A pair of nanosatellites were deployed by the NanoRacks Launcher on the end of the Japanese robotic arm of the International Space Station on Friday. The tiny CubeSats are loaded with tools to observe the planet.
CubeSats are NASA's nanosatellite program for lightweight, self-contained experiments that can fly as small auxiliary payloads on planned launches. A few are tucked into most cargo runs to the space station, an added bonus of science to the regular payload. This particular batch are another flock of the Planet Labs Doves, a series of etched observer satellites intended to provide frequent full-Earth coverage.
The NanoRack Launch is only releasing the satellites when an astronaut tells it to. Finally. Image credit: NASA/Butch Wilmore
The Dove satellites are about triple the length of the normal cube-shaped satellites: 10 centimetres per side by 30 long, weighing under 6 kilograms. Lacking in sophisticated orbital stabilizing equipment, CubeSats are in decaying orbits and typically only remain in space for a few months to years before burning up in the atmosphere. Doves are no different, carrying only a reaction wheel to stabilize their orbits.
CubeSats deployed from a now-functional NanoRacks Launcher on February 27, 2015. Image credit: NASA/Butch Wilmore
Last time we checked in on the CubeSats, the NanoRack Launcher was spontaneously launching them from the space station without astronaut intervention. The root cause of the malfunction was overly tightened dispenser screws. Since it was replaced, it has been functioning normally, only releasing satellites at the request of its controlling astronauts.
CubeSats against the dramatic backdrop of space. Image credit: NASA/Butch Wilmore