A Russian ground team has made contact with a gecko-carrying scientific research satellite, restoring communications with the spacecraft after officials were unable to control it for a week, the Russian space agency announced Saturday.

Artist's concept of the Foton M4 spacecraft. Credit: TsSKB Progress
 
The Foton M4 satellite houses five geckos, along with various insects, plant seeds and materials research samples, inside a spherical landing capsule, which is supposed to come back to Earth in September with a parachute-assisted touchdown in southern Russia.

Scientists sent up the geckos to keep track of their sexual habits during the two-month mission, research that officials say could yield information on how reproductive behavior might be altered during long-duration space missions.

The space capsule launched July 18, but the spacecraft stopped responding to commands from ground controllers a few hours after liftoff. The capsule missed a planned rocket burn to raise its orbit to the planned 575-kilometer (357-mile) altitude.

As of Saturday, orbit data supplied by U.S. Air Force surveillance radars showed the Foton spacecraft still had not raised its orbit, which has a low point about 250 kilometers (155 miles) above Earth.

Without maneuvering to raise its altitude, it is not clear how long the Foton M4 capsule can remain in an orbit where drag from the Earth's upper atmosphere is strong enough to make objects fall back to the planet and burn up.

The landing module, based on the Vostok capsule flown by Yuri Gagarin on the first human spaceflight in 1961, is fitted with a heat shield and is designed to survive re-entry.

The pressurized section of the Russian-made spacecraft contains the gecko habitat to supply the animals with food and air to breathe.

Scientists wanted to monitor the sexual behavior and embryonic development of the five adult geckos, according to Russian Federal Space Agency, or Roscosmos. Scientists expected to have a continuous video recording of the gecko habitat aboard the spacecraft.

A photo of the Foton spacecraft's gecko habitat before launch. Credit: Roscosmos
 
Scientists planned to study dried seeds and silkworm eggs inside the Foton space capsule to determine their response to cosmic radiation, and the satellite carries several experiments for research into microbes.

The mission is the 16th flight of a recoverable Foton spacecraft since 1985.

Engineers introduced several upgrades on the Foton M4 mission to extend the duration of the flight, including solar panels to generate electricity and a new propulsion module to adjust its orbit.

According to information posted on the Roscosmos website, the Foton M4 spacecraft is packed with nearly 1,900 pounds of research hardware inside and outside the capsule.

A joint Russian-German experiment inside the capsule is designed to measure the growth of semiconductor crystals in microgravity, an investigation scientists hope will lead to advancements in solar cells, light emitting diodes, transistors and other applications in the electronics industry.

"The goal is to produce crystals with the highest possible quality," said a statement by DLR, the German space agency.

Three types of materials were to be heated up inside a Russian-made furnace housed inside the Foton M4 spacecraft. Once melted, the samples will crystallize as scientists study the influence of magnetic fields and vibrations on their growth.

Preflight plans called for the samples be divided among Russian and German scientists at the end of the mission.

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