Suited to endure long periods of inactivity

Say what you will about the Sovi­ets, but you can't argue with this rea­son­ing for send­ing dogs, rather than mon­keys, into space. If there's one uni­ver­sal truth of dogs, it is that they are "suit­ed to endure long peri­ods of inac­tiv­i­ty." Lynne brought the sub­ject of these Sovi­et cos­mo­naut dog-heroes to my atten­tion, includ­ing those pic­tured at right — Bel­ka (which "most like­ly means 'Whitey,'" accord­ing to Wikipedia's "Sovi­et space dogs" entry) and Strel­ka ("Arrow"). They were the first ani­mals to go into orbit and return alive, spend­ing August 19, 1960 in space before return­ing to Earth. Wikipedia help­ful­ly adds that they were accom­pa­nied by some friends from the ani­mal king­dom: "a grey rab­bit, 42 mice, 2 rats, flies and a num­ber of plants and fun­gi." All pas­sen­gers sur­vived.(Thanks to Dan Mog­ford, who grabbed the image off a com­mem­o­ra­tive Sovi­et matchbox).