MOSCOW, January 6 (Itar-Tass) —— Up to 200 kilograms of fragments of the 5-billion-ruble Phobos-Grunt interplanetary research rover might fall over the Earth from January 10 through 21. The most probable date is January 15, the Federal Space Agency reported on Friday.
It has been monitoring the rover, which failed to set off towards Mars on November 9, 2011, and stayed in a circumterrestrial orbit.
“The dynamics of the rover’s braking in the Earth atmosphere depends on a variety of space and technical factors, including those beyond human control. The main factor is the atmospheric conditions that fluctuate under the influence of the Sun,” the Agency said.
“Judging by the available data and preliminary estimates of the task force controlling the Phobos-Grunt descent from the orbit, the projected fall window is set from January 10 to 21, with the most probable date January 15. The presumed area where Phobos-Grunt fragments may fall over lies between 51.4 degrees South and 51.4 degrees North. The precise spot, date and time of the fragments’ fall may be predicted no earlier than one day ahead,” the Agency said.
From 20 to 30 rover fragments made of heat proof materials with the total weight less than 200 kilograms may hit the ground. Fuel will burn out in dense layers of the atmosphere, at the altitude of about 100 kilometers.
The rover’s total weight is 13,505 kilograms, including 7,150 kilograms of highly toxic fuel in the booster, 1,050 kilograms of fuel in the flight module and 135 kilograms of fuel in the landing capsule. The rover carries a spectrometer with two gamma emission sources using cobalt 57. Space Research Institute Director Lev Zelyony said the sources were not dangerous due to their tiny size.
Specialists say the weight of cobalt 57 does not exceed ten micrograms, besides the substance has a short semi-decay period and will not cause the danger of radioactive contamination.
“Judging by the world’s statistics, spacecraft that go off the orbit usually burn completely in dense layers of the atmosphere and fragments that reach the ground do not make any harm,” the Agency said.
The rover was lifted off Baikonur with a Zenit-2SB rocket at 00:16 a.m. on November 9, 2011. It was put to a low orbit from where the rover was supposed to fly to Mars. For a still unclear reason the engine did not turn on.
The Phobos Grunt launch has been delayed repeatedly since 2009. The vehicle was supposed to reach Mars and spend several months in orbit to choose the best place for landing on Phobos. A landing capsule was due to separate and to reach the moon surface for collecting relic substance, which, in the opinion of scientists, might have formed planets of the solar system. The samples were to be taken to the Earth.
An automatic station was supposed to stay on Phobos to continue the study and to monitor the local climate and circumplanetary space. The station was due to test prospective technologies of Martian flights.
Also, Phobos Grunt was supposed to bring a Chinese micro-satellite to the Martian orbit and joint experiments will be held. The Chinese satellite Yinghuo-1 (or Firefly Light-1) was planned to be placed on Martian orbit within the framework of the joint Russian-Chinese Mars exploration agreement signed in 2007.
In all, Phobos Grunt is carrying over 20 research instruments.
The Soviet Union began its Martian program in October 1960. There were two launches in 1960 and three more in 1962. Four launches were abortive, and only Mars 1 went to space on November 1, 1962. However, contact with it was lost.
Two automatic interplanetary stations, Mars 2 and Mars 3, were launched in May 1971. Mars 2 delivered a capsule with the Soviet state emblem to Mars. The landing vehicle of Mars 3 touched down on December 2. Nevertheless, no information was collected. Four Mars vehicles came to the Martian orbit in 1974, and Mars 6 landed in the Mars southern hemisphere.
Two Phobos rovers were launched in July 1988 for studying Mars and its moon. The first one was lost on the way to Mars and the other reached the Martian orbit. In two months of its work Phobos 2 transmitted information about temperature fluctuations on the Martian surface and 38 images of Phobos.
The latest Martian mission in November 1996 failed. Mars 96 could not reach the designated orbit and was lost. It was an international project.
In all, 20 domestic rovers were sent to Mars since October 1960 and twelve of the missions flopped.