April 27, 1986

SENATORS were clearly concerned last week by reports that the National Aeronautics and Space Administration had wasted more than $3.5 billion while cutting or delaying safety expenditures for the space shuttle. But the senators did not seem disturbed enough to block President Reagan's nomination of James C. Fletcher, who presided over the space agency from 1971 to 1977, when much of the waste occurred, to return to his old job as its Administrator.

THE overheated market for homes in the New York suburbs has brought on the return of competitive bidding. It is a phenomenon peculiar to exceptionally strong markets and can affect the customary negotiating strategies of both buyers and sellers. Sellers may receive as many as three or four offers on a house in one day, all near or at the asking price. Under the circumstances, what are the best ways for a seller to handle the situation? Similarly, how can a buyer place himself in the best position to have his offer accepted, assuming he is not prepared to offer significantly more than everyone else?

When you're hot, you're hot. And the Mets stayed red-hot today as they beat the St. Louis Cardinals, 4-3, for the third straight time, for their eighth straight victory over all and for the Cardinals' sixth straight loss. They pounced on Danny Cox in the first inning of his first appearance of the year and swatted out four runs. Then they sat on a lead behind the nearly perfect pitching of Sid Fernandez, who carried a one-hitter into the ninth inning. And finally they were driven to dramatic highs when the Cardinals staged a rousing rally in the ninth: four hits, two runs across, the tying and winning runs on base with only one out.

WHen the curtain descends on Eugene O'Neill's ''Long Day's Journey Into Night,'' as shattering a moment as the American theater knows, Jack Lemmon lets out a moan that sounds soul-deep. It is the final personal stamp in a performance as James Tyrone that promises to stir passions and incite debates much as Dustin Hoffman's Willy Loman did two seasons ago. Similarly, the revival under Jonathan Miller's direction, which opens tomorrow at the Broadhurst, dares to defy the traditional approach to O'Neill, which saw its ultimate expression in the Jose Quintero-Jason Robards revival of ''The Iceman Cometh'' earlier this season. Just as Mr. Hoffman's bantam rooster of a salesman liberated Willy Loman from the hulking, lumbering style of Lee J. Cobb, so Mr. Lemmon's Tyrone stands apart from such previous interpreters as Fredric March, Spencer Tracy, Ralph Richardson and Laurence Olivier. In their hands, Tyrone was the architect of domestic despair - a niggardly, hectoring tyrant largely responsible for one son's alcoholism, another's poor treatment for tuberculosis and his wife's addiction to morphine.

ON a recent Saturday in Westport, the narrow sidewalks of Main Street were teeming as usual with shoppers. They strolled past two rows of trendy stores, including 18 clothing shops, 3 bookstores, 9 restaurants and a specialty pet-food shop. There seemed to be no doubt that Main Street was in a healthy condition. But with local real-estate agents and landlords reporting prime retail space at more than $45 a square foot a year on Main Street - one of the highest of any downtown area in Fairfield County communities of comparable size - some Westport residents are concerned that success will make Main Street so expensive that only national chain stores, not local merchants, will be able afford it.