AMSAT is a name for various amateur radio satellite organizations worldwide. In particular, it often refers to the Radio Amateur Satellite Corporation, headquartered in Washington, D.C. AMSAT organizations design, build, arrange launches for, and then operate (command) satellites carrying amateur radio payloads, including the OSCAR series of satellites. Other informally affiliated national organizations exist, such as AMSAT Germany (AMSAT-DL) and AMSAT Japan (JAMSAT).
UoSAT-2, which is also known as UO-11 and OSCAR-11, is a British satellite orbiting in Low Earth Orbit. The satellite functions as an amateur radio transmitter and was built at the University of Surrey. It launched into orbit in March 1984 and remains orbital and active, though unstable with irregular periods of transmission. All of the analogue telemetry channels failed in 2005, but as of 2014 the status channels were still operational. The satellite was still heard transmitting telemetry in 2023, thirty-nine years after launch.
In the 19th century, it was observed that the sunlight striking certain materials generates detectable electric current – the photoelectric effect. This discovery laid the foundation for solar cells. Solar cells have gone on to be used in many applications. They have historically been used in situations where electrical power from the grid was unavailable.
A solar cell, also known as a photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect. It is a form of photoelectric cell, a device whose electrical characteristics vary when it is exposed to light. Individual solar cell devices are often the electrical building blocks of photovoltaic modules, known colloquially as "solar panels". Almost all commercial PV cells consist of crystalline silicon, with a market share of 95%. Cadmium telluride thin-film solar cells account for the remainder. The common single-junction silicon solar cell can produce a maximum open-circuit voltage of approximately 0.5 to 0.6 volts.
CUTE-1.7 + APD or CO-56 (Cubesat-Oscar-56) or just OSCAR 56 was an amateur radio satellite in the form of a double CubeSat. The satellite used commercial off-the-shelf components extensively, in particular, it used the Hitachi NPD-20JWL PDA as a control computer, and it used a USB hub for sensor communications. At the end of its mission, the satellite was supposed to deploy an electrodynamic tether to help it deorbit. The satellite failed early into its mission, so the electrodynamic tether experiment probably did not happen. It was launched on February 21, 2006 on board a Japanese launcher M-V.
Spacecraft operating in the inner Solar System usually rely on the use of power electronics-managed photovoltaic solar panels to derive electricity from sunlight. Outside the orbit of Jupiter, solar radiation is too weak to produce sufficient power within current solar technology and spacecraft mass limitations, so radioisotope thermoelectric generators (RTGs) are instead used as a power source.
The STARSHINE series of three artificial satellites were student participatory missions sponsored by the United States Naval Research Laboratory.
The Atmospheric Neutral Density Experiment (ANDE) is an experiment using two spherical satellites to measure the effects of atmospheric drag on spacecraft. ANDE is part of the Space Test Program of the United States Department of Defense, and was deployed in September 2006 from the Space Shuttle Discovery.
The United States Naval Academy (USNA) Small Satellite Program (SSP) was founded in 1999 to actively pursue flight opportunities for miniature satellites designed, constructed, tested, and commanded or controlled by Midshipmen. The Naval Academy's aerospace laboratory facilities are some of the most advanced and extensive in the country. These facilities include structures labs, propulsion and rotor labs, simulation labs, wind tunnels with flow velocities ranging from subsonic to supersonic, computer labs, and the Satellite Ground Station. The SSP provides funds for component purchase and construction, travel in support of testing and integration, coordination with The US Department of Defense or National Aeronautics and Space Administration (NASA) laboratories or with universities for collaborative projects, and guides Midshipmen through the Department of Defense (DoD) Space Experiments Review Board (SERB) flight selection process.
AMSAT-OSCAR 7, or AO-7, is the second Phase 2 amateur radio satellite constructed by the Radio Amateur Satellite Corporation (AMSAT). It was launched into Low Earth Orbit on November 15, 1974 and remained operational until a battery failure in 1981. After 21 years of apparent silence, the satellite was heard again on June 21, 2002 – 27 years after launch. At that time the public learned that the satellite had remained intermittently functional and was used surreptitiously for communication by the anticommunist opposition Fighting Solidarity during martial law in Poland.
Delfi-C3 is a CubeSat satellite constructed by students at the Delft University of Technology in the Netherlands. It is a 3-unit CubeSat, and was launched at 03:53:42 on 28 April 2008, as part of the NLS-4 mission, aboard a PSLV rocket, from the Second Launch Pad at the Satish Dhawan Space Centre in India. The launch was contracted by ISRO, through Antrix Corporation and UTIAS.
Concentrator photovoltaics (CPV) is a photovoltaic technology that generates electricity from sunlight. Unlike conventional photovoltaic systems, it uses lenses or curved mirrors to focus sunlight onto small, highly efficient, multi-junction (MJ) solar cells. In addition, CPV systems often use solar trackers and sometimes a cooling system to further increase their efficiency.
An amateur radio satellite is an artificial satellite built and used by amateur radio operators. It forms part of the Amateur-satellite service. These satellites use amateur radio frequency allocations to facilitate communication between amateur radio stations.
OSCAR 3 is the third amateur radio satellite launched by Project OSCAR into Low Earth Orbit. OSCAR 3 was launched March 9, 1965 by a Thor-DM21 Agena D launcher from Vandenberg Air Force Base, Lompoc, California. The satellite, massing 15 kg (33 lb), was launched piggyback with seven United States Air Force satellites. Though the satellite's active life was limited to sixteen days due to battery failure, OSCAR 3 relayed 176 messages from 98 stations in North America and Europe during its 274 orbit life-time -- the first amateur satellite to relay signals from Earth. As of 2025, it is still in orbit.
OSCAR IV was the fourth amateur radio satellite launched by Project OSCAR and the first targeted for Geostationary orbit on 12 December 1965. The satellite was launched piggyback with three United States Air Force satellites on a Titan IIIC launch vehicle. Due to a booster failure, OSCAR 4 was placed in an unplanned and largely unusable Geostationary transfer orbit.
There are many practical applications for solar panels or photovoltaics. From the fields of the agricultural industry as a power source for irrigation to its usage in remote health care facilities to refrigerate medical supplies. Other applications include power generation at various scales and attempts to integrate them into homes and public infrastructure. PV modules are used in photovoltaic systems and include a large variety of electrical devices.
PANSAT was an amateur radio satellite. It was launched by Space Shuttle Discovery during the STS-95 mission as part of the third International Extreme Ultraviolet Hitchhiker (IEH-3) mission, on 30 October 1998 from Kennedy Space Center, Florida.
Starshine 3 is one of five satellites in the Starshine project.
Radar Fence Transponder was an amateur radio satellite that was developed and built for training purposes at the United States Naval Academy. The 3 kg (6.6 lb) heavy RAFT had a cubic structure of 12.7 cm (5.0 in) edge length and therefore did not meet the Cubesat standard. Solar cells on all six sides of the satellite were used to supply energy. It had neither position control nor drive systems.
A zombie satellite is a satellite that begins communicating again after an extended period of inactivity. It is a type of space debris, which describes all defunct human-made objects in outer space. At the end of their service life, the majority of satellites suffer from orbital decay and are destroyed by the heat of atmospheric entry. Zombie satellites, however, maintain a stable orbit but are either partially or completely inoperable, preventing operators from communicating with them consistently.
