George Lucas' "Star Wars" has given the American film industry an unexpected, foolproof summer box-office sensation even before the summer release season officially opens. While "Star Wars" continues to set records and create traffic jams at the Uptown, the other summer attractions, which may now be satisfied with moderate success, are assembling in the wings.

Universal's latest Sensurround thriller, "Rollercoaster," which includes extensive location footage at King's Dominion, gets a slight jump by opening this Friday at the Aspen Hill, Fairfax Circle, Jenifer, K-B Langley, Riverdale Plaza and Springfield Mall. George Segal is cast as a worried security man trying to stop extortionist-saboteur Timothy Bottoms. Two sequels aimed at family and juvenile audiences, "For the Love of Benji" and "Sinbad and the Eye of the Tiger," arrive Wednesday, June 15, at dozens of suburban locations.

Following an invitational premiere Wednesday night at the Eisenhower Theater in honor of producer Joseph E. Levine, with Princess Anne of Great Britain and her husband, Capt. Mark Phillips, heading the guest list, the all-star war epic "A Bridge Too Far" begins Thursday, June 16, at the Bradlick Landover Mall, Loew's Embassy, Oxon Hill, Roth's Silver Spring West and Parkway, and Tysons Cinema.

The cast includes such familiar presences as Dirk Bogarde, James Caan, Michael Caine, Sean Connery, Elliott Gould, Gene Hackman, Laurence Oliver, Robert Redford and Liv Ullmann.

Ironically, the most entertaining performance is give by the relatively unfamiliar Edward Fox, who played the title role in "The Day of the Jackal" and makes a wonderfully dashing Gen. Brian Horrocks in "Bridge."

The movie version of Peter Benchley's "The Deep" is set for Friday, June 17, at the ABC Drive-In, Aspen Hill, Cinema 7, Jenifer, K-B Goergetown Square, K-B Silver, New Carrollton, Springfield Cinema and Tysons 1. Robert Shaw, Nick Nolte and Jacqueline Bisset appear as the trio of treasure divers menaced by a Caribbean gangster played by Lou Gossett.

"The Heretic," John Boorman's sequal to "The Exorcist," and "The Other Side of Midnight" also open on June 17.The former, which co-stars Richard Burton, Louise Fletcher, Max von Sydow, Linda Blair and James Earl Jones (who may also be heard as the voice of the renegade knight, Darth Vader, in "Star Wars"), will play the K-B Fine Arts, Bethesda and Crystal, plus a unit each of the Carrollton complex and the Lincoln. "Midnight," a film version of Sidney Sheldon's gaudy romantic triangle in the Jacqueline Susann tradition, co-stars Susan Sarandon, Marie-France Pisier (the flightly wife in "Cousin, Cousin") and John Beck and has been booked at the Annandale, Beacon Mall, Carrollton, Loehmann's Plaza and White Flint.

William Friedkin's "Sorcerer" and the Disney studio's new animated feature "The Rescuers" are scheduled to open Friday, June 24, along with the Japanese "In the Realm of the Senses," moved back a week from a previously announced starting date at the K-B Cerberus and Janus. "The Rescuers" will also have a world invitational premiere at the American Film Institute Theater Sunday, June 19, at 6 p.m., with veteran animators Woolie Reitherman, Frank Thomas and Ollie Johnston appearing.

Martin Scorsese's "New York, New York," opening Wednesday, June 29, at the Avalon 1, is the last of the potential June blockbusters. "One on One," a sports melodrama with Robby Benson as a naive prep basketball star trying to adjust to a high-pressure college athletic environment, is scheduled to begin a multiple booking on June 29.