FLOCK 4S-19 is a CubeSat (3U) satellite manufactured by PLAN and owned by the same entity. Launched on January 24, 2021, from LC40 at AFETR using a Falcon 9 launch vehicle, this satellite has dimensions of 0.3 meters in length with a diameter of 0.1 meters and a span of 0.3 meters. It weighs 5.7 kg both at launch and dry mass. Equipped with PS0, PS1 or PS2 imaging payload named Dove 242d, its primary mission is technology demonstration. FLOCK 4S-19 relies on solar cells and batteries for power and has a box shape with two panels. It operates in an ISS orbit with an expected lifetime of approximately one year or between two to three years in sun-synchronous orbit (SSO).