A Russian space freighter sinking down to earth – Le Figaro

The Russian Progress cargo was not dropped at the correct altitude for the Soyuz rocket. But experts are categorical, the danger is minimal.

A Russian space freighter is in loss above our heads. The Progress, which was to supply the International Space Station (ISS) has “begun its fall” and he “totally uncontrollable reactions,” said, on condition of anonymity a Russian official told AFP. A disaster scenario worthy films showing (over two hours) a space object hurtling at full speed on the planet Blue …

In France, experts of the National Centre for Space Studies (CNES) evaluate the situation, as their alter ego of NASA and the Russian space agency Roskosmos. And the news is reassuring. Given the altitude and orbit where the spacecraft was dumped seven tonnes by a Soyuz rocket, “there is no risk that the Progress collides with the space station,” says one very good source in France.

Trying to regain control

Similarly, the probability that the ship crashes on Earth are completely void. Those pieces of Progress – titanium tank, docking clamps … – fall on the ground of the planet (the Earth is covered by oceans 70%), in a populated area and injures a human being are “infinitesimal” that is to say close to zero but “non-zero” says a specialist in space industry.

The fallout on Earth of Russian cargo will also last “for several weeks” period during which, the space agencies (CNES, NASA …) will, within the framework of international cooperation, follow fairly accurately with radar and calculate its trajectory while the Russian agency will attempt to resume Control. Objective? Turning its engines, control the path and halt its descent to direct it towards an uninhabited area, usually in the South Pacific. Spacefaring nations are accustomed to managing this type of return to earth “unmanned” of satellites or other space objects once or twice a year. “We’ll know a few hours before his arrival the pieces fall where cargo” insists the expert interviewed. Indeed, in contact with the Earth’s atmosphere, the ship bearing down 8 kilometers per second will undergo a warm-up phenomenon that will melt and disintegrate. Only some solid parts may not melt completely.

“Soyuz has not done the job”

It also remains to know what really happened. According to data collected from the Russian Space Agency, the problem occurred during the release of the cargo. “Soyuz has not done the job; he did not give the sufficient thrust to cargo that reaches the correct orbit,” says a specialist. Instead of being dropped to 250 km altitude and at a given speed in a circular orbit (at an altitude fixed) Progress has been placed too low (200 km) on a circular orbit or an elliptical orbit ( its altitude of 140-160 km alternates to 300 km altitude). But Progress engines are not powerful enough to allow him to return to the target orbit. They are mainly used, as well as antennas, to drive the ISS approach phase and adjust the position of cargo to the dock accurately.