10 08 15


Dual Frequency Ionospheric Calibration Measurements

Beacons Of Innovation

The PropCube (Propagation CubeSat) series of 1U CubeSats are ionospheric research satellites to measure artificial ionization.

Terran orbital built the spacecraft, integrated the customer-designed payload, and helped to commission the spacecraft.

The CubeSats perform dual frequency ionospheric calibration measurements of ionospheric electron density and irregularities. They perform measurements of total electron content by differential group delay, of plasma irregularities by amplitude and phase scintillations, and detection of artificial ionization and irregularities generated by the HAARP, Arecibo, and Sura high-frequency facilities.

PropCube 1 (Fauna) and PropCube 3 (Merryweather) were launched together into a 63° orbit.

Flora and Merryweather transmit critical calibration beacons to improve communications systems. These signals were sent to Earth-based receiver sites, including Arecibo Observatory, Puerto Rico, and HAARP, Alaska, to collect data. This mission was also used to test the Naval Postgraduate School’s Mobile CubeSat Command & Control (MC3) ground station network.​

Originally developed in 2012, Terran Orbital’s Intrepid 1U platform has been an industry benchmark and is considered the main turning point in the commercialization of CubeSats. ​






Naval Postgraduate School


1U Satellite

Launch Date

October 8, 2015

Launch Vehicle

Atlas V

Mission Length


Mission Completion


Atlas V

An expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Martin and Boeing. Atlas V is also a major NASA launch vehicle. In August 2021, ULA announced that Atlas V would be retired, and all 29 remaining launches had been sold. As of 2 July 2022, 22 launches remain, and it is the oldest active American rocket to this day.

Each Atlas V launch vehicle consists of two main stages. The first stage is powered by a Russian RD-180 engine manufactured by Energomash and burning kerosene and liquid oxygen. The Centaur upper stage is powered by one or two American RL10 engine(s) manufactured by Aerojet Rocketdyne and burns liquid hydrogen and liquid oxygen. The Star 48 upper stage was used on the New Horizons mission as a third stage. Strap-on solid rocket boosters (SRBs) are used in most configurations. AJ-60A SRBs were used originally, but they were replaced in November 2020 by Graphite-Epoxy Motor (GEM 63) SRBs. The standard payload fairings are 4.2 or 5.4 m (14 or 18 ft) in diameter with various lengths.

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