Russia's Mission To Film Geckos Having Sex In Space Ended Tragically

A Russian space experiment to investigate how zero gravity affects the sexual behavior of geckos has ended in tragedy.

Five geckos, one male and four female, launched into space in July aboard Russia's Photon-M satellite died on their journey back to Earth, the Russian Space Agency said in statement.

The satellite landed successfully in South Russia on Monday, but the lizard crew didn't make it. Some fruit flies that were also onboard did survive.

The cause of death has not yet been confirmed. According to The Guardian, a source told Interfax that based on "preliminary information, it became clear the geckos froze." The source added: "Most likely, this happened due to a failure of the equipment meant to ensure the temperature of the box with the animals," The Guardian reports.

The Guardian reporteAccording to the preliminary information, it became clear the geckos froze. Most likely, this happened due to a failure of the equipment meant to ensure the temperature of the box with the animals."

This isn't the first mission setback. The agency lost contact with the gecko-carrying satellite in July and scientists feared that reptiles would starve to death before the satellite came back to Earth.