Several weeks back, we learned of the harrowing tale of the zero-g sex geckos: blasted into low Earth orbit aboard the Russian Foton-M4 satellite as part of a biological experiment to study reproduction in microgravity, the sex geckos mission was endangered almost from the beginning when Russian space agency Roscosmos lost positive control over the geckos’ spacecraft. Roscosmos was able to receive telemetry, but it couldn't send commands. Without ground control, the Foton-M4 would slowly decay out of orbit and enter the atmosphere uncontrolled.

Further Reading Outlook grim for orbiting Russian zero-G sex geckos

Fortunately, Roscosmos was able to reestablish its uplink only a few days later, and the experiments continued. Unfortunately, as is so often the case with pioneers who push forward the boundaries of scientific knowledge, all five of the geckos have died

Their passing was discovered during recovery operations for the Foton-M4 spacecraft, which successfully de-orbited and landed as planned in southern Russia yesterday afternoon. When the intrepid reptiles’ enclosure was examined, it was found to contain five tiny mummified gecko bodies. Preliminary indications are that the geckos all froze to death.

According to a statement (in Russian) from the Russian Institute of Biomedical Problems, the geckos could have died at any stage in the flight; it is as yet unclear why, but it’s likely that there was a malfunction in the temperature-control component of the gecko habitat’s life-support equipment. Further investigation is planned to more accurately determine the time and cause of the geckos’ demise.

The most important question—whether or not the sex geckos were able to join the Million Mile High club before death—remains unanswered. As explained by the Moscow Times, the Foton-M4 craft wasn’t equipped to transmit live video; the geckos’ mating (or lack of mating) was videotaped for study after the landing. Wired says that there was in fact no zero-g sex for the tiny doomed space travelers.

However, even in the face of tragedy, life continues: the geckos’ fellow travelers on the Foton-M4 spacecraft, a habitat full of Drosophila flies, were in fact able to mate in microgravity.