heptane. n. 1. (Elements & Compounds) an alkane existing in nine isomeric forms, esp the isomer with a straight chain of carbon atoms (n-heptane), which is found in petroleum and used as an anaesthetic. Formula: C7H16. [C19: from hepta- + -ane, so called because it has seven carbon atoms].
technically it's not any of those three... After the Apollo program in the late 1960's ended, the president of the United States, Richard Nixon declared in 1973 that the USA would build the Space Shuttle to continue space exploration in low earth orbit.
[ 97 ] NASA's first four manned spaceflight projects were Mercury, Gemini, Apollo, and Skylab. As the first U.S. manned spaceflight project, Project Mercury-which included two manned suborbital flights and four orbital flights-fostered Project Apollo and fathered Project Gemini.. The second manned spaceflight project initiated was the Apollo manned lunar exploration program.