The Senate served notice yesterday that while it favors higher defense spending and is willing to buy one more nuclear aircraft carrier, the age of the giant carrier, the age of the giant carriers is ending.

Approving a $36 billion Pentagon money bill by a vote of 87 to 2, the Senate accepted an amendment declaring it national policy to design and build "more survivable, more numerous and less costly" weapons from now on, with cheaper and smaller carriers the case in point.

The amendment was offered by Sen. John C. Culver (D-Iowa), who told the Senate that, in the age of precision missiles, a $2 billion aircraft carrier could be shot "like a duck in a pond."

Chairman John Stennis (D-Miss.) of the Senate Armed Services Committee and Sen. Barry Goldwater (R-Ariz.), key Pentagon allies, were among those who expressed their support of the Culver amendment before it was passed by voice vote.

Stennis said he favored building one more Nimitz-class nuclear carrier, even though President Carter does not want it, but said this fifth nuclear carrier will be the last of the giants as far as he is concerned.

Goldwater said "the day of the carrier has passed," adding that he was "appalled" at the $2.3 billion estimated cost of the Nimitz. He predicted the ship would end up with a price tag of $3 billion.

Sen. John H. Chaffee (R-R.I.), former secretary of the Navy, said that "by drawing the line here that this is it" for building $2 billion carriers the Senate would get "the attention of the Defense Department."

So far, the Navy has built the nuclear-powered carrier Enterprise and has previously won congressional approval for three nuclear carrier of the Nimitz class. The new question is whether a fourth of the Nimitz class should be constructed.

The Carter administration, while not requesting any money in the fiscal 1979 budget for a new carrier, said it would prefer a conventionally powered one if Congress insisted on another large ship.

Administration officials did not mobilize to delete the Nimitz carrier the Senate Armed Services Committee had added to the Pentagon's fiscal 1979 procurement bill passed yesterday, telling congressional anti-carrier forces that they would hold their fire until the appropriations bills were voted.

Carter, in reassessing the congressional support for one more Nimitz, may decide to go along.

The Culver amendment states that even if at some later date the President wants to build a carrier as big as the Nimitz or a conventionally powered one of that same size, he must send Congress "an alternate program of smaller ships" to consider.

Counting the cost of the planes that go aboard a Nimitz as well as the price of the ship itself, together with the ships assigned to protect the carrier, a $30 billion target is presented to an enemy, Culver said in arguing for a change of course in Navy shipbuilding.

The answer to precision weapons, said Culver, is "a sufficient number of smaller aircraft carriers that we can disperse around the world" so any enemy could not get them all in a sudden attack.

The argument that the Pentagon must think smaller and more cheaply in designing and building weapons threaded through the two days of debate on the procurement bill, which authorizes the President to spend $616 million more than he requested for weapons.

"If the attack submarine is not to price itself out of the market similarly itself out of the market similarly to the large carrier," said Chairman Thomas J. McIntrye (D-N.H.) of the Senate Research Subcommittee, "then we must take steps now to reverse the cost growth trend." The Senate Research Subcommittee, "then we must take steps now to reverse the cost growth trend." The Senate Armed Services Committee in its report on the procurement bill directed the Navy to investigate cheaper alternatives to the Los Angeles-class attack submarine, now costing $411 million each.

However, an amendment sponsored by Sen. Gary Hart (D-Colo.) to cancel the Navy F-18 fighter program - a move that Hart said would hasten the switch to smaller carriers - was defeated by a vote of 68 to 22 yesterday.