Perfectly prepared and perfectly conducted – ULA against showed class during launch of WorldView-4 imaging satellite with piggyback payload of seven Cubesat satellites.
This launch was postponed for two months due the huge fire devastating forests around Vandenberg Air Force Base. Atlas V with WorldView-4 luckily remained untouched, just as launch facilities and launch pad. Yesterday, at Space Launch Complex 3 everything was ready and even weather was perfect with literally zero probability of launch interruption announced at 06:00 GMT. Launch was set for 10:30 local time (18:30 GMT). Atlas V in 401 configuration was already exposed after Mobile Service Tower was moved four hours before launch. At 18:00 GMT rocket was after fueling procedure and was waiting to finish full test of all subsystems. In 401 version Atlas V was equipped with payload fairing with diameter of 4 m, no solid rocket boosters and single engine installed in Centaur upper stage. Yesterday’s mission assumed launch, course correction to head south west and delivering operated by DigitalGlobe WorldView-4 imaging satellite to SSO orbit with altitude 617 km. Next after two hours rocket should remain on orbit to finish mission with deploying seven piggyback Cubesat satellites.
About T-4′ final status check were performed and mission was set to “go”. Finally ten seconds before launch water curtains were initialized and rocket start its first stage propulsion. Punctually at 18:30 GMT Atlas V started to rise over SLC-3 using its RD-180 burning almost 285 t of RP-1/LOX and generating 3827 kN of thrust. Speed of sound and point where rocket is under highest dynamic pressure were reached at T+1’17”. Rocket started to change its course to SW and at 18:35 GMT RD-180 was cut off. Shortly after first stage was separated and Centaur ignited its RL-10C-1 engine on altitude of 213 km. It provided thrust of 110 kN burning LH2/LOX. At T+4’27” payload fairing was jettisoned. Centaur performed cut off of its engine at 18:47 GMT; next it rotated for 180 degrees to continue flight with WorldView-4 faced to Earth until deploying satellite at T+19’37” on altitude of 624 km. After that it continued flight for almost two hours to reach correct position to deploy seven Cubesat satellites remaining in deployment device on the bottom of Centaur upper stage. First two satellites were deployed at T+ 2h 12′ 04″ over South Pole on altitude of around 620 km. Next pair was pushed from deployment device three minutes later. Last deployment took place eight minutes later.
WorldView-4 is small imaging satellite designed by Lockheed Martin (basing on LM-900) in the cooperation of TTI (payload). With weight of 2600 kg designed to operate from 617 km SSO orbit being powered by two deployable solar arrays and onboard batteries. It will operate for at least 12 years; it will take high resolution pictures using onboard GIS-2 imaging unit providing ground resolution of 0.34 m. Cubesat satellites delivered today were RAVAN, U2U, Aerocube 8-C, Aerocube-8D, Prometheus-2.1, Prometheus-2.2 and CELTEE-1. RAVAN (Radiometer Assessment Using Vertically Aligned Nanotubes) was manufactured by Blue Canyon Technologies for measuring radiation emitted by Earth using special nanotubes. It will be operated by the Applied Physics Laboratory at Johns Hopkins University. RAVAN weighs around 6 kg with dimensions of 1.5 standard Cubesat; it will operate for 6 months. Both Prometheus satellites were designed by Los Alamos National Laboratory (LANL) as 1.5U sized Cubesats with weight of 2 kg and powered by four deployable solar arrays. During their lasting at least 2 years mission they will test various communication technologies. Both AeroCube are 1.5U Cubesats designed to test ion propulsion. Last two are CELTEE and U2U developed by US Air Force Research Laboratory. CELTEE was designed as 1U Cubesat to test Enhanced Location Transponder (ELT) M42 Technologies; U2U is 2U sized and is carrying Electron science experiment onboard.