Five geckos sent into orbit on a Russian space satellite as part of a breeding experiment have all died, the Russian space agency reports.
Sent aboard the Russian Foton M-4 satellite, these poor geckos - four females and one male - met their demise just one week before returning to Earth on Monday. They were sent into space as part of a study into the effect of weightlessness on breeding and development.
"We can't say yet at which stage of Foton's space flight it happened," the RIA Novosti news agency quoted a source at the Russian Academy of Sciences as saying.
There will be an investigation into the cause of death of these reptilian cosmonauts, but experts say the geckos may have frozen to death after the heating system broke down, Russian news agencies report.
"We can say with confidence that they died at least a week before the landing because their bodies were partly mummified," an official from Russia's Institute of Medical and Biological Problems told ITARR-TASS News Agency.
"Hypothermia is not the main possible cause but only one of the options. Others include a possible malfunction of the onboard equipment and life-support system," the source added.
However, perhaps the silver lining in all this is that the Drosophila fruit flies that accompanied the geckos on their space sex mission are still alive. In fact, the flies successfully grew and bred in space.
Despite this small victory, the mission had its fair share of troubles. Foton-M4 stopped responding to commands shortly after its July 19 launch, and although full contact was restored, the satellite was left in an orbit that was more elliptical than intended. More communication problems emerged last week, forcing the satellite to return earlier than planned.
The six-ton satellite was meant to carry out experiments over a two-month period, but returned after just 44 days in orbit.
Aside from the geckos, other specimens on board included silkworm eggs, dried seeds and mushrooms that were also being monitored as part of the experiment.