The National Aeronautics and Space Administration acknowledged yesterday that it improperly asked contractors for lobbying help to save its budget from deep congressional cuts that the agency said could delay major projects and force layoffs across the country.

The agency's office of industry affairs said in a memo dated Aug. 17, "NASA's budget is in trouble on the Hill," and asked marketing representatives to "help us work this problem."

An accompanying position paper detailed the difficulty with the Senate Appropriations Committee and said House members should be "notified of the negative impacts of the Senate's action. However, senators who have the burden of making the earliest decision in this case . . . need to hear your views soon."

The position paper said the Appropriations Committee has cut $818 million in fiscal 1988 funds for NASA and other independent agencies, and the paper said NASA might have to bear most of that cut.

"The question is: Should this one inconsistent action by the Senate committee be permitted to reverse the national effort to restore the United States to its rightful preeminence in space? Is this one action sufficient to default a U.S. leadership role to the Russians and others?" the memo asked.

The memo listed the names of 29 senators to be contacted.

It is a violation of federal law for government agencies to engage in lobbying efforts outside of appearances before congressional committees.

As soon as Administrator James C. Fletcher heard about the memo, according to a NASA source, he sent letters of apology to Senate Appropriations Committee members William Proxmire (D-Wis.) and Jake Garn (R-Utah).

In a statement issued yesterday, after the incident was disclosed by Aviation Week and Space Technology magazine and the Space Commerce Bulletin, NASA said: "We acknowledge there was an improper action by the agency and have taken all steps to remedy the situation."

In its position paper, NASA said the proposed budget cuts could have "a devastating effect" on the agency's plans.

"Programs would have to be canceled, delayed and-or stretched out, and jobs could be lost at NASA centers and at aerospace industry plants across the country," the paper said.

It said the proposed cuts, among other things, could jeopardize the effort to return the space shuttle to flight status next June following the Challenger accident and the start of the $17 billion space station program.

Last week, Proxmire, chairman of the appropriations subcommittee that oversees NASA, said he would "do {his} best to kill the space station project as it is currently configured."

The issue is expected to come before the panel in late September.