The presidential commission investigating the Challenger accident has concluded that NASA officials did not intentionally destroy documents on the shuttle disaster and that it is "reasonably satisfied" it has all the documents necessary to complete its work, a spokesman said yesterday.

Although some informal engineers' notes on Challenger were apparently discarded, this does not appear to have been an attempt to thwart the panel's investigation, commission and National Aeronautics and Space Administration officials said. Copies of the notes were kept or information in them was also contained in official files that were turned over to the panel, they said.

"Because we believe copies of the documents were kept, the commission is of the opinion it has received the documents necessary to do its job," said commission spokesman Mark Weinberg.

The commission's statement apparently ends a brief controversy that erupted late last week when the panel said it was checking an anonymous, handwritten letter it had received alleging that officials at the Marshall Space Flight Center in Huntsville, Ala., destroyed documents relating to problems in the shuttle's solid rocket boosters. An FBI agent assigned to the commission was dispatched to Huntsville on Friday and NASA Inspector General William D. Colvin also began a probe.

The charge was considered particularly serious because NASA had issued a strict order impounding all documents relating to Challenger immediately after the Jan. 28 accident. The letter -- and a similar one sent to The Washington Post -- contained several specific references to NASA internal codes, leading one agency official to conclude that it was the work of "an insider."

The documents in question were "weekly notes" kept by Marshall engineers and routinely discarded. Agency officials said they were not considered "official files."

Colvin said yesterday he would not comment on his investigation until he had a chance to review the transcripts of interviews conducted at Marshall by the commission's FBI investigator. But a source close to Colvin confirmed that "it doesn't appear as serious as the allegations initially led us to believe."

In a separate development, two Democratic senators, concerned about what aides called a "lack of direction" in Reagan administration space policy, are planning to introduce legislation to overhaul the government's space policy-making apparatus by reviving the old National Aeronautics and Space Council with a full-time staff.

Senate aides said the measure, to be introduced by Sens. Donald W. Riegle Jr. (D-Mich.) and Ernest F. Hollings (D-S.C.), is in part driven by increasing congressional frustration with the apparent inability of the administration's Senior Interagency Group (SIG) on Space to hammer out a consensus on key issues, such as replacing the destroyed Challenger shuttle. A SIG recommendation that the administration proceed with a new orbiter was sent back for more work last week after White House chief of staff Donald T. Regan raised pointed questions about the group's justification for the proposal.

Riegle and Hollings want to replace the SIG -- under the National Security Council and chaired by national security affairs adviser John M. Poindexter -- with the space council to raise the profile of space issues inside the government. The new Cabinet-level council, similar to the one that governed federal space policy from 1958 to 1973, would be chaired by the vice president and report directly to the president.

"This is a direct comment on what people around here think of the SIG," said one Senate staffer.