National Aeronautics and Space Administration Authorization Act, 1991

National Aeronautics and Space Administration Authorization Act, 1991 - Authorizes appropriations to the National Aeronautics and Space Administration (NASA) for: (1) research and development; (2) space flight, control, and data communications; (3) construction of facilities; and (4) research and program management, including scientific consultations; and (5) Inspector General.

Permits appropriations for the first two numbered categories to be used for certain items of a capital nature (other than land acquisition) required for the performance of research and development contracts, and for grants to nonprofit educational and research organizations to augment their research facilities. Prohibits the use of these funds for the construction of any major facility whose estimated cost exceeds a specified amount unless the Administrator of NASA notifies specified congressional leadership and committees.

Authorizes fund use, subject to limitations, for facilities construction, repair, or modification and for unforeseen programmatic facility project needs.

Permits upward variances of funds for facilities construction under circumstances outlined in this Act.

Authorizes certain fund transfers and makes available specified funds for the construction and modification of laboratories and other installations. Requires the Administrator to notify specified congressional leadership and committees of the nature, cost, and need for such construction before expending the funds in question.

Prohibits, until 30 days following congressional receipt of the Administrator's full explanation, the use of funds appropriated pursuant to this Act for any program that: (1) has been eliminated by the Congress; (2) is in excess of the amount actually authorized for the particular program (except for construction of facilities); or (3) has not been presented to either of the relevant congressional committees.