The records include: 1) Preliminary Control Series of reports, photographs, and other materials submitted to the Commission by NASA and its contractors to provide background information on technical aspects of the Space Shuttle program; also includes some of the Commission's correspondence and internal memorandum (records preserved in paper, microfilm, and some as electronic dataset); 2) Transcripts of the Commission's various panels which investigated a variety of technical issues; of hearings held by the full Commission; and of interviews conducted by Commission staff members with employees of NASA and its contractors (exist in both paper and electronic format with a few exceptions); 3) Correspondence of the Commission Series comprising correspondence of the Commission, primarily letters received from the public, and some from journalists and members of Congress (preserved in their original paper format); 4) Affidavits: the electronic records include a dataset with the text of three affidavits taken by the Commission; the paper records do not contain an affidavits file, making it difficult to determine the relationship between the electronic file and the affidavits in the paper records; 5) Videotapes of the launch, press conferences, Commission meetings, and other events (available through Motion Picture, Sound, and Video Branch); 6) Sound recordings of a majority of the interviews and hearings conducted by the Commission (available through motion picture, Sound, and Video branch.