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Fobos-Grunt rocket 2nd stage debris may fall in India Ocean Nov 22

November 21, 2011, 14:07 UTC+3
The actual time of the fall may differ from the forecast time by up to 24 hours either waу
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MOSCOW, November 21 (Itar-Tass) — The debris of the second stage of the Zenit launch vehicle that on November 9 launched into space the automatic interplanetary station Fobos-Grunt (Phobos-Soil) may enter the Earth atmosphere on November 22 and fall into the Indian Ocean in the area of the Java Island at about 23:15, Moscow time (MSK).

According to specified data of a website subordinate to the US Strategic Command, the actual time of the fall may differ from the forecast time by up to 24 hours either way. According to the website data, which are constantly updated, the forecasted point of fall of the stage is at the coordinates: 11 degrees South latitude, 109 degrees, East longitude.

The launching of the Phobos-Soil station was carried out on November 9 from the Baikonur Cosmodrome by the Zenit-2SB launch vehicle. The station has successfully reached the low Earth orbit, from which it was to be transferred to an interplanetary trajectory from Earth to Mars by means of switching on the main propulsion system. Due to unknown reasons, the control system has failed to give a command to the first ignition of the propulsion system. All attempts to make contact the station have been futile so far.

Head of the Russian Federal Space Agency (Roskosmos) Vladimir Popovkin said earlier that it would be right to say that the Phobos is “dead” in early December, “when the window closes” (for the possible flight of the expedition to Mars). “The Phobos existence end prognosis can be started when due to the orbit degradation its perigee altitude will be less than 180 kilometres,” he added.

According to the agency head, Russia’s Phobos-Grunt interplanetary research probe will stay on the orbit through January. “We have time till January inclusively, the spacecraft will be on the orbit but the window will close in early December,” he said. “There are certain chances but so far we have no telemetry data to get a clear picture of what has happened,” he said. “The problem lies in the fact that it takes time to adjust surveillance stations while the Phobos is running along an abnormal orbit, so a radio contact is only established for a time span of seven minutes.”

“All the systems of the spacecraft are operating in a regular mode, orienting it towards the sun, which means that we still have some chances,” Popovkin noted. “Specialists are currently trying to load programs.” When asked about the date of “death of the spacecraft,” Popovkin said that “one can speak about it on the first days of December, when the window is closed.” “It will be possible to forecast the end of Phobos’ life when the orbit degrades to 180 kilometres,” he stressed. Popovkin refuted reports that the spacecraft allegedly has design defects. “These reports have nothing to do with the real state of things,” he said. According to the head of Roskosmos, Phobos’ possible descend will pose no threat to the Earth. “No doubts that the spacecraft will explode as soon as it reaches dense atmosphere,” he underlined.

Roughly 7.5 metric tons of highly toxic hydrazine and nitrogen tetroxide are on board, according to the head of Roskosmos. It is mostly fuel for the spacecraft’s upper stage. The amount of fuel is nearly 20 times the amount that was on board the American spy satellite USA-193, which was shot down before re-entry by the US in February 2008. These compounds, with melting points of 2 °C and -11.2 °C, are normally kept in liquid form; if the probe is not rescued but they remain liquid, they are expected to burn out during re-entry. NASA veteran James Oberg said the hydrazine and nitrogen teroxide “could freeze before ultimately entering.” If Phobos-Grunt is not salvaged, it may be the most dangerous object to fall from orbit. However, the head of Roskosmos says the probability of parts reaching the Earth is “highly unlikely,” and that spacecraft will be destroyed during re-entry.

Fobos-Grunt is the first Russian interplanetary mission since Mars 96, which suffered a launch failure. The last Russian or Soviet interplanetary mission that was successfully launched was the second probe of the Phobos program in 1988. Fobos-Grunt is the first sample return mission to the natural satellite of another planet conducted by mankind. If successful, Fobos-Grunt could pave way to a number of Russian interplanetary missions, including missions to the moons of Jupiter, Saturn and Uranus, and asteroid and comet sample return missions.

The Russian Federal Space Agency has said 90 percent of Phobos-Grunt is made of new and untested elements. The new instruments are being tested and will be tested during the flight. According to lead scientist Alexander Zakharov, the entire spacecraft and most of the instruments are new, although they do draw on the heritance of the three successful Luna sample-return missions of the 1970s. Zakharov has described the Phobos sample return project as “very difficult,” possibly “the most difficult interplanetary one to date.”

 

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