42 U.S. Code § 18313 - Assurance of core capabilities
The Administrator shall proceed with the development of follow-on space transportation systems in a manner that ensures that the national capability to restart and fly Space Shuttle missions can be initiated if required by the Congress, in an Act enacted after October 11, 2010, or by a Presidential determination transmitted to the Congress, before the last Space Shuttle mission authorized by this chapter is completed.
In carrying out the requirement in paragraph (1), the Administrator shall authorize refurbishment of the manufactured external tank of the Space Shuttle, designated as ET–94, and take all actions necessary to enable its readiness for use in the Space Launch System development as a critical skills and capability retention effort or for test purposes, while preserving the ability to use this tank if needed for an ISS contingency if deemed necessary under paragraph (1).
Nothing in subsection (c) shall apply to or affect any capability authorized by any other subchapter of this chapter 
 So in original. Probably should be followed by a period.
2013—Subsecs. (c), (d). Pub. L. 112–273 added subsecs. (c) and (d).
Any other subchapter of this chapter, referred to in subsec. (d), was in the original “any other title of this Act”, meaning any other title of Pub.L. 111–267, Oct. 11, 2010, 124 Stat. 2805. In addition to title II which is classified generally to this subchapter, Pub. L. 111–267 contains titles III to XII which are classified generally to subchapters II to XI, respectively, of this chapter and titles I and XIII, 126 Stat. 2809, 2846, which are not classified to the Code.