Though gaping holes remain in the official accounts of last week's unsuccessful attempt to rescue American hostages in Iran, there is no immediate prospect that Congress or the country will be given additional information that would allow for an independent assessment of the plan.

In the first hours after the raid was announced, many members of Congress expressed consternation mixed with curiosity about what the administration had been planning to do. A number of members pledged to extract the full story. But these early demands for fuller information have quickly subsided.

Relevant congressional committees, including the intelligence committees, have yet to receive a briefing on what the rescue plan would have entailed had it not been aborted after its first stage. Some members are angry about this, but many others seem willing to let the issue lie, and no congressional committee is now planning hearings that could lead to substantial new public disclosures.

The desirability of further public disclosure has been hotly debated behind the scenes on Capitol Hill. The Senate Foreign Relations Committee discussed the issue in a closed session Tuesday, and decided that its initial hearings on the rescue mission should not involve requests for further specific details.

One member of Foreign Relations, who asked that he not be named, said he felt it wasn't necessary to expose the plan further, because "there's no chance" that the Carter administration would try military action again in the wake of last week's failed effort.

Another committee source said the members were reluctant to expose information that could endanger the lives of the hostages or of others -- for example, possible Iranian collaborators -- who were in on or part of the plan. e

Rep. Samuel S. Stratton (D.N.Y.), a key member of the House Armed Services Committee, said yesterday he had no interest in further revelations. s"I don't think we ought to hack the whole thing over in public now because this would reveal whatever tricks we had up our sleeves," Stratton said.

President Carter raised one of many unanswered questions at his news conference Tuesday night, when he said the outcome would have been desirable "had the operation been successful, or even had it been concluded without complete success."

Secretary of State Cyrus R. Vance's resignation over the raid has caused some, including some of his former assistants, to ask whether those who planned the operation envisaged a certain number of American and/or Iranian casualties. Several officials speculated privately that Vance would have opposed a plan he thought was likely to end in casualties that would have created problems both in future American-Iranian relations, and in U.S. dealings with other Persian Gulf states.

The precise reasons for Vance's resignation are themselves a mystery. Whether he balked at aspects of the rescue plan that are public knowledge, or at other aspects of it that are still secret, is not known.

Vance was known to believe that the holding of American hostages was not in itself a threat to the national security of the United States. But there are strong hints that he felt the execution of the rescue plan could create a new situation that could endanger vital American interests.

One question that no administration official has publicly addressed is what would have been done if the rescue operation had failed at a later stage, resulting in the death or capture of all the rescuers and all the hostages. Would the United States then have declared war on Iran?Or done nothing? Or what?

Carter and Defense Secretary Harold Brown have both said that rescuing the hostages from the American embassy would have been relatively easy. As Carter put it Tuesday night:

"There's a general consensus, with which I think no one disagrees, that the actual rescue operation would have been the easiest of the three phases: the most difficult the intrusion into Iran and the placement of those forces, and the second most difficult, the actual extraction of our hostages and men from Iran after the rescue itself from the compound."

How this "consensus" developed and who shared in it remain to be learned.

Perhaps the most basic unanswered question was one raised last Friday by Sen. Henry M. Jackson (D.-Wash.). He asked if it was "a mission that could be carried out with a reasonable prospect of success?"

The chairman of the Joint Chiefs of Staff, Gen. David C. Jones, initially endorsed the plan as "militarily feasible," and said at a press conference Tuesday that it had "a very good chance of success." Numerous members of Congress have noted that when they earlier asked defense and intelligence officials if a rescue mission were possible, the answer was invariably, "no."

Jones explained the change as "an evolutionary process" that included these elements:

"Initially insurmountable problems, and then I would say in early March a growing confidence, but not to the point of saying it had a good chance of success. We finally came up in early to mid April period when we looked at it and had exercised and came down to the conclusion that it was not only militarily feasible but had a very good chance of success."

What had changed to make insurmountable problems surmountable?Neither Jones nor any administration official has offered an answer.