"In the next few days we are expecting two female 'cosmonauts' to give birth to the world's first offspring conceived in microgravity," Dmitry Atyakshin said.
He said the two expectant mothers are being kept in a separate tank under constant expert monitoring. All space cockroaches feel well, but their behavior and physical condition has changed dramatically.
"The research has just begun, but we can say for sure that, despite the stamina of the cockroaches, weightlessness exerted a serious influence on them, especially on their motor functions - they move slower and get tired quicker," the scientist said, adding that the insects recuperated from the spaceflight amazingly quickly.
More in depth conclusions will be reached after weeks of research.
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 September 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.