Christina hammock koch[1] (/ kʊk / cook; Born january 29, 1979) is an american engineer and nasa astronaut of the class of 2013. [2][3] she received bachelor of science degrees.

In 1999 she had her breakthrough hit, genie in a bottle. since then she's made millions of fans, sold millions of records, and won many awards, including a grammy for best new female artist. Recognized as an influential figure in music and having received widespread public interest, she is noted for her four- octave vocal range extending into the whistle register, artistic reinventions, and. Christina marΓ­a aguilera (born december 18, 1980) is an american singer, songwriter, record producer, actress and dancer. Aguilera is known for her strong voice, which can reach high notes, and for.