A CubeSat is a type of miniaturized satellite for space research that usually has a volume of exactly one liter (10 cm cube), has a mass of no more than 1.33 kilograms, and typically uses commercial off-the-shelf components for its electronics.
Beginning in 1999, California Polytechnic State University (Cal Poly) and Stanford University developed the CubeSat specifications to help universities worldwide to perform space science and exploration.
The CubeSat specification accomplishes several high-level goals. Simplification of the satellite’s infrastructure makes it possible to design and produce a workable satellite at low cost. Encapsulation of the launcher–payload interface takes away the prohibitive amount of managerial work that would previously be required for mating a piggyback satellite with its launcher. Unification among payloads and launchers enables quick exchanges of payloads and utilization of launch opportunities on short notice.
Since CubeSats are all 10×10 cm (regardless of length) they can all be launched and deployed using a common deployment system. CubeSats are typically launched and deployed from a mechanism called a Poly-PicoSatellite Orbital Deployer (P-POD), also developed and built by Cal Poly. P-PODs are mounted to a launch vehicle and carry CubeSats into orbit and deploy them once the proper signal is received from the launch vehicle. P-PODs have deployed over 90% of all CubeSats launched to date (including un-successful launches), and 100% of all CubeSats launched since 2006. The P-POD Mk III has capacity for three 1U CubeSats, or other 1U, 2U, or 3U CubeSats combination up to a maximum volume of 3U.
QB50 is a proposed international network of 50 CubeSats for multi-point, in-situ measurements in the lower thermosphere (90–350 km) and re-entry research. QB50 is an initiative of the Von Karman Institute and is funded by the European Commission as part of the 7th Framework Programme (FP7). Double-unit (2U) CubeSats (10×10×20 cm) are developed, with one unit (the ‘functional’ unit) providing the usual satellite functions and the other unit (the ‘science’ unit) accommodating a set of standardised sensors for lower thermosphere and re-entry research. 35 CubeSats are envisaged to be provided by universities in 19 European countries, 10 by universities in the US, 2 by universities in Canada, 3 by Japanese universities, 1 by an institute in Brazil, and others. Ten 2U or 3U CubeSats are foreseen to serve for in-orbit technology demonstration of new space technologies.
The Request for Proposals (RFP) for the QB50 CubeSat was released on February 15, 2012. Two “precursor” QB50 satellites were launched aboard a Dnepr rocket on June 19, 2014. All 50 CubeSats were supposed to be launched together on a single Cyclone-4 launch vehicle in February 2016, but due to the unavailability of the launch vehicle, 40 satellites are now planned to be launched aboard Cygnus CRS OA-7 in March 2017 and subsequently deployed from the ISS. Eight other cubesats have been manifested on two further Dnepr flights but the availability of this launcher has been in doubt since its last flight in 2015.
2018 InSight mission: MarCO CubeSats
The May 2018 launch, of the InSight stationary lander to Mars, will include two CubeSats to flyby Mars to provide additional relay communications from InSight to Earth during entry and landing. This will be the first flight of CubeSats in deep space. The mission CubeSat technology is called Mars Cube One (MarCO), a six-unit CubeSat, 14.4 inches (36.6 centimeters) by 9.5 inches (24.3 centimeters) by 4.6 inches (11.8 centimeters). MarCo is an experiment, but not necessary for the InSight mission, to add relay communications to space missions in important time durations, in this landing from the time of InSight atmospheric entry and landing.
MarCO will launch in May 2018 with the InSight lander and will separate after launch and then travel in their own trajectories to Mars. After separation, MarCO will deploy two radio antennas and two solar panels. The high-gain, X-band antenna is a flat panel to direct radio waves. MarCO will navigate to Mars independently from the InSight lander, making their own course adjustments on the flight.
During InSight’s planned entry, descent and landing (EDL) in November 2018, the lander will transmit information in the UHF radio band to NASA’s Mars Reconnaissance Orbiter (MRO) flying overhead. MRO will forward EDL information to Earth using a radio frequency in the X band, but cannot simultaneously receive information in one band if transmitting on another. Confirmation of a successful landing could be received on Earth several hours after, so MarCO would be a technology demonstration of real-time telemetry during the landing.
InSight lander with labeled instruments
Sources: Wikipedia and National Geographic