Arianespace can add another mission to their long history of commercial success. Their Vega rocket delivered yesterday, at early morning hours, two satellites to orbit.
VV07 flight was seventh in the history of Vega light launch vehicle and also seventh success. Mission planned for September 16, 2016, assumed to place five satellites on SSO polar orbit: PeruSat-1 on 500 km orbit with inclination at 97.4 and four SkySats on altitude of 675 km with orbital inclination at 98.2. Spacecrafts were remaining under payload fairing with diameter at 2.6 m with length of 7.8 m (with weight of 400 kg) installed on special adapter called VESPA (Vega Secondary Payload Adaptor). On its upper section Arianespace installed SkySat-4, -5, -6 and -7, which were planned to be deployed earlier, on altitude of 500 km. PeruSat-1 was installed in the bottom of VESPA dispenser to be deployed 60 minutes after SkySats on 675 km orbit.
After switching satellites to onboard power systems about 30 minutes before T=0 and testing all systems of the rocket final countdown begun as it was planned. Rocket was launched punctually at 01:43 GMT. Vega, long for 29.9 m (with diameter at 3.025 m) and mass at 137 t started to rise fast over ELA-1 at Guiana Space Center. At T+1′ rocket reached altitude of 16 km with speed at 2700 km/h. At T+2′ first stage of the Vega was cut off and separated correctly on altitude of 56 km. P80 first stage is solid fueled construction with engine providing thrust at 2261 kN. It is long for 11.7 m and burns 88 t of HTPB. Second stage ignited few seconds later and rocket achieved speed of 9700 km/h at T+2’36”. Zefiro-23 second stage started to burn 26 t of HTPB to provide 871 kN of thrust. Zefiro is shorter and more narrow than P80, with length of 8.39 m and diameter of 1.9 m it weighs only 2850 kg. Rocket still was flying with speed of 14000 km/h towards the North Pole and conducted cut off of the second stage at T+3’42” on altitude of 126 km. Third stage, Zefiro-9 ignited its solid fueled motor providing 260 kN of thrust and burning 9 t of HTPB. Zefiro-9 is long for 4.12 m with same diameter as Zefiro-23 (1.9 m) and weighs 1315 kg. At T+4’05” payload fairing was jettisoned after small pyrotechnical charges exploded and split it into two halfs on altitude of 140 km. During that time Vega was still tracked by Galliot station in Guiana remaining 1329 km from launch pad. At T+6’48” AVUM (Attitude Vernier Upper Module) upper stage separated from Zefiro-9 and ignited its single RD-843 engine fueled with 550 kg of UDMH/N2O4. It started to operate and providing thrust on 2.42 kN at T+8′. This featherweight construction, with dry mass of 147 kg and length of 1.7 m (with diameter at 1.9 m), was designed to perform four burns before planned deployment of PeruSat-1. First burn finished at T+14’14”; AVUM reached speed of 28000 km/h and altitude of 325 km. At T+38’08” second burn started on altitude of 505 km. Burn ended at T+39’41” and four SkySat satellites were deployed in two pairs at T+40’27” and at T+40’29” on altitude of 505 km. Next phase of flight was reached at T+44’48”, when VESPA cover was jettisoned to open section where PeruSat-1 was installed. AVUM and PeruSat-1 few minutes later started to be tracked by station located on Bermuda. Finally, third burn of AVUM lasting one minute started at T+1h 41″ and helped in reaching orbit with altitude of 675 km. Two minutes later PeruSat-1 was deployed from cylindrical VESPA container.
Perusat-1 is imaging reconnaissance and monitoring satellite built by Airbus Defense and Space under contract with Peru Government from 2014. Satellite is based on reliable AstroBus-S platform with weight at 450 kg and was equipped with 1-meter panchromatic imager and 2-meter imager operating in 4 spectral bands with operational life at 10 years. Equipment will be powered by onboard batteries and two deployable solar arrays. Satellite will provide high resolution imaging for Peruvian military forces and government agencies especially for monitoring state boarders, climate monitoring, cartography, disaster relief and agriculture planning. It is most advanced imaging satellite (with resolution up to 0.7 m) in Latin America and is result of the cooperation between France and Peru; it was built in less than 24 months along with ground control center in Peru. Additional payload during this mission will be four SkySat imaging satellites built by SSL and operated by Skybox. Each from four satellites weighs 100 kg, is powered by onboard batteries and solar cells and will remain operational for at least six years.