Russia has lost control of a satellite carrying lizards in space for an experiment on animal sex in zero-gravity.

The satellite containing the gecko lizards, along with a number of insects and plants, has stopped responding to ground control and officials, for the first time since its July 19 launch.

Scientists running the experiment aim to learn about the effect of weightlessness on the sex lives of geckos, and on their lives in general in zero-gravity conditions. Interfax, the Russian news agency, has cited an expert who claims the satellite could remain in orbit for as long as 4 months.

The Foton-M4 satellite contains five female geckos and one male and was originally intended to remain in orbit for 60 days. Those running the mission will have to regain control if the satellite is to land safely.