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.
The next shuttle launch was the seventh flight of the Discovery orbiter, which returned to flight on September 29th, 1988. Among other things, the flight delays caused by the Challenger disaster included a delay in the deployment of the Hubble Space Telescope, in addition to a fleet of classified satellites.