The Northrop Grumman Cygnus NG-10 (John Young) unmanned cargo spacecraft, whose operation has been commission by NASA, having earlier been “unberthed” from the Unity module using the International Space Station’s robot arm, it was released at 1616 GMT on 8 February 2019. After departing made two burns to raise orbit ready for its deployment of the cubesats it was carrying as part of its secondary mission.
In addition a new “Slingshot” deployer had been fitted to the Cygnus NG-10 spacecraft on 7 February (it had been carried to the ISS on board Dragon CRS-16) to allow the SEOPS pair of radar cubesats fitted to the deployer, Quantum Radar 1 and 2, to be released.
This release happened on 9 February at circa 1530 GMT.
Update on 15 February 2019: Chefsat 2 and Mysat-1 were released from dispenser on Cygnus NG-10 (John Young) at 1200 GMT on 13 February 2019. Kicksat 2 (with Sprite 105 Femtosat Formation (Stanford) aboard was released from their dispenser on at 2245 GMT on 13 February 2019.