Morse code is a telecommunications method which encodes text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs. Morse code is named after Samuel Morse, one of the early developers of the system adopted for electrical telegraphy.
Mariner 1, built to conduct the first American planetary flyby of Venus, was the first spacecraft of NASA's interplanetary Mariner program. Developed by Jet Propulsion Laboratory, and originally planned to be a purpose-built probe launched summer 1962, Mariner 1's design was changed when the Centaur proved unavailable at that early date. Mariner 1, were then adapted from the lighter Ranger lunar spacecraft. Mariner 1 carried a suite of experiments to determine the temperature of Venus as well to measure magnetic fields and charged particles near the planet and in interplanetary space.
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit 22,236 miles (35,785 km) above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently.
The RM-81 Agena was an American rocket upper stage and satellite bus which was developed by Lockheed Corporation initially for the canceled WS-117L reconnaissance satellite program. Following the division of WS-117L into SAMOS and Corona for image intelligence, and MIDAS for early warning, the Agena was later used as an upper stage, and an integrated component, for several programs, including Corona reconnaissance satellites and the Agena Target Vehicle used to demonstrate rendezvous and docking during Project Gemini. It was used as an upper stage on the Atlas, Thor, Thorad and Titan IIIB rockets, and considered for others including the Space Shuttle and Atlas V. A total of 365 Agena rockets were launched between February 28, 1959 and February 1987. Only 33 Agenas carried NASA payloads and the vast majority were for DoD programs.
The SAMOS or SAMOS-E program was a relatively short-lived series of reconnaissance satellites for the United States in the early 1960s, also used as a cover for the initial development of the KH-7 GAMBIT system. Reconnaissance was performed with film cameras and television surveillance from polar low Earth orbits with film canister returns and transmittals over the United States. SAMOS was first launched in 1960 from Vandenberg Air Force Base.
AMSAT-OSCAR 51 or AO-51 is the in-orbit name designation of a now defunct LEO amateur radio satellite of the OSCAR series; formerly known as ECHO, built by AMSAT. It was launched on June 29, 2004 from Baikonur Cosmodrome, Kazakhstan on a Dnepr launch vehicle. It is in Sun synchronous low Earth orbit.
An amateur radio station is a radio station designed to provide radiocommunications in the amateur radio service for an amateur radio operator. Radio amateurs build and operate several types of amateur radio stations, including fixed ground stations, mobile stations, space stations, and temporary field stations. A slang term often used for an amateur station's location is the shack, named after the small enclosures added to the upperworks of naval ships to hold early radio equipment and batteries.
Badr-1 was the first artificial and the first digital communications satellite launched by Pakistan's national space authority — the SUPARCO — in 1990. The Badr-1 was Pakistan's first indigenously developed and manufactured digital communications and an experimental artificial satellite which was launched into low Earth orbit by Pakistan on 16 July 1990, through a Chinese carrier rocket. The launch ushered new military, technological, and scientific developments in Pakistan and also provided data on radio-signal distribution in the ionosphere. Originally planned to be launched from the United States in 1986, the Challenger disaster further delayed the launch of the satellite which changed the plan. After the People's Republic of China offered Pakistan to use its facility, the Badr-1 was finally launched from Xichang Satellite Launch Center in 1990 on Long March 2E. Badr-1 travelled at 17,500 miles per hour (28,200 km/h), taking 96.3 minutes to complete an orbit, and emitted radio signals at the 145 to 435 MHz bands which were operated by Pakistan Amateur Radio Society (PARS). The Badr-1 successfully completed its designed life, and a new satellite was proposed to be developed.
W1AW is both the amateur radio call sign and the primary operating station of the American Radio Relay League (ARRL). This station, which is commonly called the Hiram Percy Maxim Memorial Station, is located on the grounds of ARRL Headquarters in Newington, Connecticut. It was inspired by Maxim's 1AW callsign which predated the use of the AA-AL, K, N and W prefixes. The station routinely transmits bulletins and Morse code practice using common amateur radio frequencies. During a communications emergency bulletins are transmitted hourly in order to keep amateur radio operators informed.
