"To chart the course by pioneering new-technologies, methodologies and scientific-discoveries."
NASA's charter includes making huge and often unprofitable investments in treasure and unfortunately, sometimes in lives, necessary to the pursuit and acquisition of knowledge. Knowledge that benefits the United-States and through her, all of humanity.
Every air-vehicle flying in the world today has some NASA legacy. With developing-nations on the rise, NASA's aeronautical work must be further challenged for the United-States to keep it's leadership in aviation.
NASA has pioneered and established the fundamental-technologies and methodologies of travel to LEO. Phasing it to the private sector with it's CCP and CCiCap programs and actively encouraging the growth of that sector at this point is the right thing to do.
NASA's current space-exploration plans are results of a tumultuous-past and an uncertain-future. NASA's stated mission of exploring Mars or visiting a NEO is too narrow. Both Mars and NEOs should be missions within the scope of a imagination-capturing "Grand Mission" such as "Exploring the entire Solar-System within the next 30 years!"... Projects to probe the Jovian and Saturnian moons are well-developed. With commiserating funding NASA should initiate those and develop and execute plans for sending up-to-date missions to the rest of the Solar-System. Reinforcing a continuing-message that the United States are in deeds the drivers for advancement into tomorrow. Think big!. Set lofty goals!. NASA is the only 'space-exploring-organization' on Earth with the 'street-creds' to 'walk-their-talk'. Take advantage of this.
Further leverage NASA in education and especially as a 'driver-for-ambition'. Encourage the publication of NASA-derived lessons-and-imagery in textbooks. Establish and promote NASA branding.
Shape NASA as an enhanced diplomatic tool. The offer of a scientific-partnership might add fresh-air to an otherwise stale situation. Where possible, morph new challenges into space-races.