First from pair of new weather satellites designed and built by Lockheed Martin was delivered yesterday to orbit on atop of Atlas V rocket. Launch was performed from SLC-41 at Cape Canaveral eighteen minutes before midnight.
This could be good sum up of present position of ULA on the market – maybe SpaceX got CRS-1 and CRS-2, but still United Launch Alliance is very reliable partner with legendary Atlas V heavy rocket, necessary for delivering to space heavy satellites with GEO as designated orbit. This time again Atlas V rocket long for 62m and powered by Russian RD-180 engines showed that reliability and performance are expensive, but this confidence is worth every dime. Estimated cost of Atlas V, which is at least $100 million in 541 configuration (what is in fact far beyond prices offered by SpaceX for launch service providers outside the USA) is nothing comparing to value of two GOES-R spacecrafts, which is $1.09 billion. In such case reliability is key and most important argument for choice of business partner.
Launch was planned with Atlas V in 541 configuration, what means that GOES-R satellite was covered with payload fairing with diameter of 5 m. Core stage with length of 32.46 m and with diameter at 3.81 was powered by RD-180 engine (fueled with RP-1/LOX) and able to provide thrust at 3827 kN. It was supported by four SRB boosters solid fueled with HTPB, long for 17 m and with diameter at 1.6 m. Each booster can generate 1688.4 kN of thrust. Last digit “1” is determining number of engines in Centaur upper stage. In this case 12 m long and wide for 3.05 m Centaur was powered with single RL-10A engine (fueled with LH2/LOX) and generating thrust at 99.2 kN.
Launch was originally planned for 22:42 UTC and due the favorable weather it seemed possible to keep the schedule. Rocket was waiting at SLC-41 since reaching launch pad after roll out from Vertical Integration Building on Friday afternoon. On Saturday at 15:52 UTC countdown procedure was started. Unfortunately, in different rocket ULA engineers spotted minor problem and it was necessary to perform additional tests and evaluate if unit planned to be used for GOES-R is also affected with issue. Luckily, bad news were not confirmed and it was possible to resume mission and launch Atlas V just in the end of planned launch window. Punctually at 23:42 UTC, rocket ignited core engine and its four boosters. Just after lift off rocket set its designated course at SE and at T+36″ it passed 1 Ma speed. It reached and passed fluently point of maximum dynamic pressure 13 seconds later. All four boosters separated correctly at T+1’34” and after another two minutes GOES-R was exposed after jettisoning payload fairing. One minute after losing payload fairing at around T+4’20”, RD-180 engine was cut off and separated from Centaur. Upper stage started its RL-10A engine and began to move satellite into GTO orbit. It was done in three burns. First lasted for 450 seconds and was followed by second burn, which lasted for 250 seconds and was initiated at T+22′. Next Centaur reached highly elliptical orbit with apogee at 32717 km, perigee at 187 km and inclination at 25.7°. For the third burn we were forced to wait three hours – at T+3h 27′ RL-10A was started for the last time and helped Centaur to raise perigee of the orbit for 8000 km in 93 seconds. At T+3h 32′ satellite was deployed on GTO orbit 8137 km x 35290 km inclined at 10.62°. Telemetry data and first self test report confirmed good health of the satellite and on Monday it will start orbit raising on following days. At day 8 of the mission, after five burns of its LEROS-1C Apogee Kick Motor, satellite should reach designated 105°W orbital slot.
GOES-R is weather satellite designed and built by Lockheed Martin for National Oceanic and Atmospheric Administration. With dimensions of 6.1 m x 5.6 m x 3.9 m it weighs 5192 kg (wet) and was based on A2100A modular bus. It is powered with single deployable solar array, which along with onboard batteries, is able to provide power for at least 15 years of planned operational life. It was equipped with Attitude Control System based on reaction wheels and system of thrusters, S band, L band and UHF transponders and data transmitting system able to downlink data with speed of 100 Mbps. Meteorological data will be collected by set of following instruments: Advanced Baseline Imager (ABI) for measuring humidity of clouds, Space Environment In-Situ Suite (SEISS – for monitoring of radiation generated by solar storms), Extreme Ultraviolet Sensor/X-Ray Sensor Irradiance Sensors (EXIS – for detecting solar flares), Solar Ultraviolet Imager (SUVI – telescope for performing observation of ultraviolet wavelength range of sun), Geostationary Lightning Mapper (GLM – near-infrared optical imaging device for detecting lightnings), and Magnetometer (MAG – for monitoring magnetosphere).