MOSCOW, January 4 (Itar-Tass) — Fragments of the Phobos-Grunt probe not burnt in the atmosphere are expected to fall onto the earth on January 15, the Russian Air and Space Defence Troops' spokesman Alexei Zolotukhin told Itar-Tass.
The date of the fall may change depending on some factors, he added.
Specialists of the main centre of the troops' space situation reconnaissance are monitoring the changes of the orbit.
As of January 4, 2012, the object is in an orbit with the period of 88.57 minutes, the inclination of 51.41 degrees, the apogee of 224 km and the perigee of 184 km.
The centre regularly receives full and reliable information from special radio technical, optronic and laser sensors of the Russian space control system. When the spacecraft comes off the orbit, the analysis of the information will allow preliminarily forecasting when and where its fragments will fall.
Specialists of the control centre monitor the circuits and analyze the state of the Phobos-Grunt. Information about the orbit changes is provided for all the parties concerned, the official said.
The Phobos-Grunt probe was launched from Baikonur on November 9, 2011. The probe was expected to take a soil sample from Mars's moon Phobos and deliver it to Earth. The interplanetary spacecraft came to a low orbit around Earth, from where with two startings of the propulsion system it was to leave the orbit for the further mission course. For reasons unknown yet, the control system failed to give the command for the first propulsion starting. An interdepartmental commission was formed to investigate the causes of the failure. The commission is expected to present its preliminary conclusion in late January.