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 space shuttle Challenger was one of NASA's greatest triumphs. It was the second shuttle to reach space, in April 1983. It successfully completed nine milestone missions. But Challenger was also NASA's darkest tragedy.On its 10th launch, on Jan. 28, 1986, the shuttle exploded 73 seconds after liftoff, killing the seven crewmembers. The accident changed the space program forever.ut Challenger was also NASA's darkest tragedy. On its 10th launch, on Jan. 28, 1986, the shuttle exploded 73 seconds after liftoff, killing the seven crewmembers. The accident changed the space program forever.