Russian controllers say they've lost control of a satellite carrying several experiments featuring live geckos -- and their sex lives -- mushrooms and fruit flies, and warn it could plummet back to earth.
The geckos -- four females and one male -- are among the animals and plants on the Foton-M4 satellite, the engine of which is no longer responding to control inputs, officials at Russia's Progress space center said.
All of the other systems on the satellite are still working, allowing researchers to document the experiments, including the geckos, they said.
They were sent into space to see how weightlessness might affect their sex lives and their development, researchers said.
Video cameras have been monitoring the geckos in an experiment designed to "study of the effect of microgravity on sexual behavior, the body of adult animals and embryonic development," the website of Russia's Institute of Medico-Biological Problems says.
"The equipment which is working in automatic mode, and in particular the experiment with the geckos, is working according to the program," said Oleg Voloshin, a spokesman for the institute.
The Russian scientists had hoped to recover the satellite and its living inhabitants at the end of the planned 60-day experiments, but following its July 19 launch its engine failed to respond to ground signals to fire and lift the satellite into a higher orbit.
The firm that built the Foton-M satellite says its experts are working to reestablish control of it.
If those efforts are unsuccessful the geckoes will eventually consume all of their food, and after some months -- perhaps four -- the satellite and all of its onboard experiments will crash back to earth, Russian officials said.
Similar Russian missions with live payloads have had problems previously; in 2013 a Bion-M satellite meant to take mice, gerbils and fish into orbit crashed a short time after its launch, killing the creatures on board.
The Foton-M24 has been described as a "twin" of the Bion-M, although the exact nature of their research missions were said to be different.
An unidentified official of Roscosmos, the Russian federal space agency, said that although the Foton-M24 might still be recovered, "carrying out the program of scientific experiments that had been planned is already at risk."
In addition to the biological experiments, the satellite carries a special furnace designed to analyze the melting point of metal alloys in zero gravity to develop new techniques for the production of semiconductors and nanobiosensors, Roscosmos said.
