FLOCK 1-18 is a CubeSat (3U) satellite owned and operated by Planet Labs (PLABS), originating from the United States. It was launched on November 20, 1998, from the Mid-Atlantic Regional Spaceport (TYMSC) using an Antares 120 launch vehicle from Pad 0A. The satellite measures 0.3 meters in length and has a diameter of 0.1 meters with a span of 0.3 meters. It has a dry mass of 4.25 kilograms, which is the same as its launch mass. Equipped with solar cells and batteries for power, FLOCK 1-18 carries an imaging payload designated as PS0, PS1, or PS2. Its purpose is technology demonstration, and it was designed to operate in orbit for approximately one year when placed in a low Earth orbit (LEO), and potentially up to three years when in Sun-Synchronous Orbit (SSO). The satellite has no propulsion system except for certain variants that may incorporate Field Effect Electric Propulsion (FEEP) technology.