To arrange key events in the exploration of space in the correct chronological order, we can reference the following events:
- First humans in space: Yuri Gagarin's flight on April 12, 1961.
- First humans on the moon: Apollo 11 mission with Neil Armstrong and Buzz Aldrin on July 20, 1969.
- First space shuttle flight: STS-1 in April 1981.
- Hubble Space Telescope launch: April 24, 1990.
- First lander on Mars: Viking 1, which landed on Mars on July 20, 1976.
- Last humans on the moon: Apollo 17, the last crewed mission to the moon, landed on December 11, 1972.
- Launching of the International Space Station: First module, Zarya, launched on November 20, 1998.
- First humans on Mars: This event has not occurred yet as of my knowledge cut-off in October 2023.
With this chronology, the correct order of events from the list options provided would be:
First humans in space, first humans on the moon, first space shuttle flight.
None of the other lists provided fit perfectly, but the series of events involving humans in space and the moon and shuttle flight is accurate.