(a) Fiscal years ending June 30, 1976, and September 30, 1977, through September 30, 1980
For the fiscal years ending June 30, 1976, and September 30, 1977, 1978, 1979, and 1980, only such sums may be appropriated as the Congress may hereafter authorize by law.

(b) Fiscal year ending June 30, 1975
There are authorized to be appropriated to the National Aeronautics and Space Administration not to exceed $2,500,000 for the fiscal year ending June 30, 1975, for the purpose of preparing the program definition under section 1122(a) of this title.

(c) Additional sums for Project
In addition to sums authorized to be appropriated by subsection (b), there are authorized to be appropriated to the fund not to exceed $50,000,000 annually, such sums to carry out the provisions of the loan guaranty program by the Project under subchapter II.