Kosmos 31 was placed into a low Earth orbit with a perigee of 221 kilometres (137 mi), an apogee of 485 kilometres (301 mi), 48.9 degrees of inclination, and an orbital period of 91.7 minutes. It decayed from orbit on 20 October 1964. Kosmos 31 was the second of three DS-MT satellites to be launched. The first was lost in a launch failure in June 1963, and the third was Kosmos 51, which was launched in December 1964.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Manned flights are indicated in bold text. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in brackets.