charlotte Schiff Jones, "is that we are not a news show. We are a people show." An beautiful person Phyllis Geroge is the host. Featured on the premiere: Elizabeth Taylor and Willie Nelson. (Sept. 18, 8:30 p.m.). Tuesday

The Paper Chase (CBS) finds John Houseman recreating his 1974 Oscar winning role as the imperial Professor Charles Kingsfield as a tough eastern law school that eager student John T. Hart (James Stephens) is working, or stumbling, his way through. "You come in here with a skull full of mush, I send you out thinking like a lawyer," roars Kingsfield. The mush will presumably harden as the drama series trods on. (Premieres Sept. 19, 8 p.m.).

Grandpa Goes to Washington (NBC) and the spirit if Will Rogers and "Mr. Smith" - and perhaps even Howard Jarvis - send him jousting against the political establishment. If ever America was ready for a comedy that skewer politicos and the federal government, it must be now, and Jack Albertson makes a dandy and slightly randy old coot, tilting bravely with bureaucratic windmills and greetring strange women with an affectionate, "Will you marry me?" Sue Ann Langdon and Larry Linville (as an aide to the Joint Chiefs of Staff) head the family whose life Gramps invades when his victory in the polls forces him to Washington. (Sept. 19, 8 p.m.).

Taxi (ABC) continues in the crackling character-comedy traditions of blue collar capers like "Barney Miller," though it's been assembled by a pack of expatriates from MTM Enterprises. The series about wiseacre New York cabbies (aren't they all?) will sink or swim on the merits of its cast, which includes whacko "Saturday Night Live" discovery Andy Kaufman, Marilu Henner, dull Judd Hirsch, a very funny short fat man named Danny DeVito, and ex-boxer Tony Danza, who could become a star in the Henry Winkler-John Travolta tradition. (Sept.12, 9:30 p.m.). Wednesday

In the Beginning (CBS), from Norman Lear's production company, pits McLean Stevenson as spoiled and uptight Father Cleary against Priscilla Lopez (who sang "What I Did for Love" in "A Chorus Line") as spacey, trendy Sister Agnes, also known to Cleary as "Sister Mary Jackass." She wants to open a storefront mission for the poor, he wants to stay in his comfy middle-class parish, and the Lear folks insist that "a whole flock" of real priests go over the scripts for possibly offensive jokes. That means they apparently don't mind Sister Agnes saying things like, "Damn, I wish I could swear!" during a moment of pixiesque pique. (Premieres Sept. 20, 8:30 p.m.).

Dick Clark's Live Wednesday (NBC) will specialize in acts that bring back memories of the '50s and '60s as the ageless gatekeeper of American puberty hosts a mostly live variety hour. Such old-timers as Sid Caesar, Milton Berle and Edgar Bergen have already been signed for guest shots along with new-timers like Billy Preston. (Sept. 20, 8 p.m.).

Vegas (ABC) is the stomping roundfor though private eye Dan Tanna (Robert Urich), who is always dripping with danger and gorgeous gals and who will always exist somewhere in the imagination of middle-aged men. (Sept. 20, 10 p.m.). Thursday

Mork and Mindy (ABC) stars one of the brightest new comic talents of the '70s, Robin Williams, as zany, zany Ork from the planet Mork- no it's Mork from the planet Ork - a character introduced last year on "Happy Days" and this year beaming down to earth for his own series, in which he finds himself flipping literally for an earth girl played by Paw Dawber. It's not a new concept - they might have called it "My Favorite Orkan" - but Williams may levitate it into hilarity. (Premieres Sept. 14, 8 p.m.).

W.E.B. (NBC), all about a put-upon woman executive (Pamela Bellwood) and the mythical T.A.B. television network, will be "somewhat autobiographical," concedes series creator and producer Lyn Bolen, which figures since she was herself head of day-time programming at not-so-mythical NBC. There'll be interoffice hanky-panky, corporate derring-do, and lots of boardroom and bedroom shouting matches in the weekly drama. (Sept. 21, 10 p.m.). Friday

The Waverly Wonders (NBC) are a butterfingered basketball team at a midwestern high school, saved from disgrace by Joe Namath as Harry Casey, who is supposed to teach history but prefers a good old romp in the gym. "I hear he scores more off the court than on," smirked the prim lady principal in the show's mechanical pilot, already aired, and the comedy proved pretty prim, too, with Namath a wooden soldier not quite come to life. Time may loosen him up, but the show remains a poor man's "Welcome Back, Kotter." (Sept. 22, 8 p.m.).

Who's Watching the Kids? (NBC) began as "Blansky's Beauties," then became "Legs," then became "Kids" when NBC decided to sanitize its own airwaves and revised this peeping tome. The sit-com is still set in Las Vegas, where a showbiz mom tries to raise her tots to be apple-pie normal in a cheesecake environment. The cast includes Scott Baio, Caren Kaye, Marcia Lewis and John Belushi's litle brother Jim. (Sept. 8:30 p.m.).

Flying High (CBS), the worst new series of the year, stars, in the immortal words of CBS publicity, "three faces new to television drama from the glamorous world of New York modelling" - though it's not so much their faces that are starred - as dipsy, dawdling stewardesses who find romance in the ozone layer. When the pilot for this witless and plotless airbag was shown in late August, it drew more viewers than any other network program that week. (Sept. 29, 10 p.m.).

