In the early morning hours on Friday, August 25, Orbital ATK Minotaur-4 rocket delivered to orbit military satellite and three experimental CubeSat satellites from Space Launch Complex 46 at Cape Canaveral Air Force Station.
Main objective of this mission was delivering to orbit experimental military satellite with ability of scanning GEO belts from low earth orbit from altitude of only 700 km. Satellite like SkySat Earth could cost many times less comparing to GEO orbit (not to mention about cost of delivering to orbit) satellites and still could scan and track objects placed on GEO orbit. Potential objects, which could be tracked are other communications satellites and pieces of the space debris. Information gathered by SkySat Earth will be useful for correcting course of the satellites to avoid collisions with space debris.
Rocket as totally solid fueled was assembled at launch pad in vertical position on last Friday, August 19.
Rocket started its first stage punctually at 06:02 UTC on Friday August 26. After 35 seconds of flight rocket passed Max Q point, where dynamic pressure reaches peak value. At T+1' first stage burned all the propellant and was jettisoned. After another 60 seconds second stage was also jettisoned and at T+2'30" payload fairing was released. After another 50 seconds third stage burned all the propellant and rocket begun to coast on altitude of 570 km. Orion-38, fourth stage of the Minotaur-4, ignited at T+14' for 67 seconds. After burn was completed, rocket entered again into ballistic phase of flight and reached at T+17' preliminary parking orbit. At T+20' rocket deployed two Prometheus CubeSats for Los Alamos National Laboratory and the CubeSat for DARPA. At T+25' last burn of Orion-38 was started to reduce inclination to zero and put upper stage with satellite to almost circular orbit (604 km x 59 km). After another three minutes satellite was deployed from Orion-38. Orbital ATK and the U.S. Air Force confirmed after two hours satellite was released correctly.