Probes.

Space research carried out in the second half of the decade while the shuttle was delayed and budgets were cut was done mainly by space probes. Probes, with no need for life support, could go further and endure harsher conditions than spaceflight involving humans. The various probe programs of the 1970s (all with romantic names: Mariner, Voyager, Viking, Pioneer) sent back information about the five nearest planets: Mercury, Venus, Mars, Jupiter, and Saturn. Uranus and Neptune would be reached in the next decade.

Martians.

Some of the earliest and most eagerly awaited photos came from Mars. In the 1960s three of the Mariner probes had successfully flown by Mars and returned with pictures. But NASA hit the jackpot with Mariner 9 in January 1972: unlike previous space probes, this one orbited the planet. After a week of blinding dust storms, Mariner suddenly began...