Italian job – Vega delivered Turkish military satellite to orbit

Less famous comparing to Ariane opr Soyuz, but still reliable and useful for certain kind of missions; today's launch of Vega rocket showed, that Italian space industry still has something to say.

It was 8th mission with manufactured by Italian Avio Vega rocket and second launch of this Italian rocket operated by Arianespace in 2016. With 100% success ratio, Vega showed again, that Italian Space Agency has capabilities to design own launch vehicles on very high level. Twelve years of development, since 1998 when Vega program started until first mission in 2012, have not been wasted. Rocket is reliable and proven launch vehicle and surely can be strong point in Arianespace portfolio, specially for customers who are looking for launch vehicles suitable for payloads under 2500 kg (lowest payload mass for Vega is 300 kg).

VV08 mission could be shortened to two numbers: 1060/700. Gokturk-1, representing latest technology in Earth imaging weighs 1060 kg and has designated orbit of 700 km. Preparing for launch started after arrival of Gokturk-1 to Guiana on October 24. After unpacking and test of satellite, procedure of  installing Gokturk-1 on atop of standing inside assembling facility Vega rocket  started on November 28. Since then, engineers and technicians tested rocket and satellite to give final go for starting countdown procedure. It started exactly nine hours before launch planned for 13:51 UTC. At T-5h50' Multi-Functional Unit was activated, what was followed by activation of Inertial Reference System and Telemetry System twenty minutes later. Safeguard Master Unit was activated at 08:51 UTC and after removing safety devices twenty minutes later, main onboard computer of the rocket was turned on. Technicians loaded flight program and performed Inertial Reference System tests and calibration. They were repeated after retracting mobile gantry along with turning on transmitter for Telemetry System and all sensors and communication devices at T-1h15'. Thirty minutes before launch rocket was already switched to onboard power and after last weather forecast confirmation ten minutes before T=0, everything was ready for flight.

Finally at 13:51 UTC rocket started from ELA-1 launch pad and perform its normal maneuver to face towards East. At T+40' rocket already reached speed of 1 Ma and was getting close to point of maximal dynamic pressure planned to be passed on altitude of 15240 m at T+1'. One minute later, first stage was cut off and separated. In this moment it is worth to give some details on P80FW first stage. It is one of the largest solid fueled rocket stages in the world. It is long for 11.7 m with diameter of 3 m and mass of 95695 kg. It burns 88 t of HTPB generating thrust of 2261 kN. After separation of P80FW, Zefiro-23 second stage was ignited. It started to burn 26 t of HTPB to provide 871 kN of thrust. Zefiro is shorter than P80FW; it is long for 8.39 m with diameter of 1.9 m,  it weighs only 2850 kg. It burned for next 115 seconds until T+3'55" when it was cut off. It separated correctly and Zefiro-9A third stage, started to work. It is also solid fueled (HTPB) and is burning 9t of propellant providing 260 kN of thrust. It is long for 4.12 m with same diameter as Zefiro-23 and dry mass of 1315 kg. When rocket was still flying toward East, fifteen seconds later payload fairing was jettisoned. At T+19' Zefiro-9A was cut off and it separated; AVUM upper stage ignited one minute later of 6'19". AVUM (Attitude Vernier Upper Module) is powered with single Russian RD-843 engine burning N2O4/UDMH propellant and providing 2.42 kN of thrust. With mass of 147 kg and length of 1.7 m (with 1.9 m of diameter) it is restartable construction. Next burn was planned for 14:45 UTC; it was necessary to circularize orbit to 700 km (with inclination at 98.11°), with impulse lasting for 102". At 15:47 UTC second burn was finished and five minutes later Gokturk-1 was separated. First report from satellite was received on Earth at around 15:10 UTC - satellite deployed solar arrays and is communicating correctly.

Gokturk-1 is high resolution (up to 0.8 m) imaging satellite ordered by Turkish Ministry of Defense. Contract was signed in 2009 with Telespazio, Italian company, and it was valued for at least  € 250 million. Telespazio was chosen not only for designing, manufacturing but also as contractor for launch service. Company is also responsible for providing ground facilities and technology necessary for operating satellite by military. Secondary contractor was Thales Alenia Space – its contribution into Gokturk-1 project will be Proteus satellite bus. Satellite is three axis stabilized and is able to spent 7 years on 700 km orbit. Mass of the satellite is 1060 kg with dimensions of 4.2 m x 2.5 m x 1.6 m.