Link to sources of information to meet your specific needs:

Library of Congress - search for legislation by subject matter or by bill number
House of Representatives
Senate
White House
White House Office of Science and Technology Policy
NASA (General)
Federal Aviation Administration
Department of Defense
Department of Homeland Security
National Institutes of Standards and Technology
National Science Foundation
Joint Planning and Development Office

Current legislation pertaining to specific subjects can also be located through Congressional committees set up to deal with those certain areas of legislation. Below is a list of key committees dealing with aerospace issues:

House of Representatives

Science Committee
Armed Services Committee
Transportation and Infrastructure Committee
Appropriations Committee

Senate

Commerce, Science and Transportation Committee
Armed Services Committee
Appropriations Committee

Other Useful Information:

U.S. Capitol Switchboard: 202/224-3121
Senate/House Bill Status: 202/225-1772
Senate Document Room: 202/224-7860
House Document Room: 202/225-3456