William Ittner Orr (1919–2001) was an engineer, educator, communicator, and ham radio operator. He was the American author of numerous amateur radio and radio engineering texts. He is best known as the author of The W6SAI Antenna Handbook and fondly remembered for the 1959 Radio Handbook.
The STARSHINE series of three artificial satellites were student participatory missions sponsored by the United States Naval Research Laboratory.
Atlas is a family of US missiles and space launch vehicles that originated with the SM-65 Atlas. The Atlas intercontinental ballistic missile (ICBM) program was initiated in the late 1950s under the Convair Division of General Dynamics. Atlas was a liquid propellant rocket burning RP-1 kerosene fuel with liquid oxygen in three engines configured in an unusual "stage-and-a-half" or "parallel staging" design: two outboard booster engines were jettisoned along with supporting structures during ascent, while the center sustainer engine, propellant tanks and other structural elements remained connected through propellant depletion and engine shutdown.
SAMOS-F or Air Force Program 102 refers to a series of SIGINT reconnaissance satellites launched and operated by the United States Air Force and National Reconnaissance Office during the 1960s. Initial priorities were to monitor radio waves in the frequency bands 2.5-3.2 GHz, 9.0–10 GHz, and 59-650 MHz. The intercepted data and their location were stored on magnetic tape, and subsequently transmitted to tracking and acquisition ground stations. Tracking stations were located in the NE, Central, and NW of the continental United States, with additional test sites at Vandenberg AFB, California, and at Ka'ena Point, Oahu, Hawai. The satellites are also called Agena ferrets and heavy ferrets. Approximately sixteen heavy ferrets were launched into low Earth orbits from Vandenberg Air Force Base between February 1962 and July 1971 aboard Thor-Agena and Thorad-Agena rockets. Almost everything about these satellites remains classified.
The Missile Defense Alarm System, or MIDAS, was a United States Air Force Air Defense Command system of 12 early-warning satellites that provided limited notice of Soviet intercontinental ballistic missile launches between 1960 and 1966. Originally intended to serve as a complete early-warning system working in conjunction with the Ballistic Missile Early Warning System, cost and reliability concerns limited the project to a research and development role. Three of the system's 12 launches ended in failure, and the remaining nine satellites provided crude infrared early-warning coverage of the Soviet Union until the project was replaced by the Defense Support Program. MiDAS represented one element of the United States's first generation of reconnaissance satellites that also included the Corona and SAMOS series. Though MIDAS failed in its primary role as a system of infrared early-warning satellites, it pioneered the technologies needed in successor systems.
AMSAT-OSCAR 16, also known as AO-16 and PACSAT, is the in-orbit name designation of an amateur radio satellite of the OSCAR series. It was built by AMSAT and was launched on 22 January 1990 from Kourou, French Guiana on an Ariane 4 launch vehicle. It is in Sun synchronous low Earth orbit.
Discoverer 36, also known as Corona 9029, was an American optical reconnaissance satellite which was launched in 1961. It was a KH-3 Corona satellite, based on an Agena-B rocket. It was the penultimate KH-3 satellite to be launched, the last successful mission, and the most successful of the program.
Australis-OSCAR 5 is an amateur radio satellite that was launched into Low Earth Orbit on 23 January 1970 by a Thor Delta launcher from Vandenberg Air Force Base, Lompoc, California. AO-5 was launched piggyback with TIROS-M (ITOS-1) weather satellite).
OSCAR 2 is the second amateur radio satellite launched by Project OSCAR into Low Earth orbit. OSCAR 2 was launched June 2, 1962, by a Thor-DM21 Agena B launcher from Vandenberg Air Force Base, Lompoc, California. The satellite, a rectangular box weighing 10 kg (22 lb), was launched as a secondary payload (ballast) for Corona 43, the fifth launch of a KH-4 satellite.
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 2023, 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.
