Please, pay! ARPA message at 55 kilobits/s: Launch of satellite communication
Courier 1B, launched in 1960, was the first communication satellite with solar cells and a relay station. Besides lots of technology, it carried a message too.
On October 4, 1960, a Thor rocket carried the first US communication satellite, Courier 1B, into orbit. The 225-kilogram sphere, equipped with 19,200 solar cells and nickel-cadmium batteries, communicated with the two ground stations, Camp Evans (New Jersey) and Camp Salinas (Puerto Rico), for 17 days. Courier 1B is considered the first modern communication satellite: it functioned for the first time both as a relay for direct communication between stations and as temporary storage using the store-and-forward method: four digital mini-recorders could each record and play back 4 minutes at a transmission speed of 55,000 bits per second, or 55 kbit/s. This corresponded to a maximum capacity of 13.2 megabytes per recorder.
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Encrypted conversations and data were transmitted. Among other things, a fax transmission was successful. Another analog mini-recorder with a 4-minute capacity transmitted a greeting from President Dwight Eisenhower to the United Nations General Assembly in New York after its first orbit.
ARPA Lab in Response to Sputnik Shock
Courier 1B, which, with its distinctive spherical shape, reminds many Star Wars enthusiasts of an imperial interrogation droid, was one of the most successful satellite projects of the military research agency ARPA (from 1972: DARPA). While ARPA is generally associated with the development of the internet, it is somewhat forgotten that the agency launched numerous satellite projects. It acted very agilely: ARPA experts outlined the requirements, and then various companies were commissioned to develop the components. The Signal Research and Development Laboratory (SRDL) of ARPA was responsible for the satellite projects, located at Fort Monmouth. The laboratory was created immediately after the Sputnik shock.
Courier 1A was a failed launch: the rocket exploded two and a half minutes after launch on August 18, 1960. The Courier program, developed by SRDL, had a predecessor called SCORE. This “Signal Communications by Orbiting Relay Equipment” was built into an Atlas rocket launched on December 18, 1958. The communication module was powered by a battery that functioned for 13 days and transmitted a speech by President Eisenhower, a kind of Christmas message in which he affirmed the wish for peace all over the world. The relatively weak signal could only be heard (and interfered with) by amateur radio operators with powerful receivers and by professional listeners from other countries; Eisenhower's speech was later distributed by press agencies worldwide.
(Image:Â USGov-Military-Army)
The solar cells supplied the transmitters in the sphere with 60 W of power; four antennas ensured optimal reception in the 1800-1900 MHz range and transmission in the 1700-1800 MHz range. Unlike SCORE, the signal was encrypted and achieved an output of 55 kbit/s while simultaneously transmitting, receiving, and storing. After 228 orbits, or 17 days, Courier 1B no longer responded to commands from the ground stations, which it apparently rejected as unauthorized communication. In total, Courier IB is said to have transmitted the equivalent of 50 million telex words as a relay. Although Courier 1C was produced, it was not sent into space—instead, it was replaced by Telstar.
Spy Satellites Above Any Air Defense
Against the backdrop of the Cold War, the development of satellites was important in another respect. In May 1960, the Soviet Union had finally managed to shoot down one of the U2 aircraft that flew over the country at an altitude of 20,000 meters. Pilot Gary Powers was able to parachute to safety but was captured and presented publicly. President Eisenhower subsequently prohibited the U2 overflights, which he had to approve individually.
However, together with the CIA, ARPA had begun to develop a series of satellites, the Project Corona, which photographed the Soviet Union during overflights at high altitude and dropped the exposed film rolls by parachute after the overflight. The photos were later used in the SALT arms reduction negotiations with the Soviet Union. The collaboration between the CIA and ARPA was highly secret and was only made public in 1995 under President Bill Clinton.
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It was completely different with the ARPA Project Vela, which was designed for public presentation from the outset, although several technical details were omitted. Vela (Spanish for guardian) was intended to monitor the entire Earth and report when a country tests nuclear weapons. In space, Vela Hotel satellites searched for suspicious radiation, while Vela Sierra on the ground and Vela Uniform searched for seismic activities that would shake the planet after a nuclear bomb explosion. A total of 12 Vela Hotel satellites were built by TRW on behalf of ARPA and monitored the Earth from an altitude of 118,000 kilometers for 26 years.
On September 22, 1979, Vela satellites registered a flash of light in the Indian Ocean, which presumably indicated a nuclear weapons test by South Africa or Israel. In any case, Vela made it possible for the Limited Test Ban Treaty (LTBT) to come into force in 1963, signed by the USA, Great Britain, and the Soviet Union. (In German: “Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water”).
(mki)
