Though the newborn creatures already eat and drink, micro-gravity conditions may have had an impact on the natural darkening of their chitinous carapace, a part of a cockroach's exoskeleton.
"Cockroaches are born with a transparent carapace, which gradually turns into brown, and the space cockroaches went darker earlier than usual," the scientist explained, adding that final conclusions could be drawn only after the second female had given birth.
"We are pleased by the very fact that they (the cockroaches) came into being," Atyakshin added.
The first unmanned Foton-type spacecraft was introduced in 1985 by the Soviet Union and was based on the famous Vostok spacecraft, which carried the world's first astronaut Yuri Gagarin into orbit in 1961. Since 1980, a total of 12 Foton spacecraft have been launched.
The Sep 14-26 flight was part of an ongoing experiment into the effects of space flight by the Institute of Biomedical Problems (IBMP). The creatures were sealed in special containers and a video camera filmed them during the flight.