LEMUR-2-ALEXANDER, also known as Lemur-2-Alexander and designated NORAD_CAT_ID 43559, is a CubeSat (3U) satellite owned by SPIRE. It was manufactured by SPIREG and launched on May 21, 2018, from Wallops Island Spaceport using the Antares 230 launch vehicle. The satellite's dimensions are 0.3 meters in length, 0.1 meters in diameter, and has a span of 0.3 meters. It weighs 4.6 kilograms both at launch and dry mass. Equipped with payloads including STRATOS (GPS radio occultation), SENSE (AIS-receiver), and AirSafe (ASD-B payload starting from #78), the satellite's power is provided by solar cells and batteries. Its shape is described as a box with two panels, and it became stable on July 16, 2018.