It was busy time for NASA, SpaceX and United Launch Alliance. ULA managed to deliver to orbit WGS-9 military communications satellite on the top of the Delta IV, NASA and SpaceX performed successfully unberthing of Dragon cargo spacecraft from International Space Station.
Launch of Delta IV was planned as part of program of updating communications system of U.S Army along with partner countries: Canada, Denmark, the Netherlands, Luxembourg and New Zealand. Rocket with Wideband Global SATCOM was launched on Sunday, March 19, at 00:18 UTC from Space Launch Complex 37B at Cape Canaveral. Worth $424 million satellite was launched on the top of the Delta IV Medium+ supported with four Solid Rocket Boosters and long for 66 m with 5 m wide payload fairing. Launch was originally planned for Saturday, unfortunately countdown was hold to let specialists from United Launch Alliance to solve minor issues with ground infrastructure. Finally at 00:18 on Sunday UTC, Delta IV started engines and begun to rise over launch pad. Clearly visible over dark sky (weather forecast was almost 100% for "go"), Delta reached maximum dynamic pressure point at T+46" and let boosters to fall on the ground at T+1'42". First stage was cut off at T+3'56"; second stage started to burn and delivered WGS-9 to 185 km x 6085 km orbit at T+20'. Second burn was performed at T+29'30" and after nine minutes Delta Cryogenic stage with its RL-10B engine was cut off. As it was planned WGS-9 was deployed at T+42 over Indian Ocean on 435 km x 44350 km and inclined at 27.00° degrees orbit.
Also in Sunday SpaceX with NASA performed successful unberthing CRS-10 Dragon cargo spacecraft from Harmony module Earth facing berthing port, where remained since February 19, 2017. During previous days, astronauts packed pressurized section of Dragon with 2450 kg of samples and scientific material which should return to Earth. Trunk section, which burns during destructive reentry, was loaded with unwanted hardware and trash. Finally after closing hatch and leak tests, latches of berthing port were released at 21:20 UTC on Saturday. In following hours Canadarm2 moved Dragon to release position remotely. Shane Kimbrough (NASA) and Thomas Pesquet (ESA) were ready to release Dragon from Canadarm2 in the morning hours. Finally Dragon start its return to Earth at 09:11 UTC and performed three burns to reach safe distance from ISS. After reaching distance of 150 km, Dragon was already controlled by specialists from SpaceX flight control center in Hawthorne. At around 13:55 UTC Dragon started its lasting for around 20 minutes deorbit burn and released cargo trunk at 14:12 UTC. Thirteen seconds later Dragon hit into dense layers of atmosphere and using Draco thrusters managed to keep correct orientation to Earth and make possible deployment of parachutes. On altitude of 13:7 km three drag parachutes was deployed and after reducing speed from 240 m/s to 20 km/h splash into Pacific at 14:46 UTC 400 km from Baja in California.