The reason for the emergency launch of Galileo satellites is the Fregat upper stage
On Friday evening, not only the Falcon-9 missile tests ended in a non-calculated manner. On the same day, the Russian carrier Soyuz-ST, launched from the Kourou cosmodrome in French Guiana, put two satellites of the European Galileo navigation system into an off-design orbit.
The cause of the accident was the abnormal operation of the Fregat-MT upper stage, developed at the Lavochkin Scientific Production Association.
The standard Galileo orbit is circular, at an altitude of 23,222 km and with an inclination of 56 degrees, but these two satellites were launched into an elliptical orbit with an apogee of 26,900 km, a perigee of 13,700 km and an inclination of 47 degrees. There is a theoretical probability that the devices can be delivered to the target orbit using their own engines, but this is, firstly, unlikely, and secondly, even if successful, this will greatly reduce the satellite resource due to the impossibility of further orbit correction. Now ESA experts are trying to understand whether something can be done, but most likely this launch will be recognized as completely unsuccessful, and the devices - lost: in spite of the full working capacity of all systems, they cannot work from the orbit on which they ended up.
This launch was the 38th in ten years of operation of the Soyuz-2 family of missiles - and the second failed (the first was in 2011, the cause of the accident was the abnormal operation of the third-stage engine).
A source from the Interfax agency expressed concern that due to the accident, the European Space Agency might consider launching the following Galileo spacecraft using its own Ariane-5 missiles, rather than cheaper Unions. To date, all four operational Galileo navigation systems have been launched by "Unions".
The cause of the accident was the abnormal operation of the Fregat-MT upper stage, developed at the Lavochkin Scientific Production Association.
The standard Galileo orbit is circular, at an altitude of 23,222 km and with an inclination of 56 degrees, but these two satellites were launched into an elliptical orbit with an apogee of 26,900 km, a perigee of 13,700 km and an inclination of 47 degrees. There is a theoretical probability that the devices can be delivered to the target orbit using their own engines, but this is, firstly, unlikely, and secondly, even if successful, this will greatly reduce the satellite resource due to the impossibility of further orbit correction. Now ESA experts are trying to understand whether something can be done, but most likely this launch will be recognized as completely unsuccessful, and the devices - lost: in spite of the full working capacity of all systems, they cannot work from the orbit on which they ended up.
This launch was the 38th in ten years of operation of the Soyuz-2 family of missiles - and the second failed (the first was in 2011, the cause of the accident was the abnormal operation of the third-stage engine).
A source from the Interfax agency expressed concern that due to the accident, the European Space Agency might consider launching the following Galileo spacecraft using its own Ariane-5 missiles, rather than cheaper Unions. To date, all four operational Galileo navigation systems have been launched by "Unions".
')
Source: https://habr.com/ru/post/234399/
All Articles