NASA FACTS/A report on the first Relay communications satellite January 14, 1963

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NASA FACTS (G-12-62) Supplement


The first Relay satellite, launched December 13, 1962, could not at first function properly because of an abnormal power drain on its storage batteries. The problems relative to the satellite had been partially resolved by January 3, 1963, making possible the beginning of experiments in transatlantic communication.

On Relay's fifth orbit, some 14 hours after launch, the ground test station at Nutley, New Jersey, checked the satellite's condition. The satellite's voltage was indicated at 22.5, which is below the lower limit of 24 volts required for operation of the communications equipment with- damage to the battery.

The trouble was traced to the voltage regulator in the No. 1 transponder -- the receiving, amplifying, and transmitting apparatus in Relay. Relay is equipped with two identical transponders, each with its own voltage regulator. The voltage regulator channels power to the transponder at a proper voltage and acts as an on-off switch for the transponder.

Telemetry showed that the regulator was conducting power to the transponder even though it was nominally off. As a result, it was partially powering the transponder, and draining the batteries.

Extensive tests and analyses indicated that the main power transistor for the voltage regulator had temperature characteristics that could account for the equipment's malfunction. This transistor fails to function properly if it is too hot or too cold.

Telemetry taken from the satellite on December 15, 17, and 19 showed a slow charging of Relay's batteries. Tests were suspended on the possibility that Relay would recover.

On December 31, a check of the satellite revealed that it was functioning satisfactorily except for a small power drain by voltage regulator No.1.

Because of difficulties experienced with the command system of transponder No.1, project managers decided to employ the other transponder. On January 3, 1963, they activated transponder No.2 and carried out a continuing sequence of transatlantic television, telephone, and teletype communication tests. Some difficulty has been encountered with the command system of the satellite. However, techniques have been developed for satisfactorily commanding the equipment.

Encouraged by the success of the tests, NASA, in cooperation with broadcasting companies of the United States and Europe, scheduled a public telecast via Relay. On January 9, 1963, Relay carried a television program from the National Gallery of Art in Washington, D.C., to stations in France and Great Britain. British and French viewers saw the unveiling of the Mona Lisa painting in the National Gallery and President Kennedy and others who were present at the unveiling ceremony. (Leonardo da Vinci's Mona Lisa was loaned to the United States by France.) Reception in Europe was excellent. The television pictures from the gallery were transmitted conventionally to the Relay ground station at Andover, Maine, from which they were beamed to the satellite for retransmittal to Europe.

A second Relay launch is scheduled in the second quarter of 1963.


The Information In this supplement to NASA FACTS, Project Relay (G-12-62) Incorporates data on results obtained after the fact sheet had been printed. The supplement has been designed for bulletin board display along with the fact sheet, or for punching and looseleaf notebook Insertion as page 9 of NASA FACTS, Project Relay.


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