This episode takes place in July 1976, January 1999, April 2000 and June 2001.
One of the core "suspension of disbelief" factors in the series is that Mars is shown with a breathable oxygen atmosphere (albeit described as "thinner than that of Earth") as well as canals containing liquid water. This plot device allows the characters to move around Mars freely without the use of space suits, thus negating the need for expensive props and special effects.
Actors Phil Brown (the narrator) and Burnell Tucker (Bill Wilder, the Captain's brother) were both in the original Star Wars.
The method in which spacecraft travel to Mars were all real programs of NASA but were originally designed for transit to the Moon. The small craft flown by Captain York, which launches to connect up to a massive rocket in Earth orbit, was known as the "Earth Orbit Rendezvous" or EOR program and was the most heavily favored method of moon transit by NASA engineers. The larger rockets seen in the later expeditions were based on the "Direct Ascent Program", which several engineers wanted to reach the moon, but which Wernher von Braun was against due to the size required for the rocket. The last method, which was actually used to reach the Moon, involved assembling landing craft in space and the using a small landing vehicle to reach the moon's surface, and was known as "Lunar Orbit Rendezvous", of which no equivalent is seen in the Martian Chronicles.
On "Ray Bradbury Theater" several years later, David Carradine would play Spender, which is Bernie Casey's role here. Both actors starred in Martin Scorsese's "Boxcar Bertha" in 1972.