Note: Dates in bold type are taken from the stories, or from known astronomical data. Dates in italics are estimates based on the information in the stories. Some inconsistencies are discussed on page six.
Circa 13000 BC
Martian civilization is at its height. A Martian expedition visits Earth, and the pre-Dynastic Egyptian culture treats the explorers as gods. One is remembered as Thoth.
Early 20th Century
Experiments with chemical rocketry and nuclear power.
Atomic blast perfected by Doheny.
Cardoza expedition to the Moon.
De Lancey expedition to Venus ends in disaster.
Ares expedition to Mars; further expeditions to Mars and Venus.
A Martian Odyssey, Valley of Dreams
International Congress at Lisle apportions the surface of Venus to the nations that have colonised it.
Moons of Jupiter and Saturn explored and colonized.
First Pluto expedition
Council of Berne decides that explorers cannot claim entire planets or moons, but only the areas actually explored.
First expedition to Uranus.
The Red Peri
Parasite Planet, The Lotus Eaters
Second expedition to Uranus.
Planet of Doubt
False expectations of a gold strike on Venus cause the failure of the Planetary Trading Corporation and a stock market crash. The Gunderson expedition to Europa crash-lands on its return to Earth.
Flight on Titan, The Mad Moon
A Martian Odyssey states that Venus has not yet been colonized. Parasite Planet dates the partition of Venus at 2020. This means that Venus must have been colonised by several nations between the date of the first Mars landing and 2020. Assuming roughly a decade of colonization puts the date of the Ares expedition at circa 2010. The dates for the atomic blast and Moon landing are based on the chronology mentioned in A Martian Odyssey.
Flight on Titan gives much later dates for the first lunar landing and the gold crisis, states that Martian civilization is dead, and gives a different name for the first man to land on the Moon. However, it conforms to the canon of the other stories in most other respects and is generally considered to be part of this sequence. Since the gold crisis is given as 2110 in two other stories these variations have been ignored.
Wikipedia dates The Red Peri at 2083, 150 years after the first flight over Mount Everest (the anniversary is mentioned), but this may be an approximation, not an exact figure; the story is set after a conjunction of Saturn and Pluto, and there was a prior landing on Pluto which must have occurred at a previous conjunction. Conjunctions occurred in 2053, 2085 and 2118; assuming a first landing in 2053, a date circa 2086 seems most likely.
Comments are appreciated.