The Eddie Capra Mysteries (NBC) brign the true whodunit back to television in a style slightly sprightlier than NBC's campy "Ellery Queen." Again, though, the audience is supplied clues as the sleuth, in this case a feisty maverick lawyer, collects them. Vincent Baggetta as Capra and Wendy Phillips as his very close neighbor Lacey Brown established a sweet rapport in the program's already televised pilot show that should help sustain interest even if the mysteries run into plotholes. (Spet. 22, 10 p.m.). Saturday

Apple Pie (ABC), stars Maude's old neighbor Rue McClanahan as a lonely kook who decides the Great Depression would be less depressing if she had a family around. So, whe recruits one through newspaper want ads. period sit-coms are rare enough; this one is set in Kansas City circa 1933 and has McClanahan exclaiming things like, "Well, I'll be the minister's beer mug!" Dabney Coleman, once Mayor Jeeter on "Mary Hartman," is among the inmates of the boarding house and Jack Gilford is hilarious as a blind but blustery old fogey. (Sept. 23, 8:30 p.m.).

The American Girls (CBS) are a two-woman research team for a "60 Minutes" like TV news magazine. They get into lots of scrapes and out of lots of clothes. Priscilla Barnes and Debra Clinger star as the female "Starskyt and Hutch." (Sept. 23, 9 p.m.).

Sword of Justice (NBC) combines the old masked avenger bit with "It Takes a Thief," as Dack Rambo plays a playboy tennis pro who, when shadows fall, sets about foiling crooks so clever that even the feds can't nab them. Bert Rosario has the thankless role of his Puerto Rican sidekick - a kind of Latino Stepin Fetchit who does the dull or dirty work. (Sept. 23, 10 p.m.).

Weekend (NBC), the smartest and sassiest TV magazine ever, doesn't actually become a weekly series until Dec. 2 - a date moved up from the original target, Dec. 10. But the program will be seem monthly in the meantime, starting tonight at 10, with exclusive footage of the British-born "test-tube baby" and other reports. Then "Weekend" will be seen again Thursday, Oct. 12 at 10 p.m. Linda Ellerbee joins the dryest and wryest of all TV journalists, unflappable Lloyd Dobyns, to cohost the program, which executive producer Reuven Frank promises will retain the pungent and pugnacious tone that has made it a haven of sanity and sarcasm in TV news. (Dec. 2, 10 p.m.). Specials, Miniseries

ABC's roster of miniseries productions will be dominated by the early 1979 showing of "Roots: The Next Generations," which will take 14 hours to recount the travails of Kunta Kinte's descendants from 1882 until the present. Produced at a reported three times the $6 million cost of the original "Roots," the saga stars, among others, Georg Stanford Brown, Ja'net Dubois, Henry Fonda, Avon Long and Richard Thomas.

The network will devote six hours each to "Pearl," the story of the days before and after the attack on Pearl Harbor and how it affects three coupls and "Ike" with Roubert Duvall as Dwight D. Eisenhower and Lee Remick as his aide, jeep driver and intimate sideckick, Kay Summersby.

The biggest entertainment special on ABC's drawing board is "Ge's ALL Star Anniversary," a review of the century to celebrate General Electric's founding in 1878, with John Wayne as host to Bob Hope, Suzanne Somers, Red Skelton, Lucille Ball, and, of course, Pat Hingle as Thomas Alva Edison, the role he's played in an outstanding series of corporate commercials.

CBS, which only dipped its toe into the miniseries waters last year - stubbing it painfully on "The Dain Curse" - will expand production with eight hours of "The Word," from an Irving Wallace novel about an illusory "lost gospel"; four hours of "The Pirate," from a piece of trash by Harold Robbins; and adaptations of Brooke Hayward's Hollywood memoir "Haywire" and John Dean's confessional "Blind Ambition," postponed from last year.

Drama specials will include such questionably appetizing dishes as "Dummy," which CBS says concerns "an illiterate, poor black deaf mute (sic) accused of murdering two prostitutes."

Entertainment spectaculars will be highlighted by the Ford 75th Anniversary Special, for which Paul Newman, Joanne Woodward and Tennessee Williams have been signed (and which may find Ethel Merman and Mary Martin recreating their legendary duet from Ford's 50th anniversary special); and "The Star Wars Holiday Special," with C3PO, R2-D2, and other beloved machines.

NBC has high hopes for "Backstairs at the White House," a miniseries at least eight hours long adapted from the memoirs of longtime White House maid Lillian Rogers Parks (to be seen no sooner than February), "Centennial," 25 hours of everything, from history according to James A. Michener and new 6-hour versions of "From Here to Eternity" and James T. Farrell's "Studs Lonigan."

Among NBC's more promising dramatic specials: "Fame," a new play by Arthur Miller; "Return Engagement" starring Elizabeth Taylor and Joseph Bottoms; Joanne Woodward in an adaptation of D.H. Lawrence's "Lady Chatterley's Lover" (unless Prudie Silverman puts the kibosh on that one), and Harvey Korman and Buddy Hackett in "Bud and Lou," the story of the tumultuous but incredibly lucrative partnership between Abbott and Costello.

NBC will also inaugurate a series of occasional original dramas for television under the showcase title "NBC" Theater." First of these, set for Monday, Oct. 9 at 9 p.m., will be "Summer of My German Soldier," with Kristy McNichol and Bruce Davison as a Jewish teenager and a German prisoner of war who fall in love in a small southern town where the German is imprisoned in 1944. Esther Rolle and Michael Constantine also appear in the play by Jane Howard Hammerstein, from a book by Betty Greene.

Two particularly auspicious entertainment specials promised by NBC are a live performance of Rachmaninoff's 3rd piano concerto by pianist Vladimir Horowitz, from Lincoln Center in New York, on Sunday, Sept. 24 at 5 p.m. (the first half of the concert, a collection of short pieces, will not be televised), and a new production of a classic from the earliest years of TV - Gian-Carlo Menotti's fantasy opera "Amahl and the Night Visitors," to be ssen on Christmans Eve.