asteroids and comets. (b) Implementation Consistent with section 71103 of this title, the Director of the Office of Science and Technology Policy shall implement, before September 30, 2012, a policy for notifying Federal agencies and relevant emergency response institutions of an impending near-Earth object threat if near-term public safety is at risk, and assign a Federal agency or agencies to be responsible for protecting the United States and working with the international community on such threats. . (2) Chapter heading typeface The chapter heading of chapter 715 of title 51, United States Code, as added by paragraph (1), is amended so that the typeface of that chapter heading conforms to the typeface of other chapter headings in title 51, United States Code. (3) Chapter table of contents typeface The chapter table of contents of chapter 715 of title 51, United States Code, as added by paragraph (1), is amended so that the typeface of the subchapter headings and the typeface of the subchapter items conform to those appearing in other chapter table of contents of title 51. (4) Subchapter heading typeface The subchapter headings for subchapters I through IV of chapter 715 of title 51, United States Code, as added by paragraph (1), are amended so that the typeface of those subchapter headings conforms to the typeface of subchapter headings in other chapters of title 51, United States Code. (z) Enactment of Chapter 717 Title 51, United States Code, is amended as follows: (1) Content Title 51, United States Code, as amended by subsection (y), is amended by adding after chapter 715 the following: 717 ADVANCING HUMAN SPACE EXPLORATION SUBCHAPTER I—GENERAL PROVISIONS Sec. 71701. Definitions. SUBCHAPTER II—ADVANCING HUMAN DEEP SPACE EXPLORATION Part A—Assuring Core Capabilities for Exploration 71711. Space launch system, Orion, and exploration ground systems. Part B—Journey to Mars 71721. Human exploration roadmap. SUBCHAPTER III—ADVANCING SPACE SCIENCE 71731. Policy on maintaining balanced space science portfolio.