Children react as a tiny Mars Rover rolls over their backs at the USA Science and Engineering Festival, Saturday, Oct. 23, 2010, at Freedom Plaza in Washington. NASA, joined with more than 500 science organizations this weekend to inspire the next generation of scientists and engineers during the first national science and engineering festival held in the nation's capital. Photo Credit: (NASA/Paul E. Alers)

Priniciples of air flow are explained to visitors to the wind tunnel exhibit at the USA Science and Engineering Festival, Saturday, Oct. 23, 2010, at Freedom Plaza in Washington. NASA, joined with more than 500 science organizations this weekend to inspire the next generation of scientists and engineers during the first national science and engineering festival held in the nation's capital. Photo Credit: (NASA/Paul E. Alers)

Visitors crowd the NASA exhibits during the USA Science and Engineering Festival, Saturday, Oct. 23, 2010, on the National Mall in Washington. NASA, joined with more than 500 science organizations this weekend to inspire the next generation of scientists and engineers during the first national science and engineering festival held in the nation's capital. Photo Credit: (NASA/Paul E. Alers)

A young girl watches as her paper airplane is flown in a small wind tunnel during the USA Science and Engineering Festival, Saturday, Oct. 23, 2010, at Freedom Plaza in Washington. NASA, joined with more than 500 science organizations this weekend to inspire the next generation of scientists and engineers during the first national science and engineering festival held in the nation's capital. Photo Credit: (NASA/Paul E. Alers)

Participants look through telescopes to observe the Sun during the USA Science and Engineering Festival, Saturday, Oct. 23, 2010, at Freedom Plaza in Washington. NASA, joined with more than 500 science organizations this weekend to inspire the next generation of scientists and engineers during the first national science and engineering festival held in the nation's capital. Photo Credit: (NASA/Paul E. Alers)

Visitors to the USA Science and Engineering Festival look over the many exhibits, Saturday, Oct. 23, 2010, at Freedom Plaza in Washington. NASA, joined with more than 500 science organizations this weekend to inspire the next generation of scientists and engineers during the first national science and engineering festival held in the nation's capital. Photo Credit: (NASA/Paul E. Alers)