Courier 1B,is the world's first activerepeatercommunications satellite, Courier 1B was successfully launched on October 4, 1960 at 17:45:00GMTfrom Cape Canaveral, Florida. The first Courier satellite in Project Courier,Courier 1A,was lost 2.5 minutes after lift-off on August 18, 1960.
 Courier 1 satellite | |
| Mission type | Communications |
|---|---|
| Operator | US Army/ARPA |
| Harvard designation | 1960 NU 1 |
| COSPAR ID | 1960-013A |
| SATCATno. | 00058 |
| Mission duration | 17 days (achieved) 64 years and 22 days (in orbit) |
| Orbits completed | 1000 |
| Spacecraft properties | |
| Manufacturer | Western Development Labs, division ofPhilco |
| Launch mass | 225 kg[1] |
| Power | 60 watts |
| Start of mission | |
| Launch date | 4 October 1960, 17:45:00 GMT |
| Rocket | Thor-Able-Star |
| Launch site | Cape Canaveral,LC-17B |
| Contractor | Douglas/Aerojet |
| End of mission | |
| Last contact | 21 October 1960 |
| Orbital parameters | |
| Reference system | Geocentric[2] |
| Regime | Low Earth |
| Perigee altitude | 938 km |
| Apogee altitude | 1237 km |
| Inclination | 28.33° |
| Period | 106.8 minutes |
| Epoch | 4 October 1960 |
History
editAs a Cold War initiative, Courier 1B was the 26th satellite launched by the US as opposed to the Soviet Union's six satellites since Sputnik I in 1957. Proposed by theUS Army Signal Corpsin September 1958, Courier 1B was a follow-up toSCOREprogram launched December 18, 1958. SCORE "was the first step of an evolutionary program to develop communication satellite systems for use by the military services".[3]TheProject Courierwas a joint program of the USDepartment of Defense(ARPA)along with the USArmy Signal Research and Development LaboratoryatFort Monmouth,New Jersey.
Courier 1B would receive messages or photographs, store them, and then re-transmit them. Courier 1B was:
- An experimental system to demonstrate the feasibility of using satellites for providing a solution to global communications problems. It was designed to store teletype messages and transmit them at high speed while the satellite is in view of a ground station... orbiting Earth at 1,000 kilometres (620 mi).[4]
Spacecraft
editCourier 1B was built by the Western Development Labs (WDL) division ofPhilco,previously known as "Army Fort Monmouth Laboratories". Philco was bought byFord Motor Company,becoming part of itsFord Aerospacedivision, which was acquired byLoral Corporation.WDL then became part ofSpace Systems/Loraldivision ofLoral Space & Communications.IT&T provided ground support equipment and Radiation, Inc, Melbourne, Florida, made the large dish ground antennas. Sonotone Corporation, Elmsford, New York developed the on-board power system for the satellite.
Courier 1B was a 225 kilograms (496 lb), 129.5 centimetres (51.0 in) diameter sphere, 135 kilograms (298 lb) of this was the electronic equipment payload. It carried four 2-W microwave FM (1700-1800 MHz) transmitters and a 50-mW transistorized VHF beacon transmitter subsystem. It contained four solid-state receivers in the 1800-1900 MHz microwave band. Five tape recorders were used to store data for later playback. Four of these were digital with a total capacity of 13.2 Mb (4 minutes at 55 kbit/s) each. One was an analog recorder with a 4-minute capacity and a range of 300 to 50,000 Hz.[1]
Fourwhip antennaswere mounted at 90° intervals along the equator of the sphere. It also held twomicrowave antennas,a transistorized telemetry generator, a VHFdiplexer,and a command decoder. The transmitters and receivers were set up so two of each would be running at any given time, the others were on standby and could be switched in by ground command. The sphere was covered with 19,200 solar cells, charging nickel-cadmium batteries, providing 60 W power. It was the first satellite to use nickel–cadmium storage batteries.[1]
The satellite had the capability to simultaneously transmit, receive, and store approximately 68,000 coded words per minute. It also had real-time communications mode, supporting a single half-duplex voice circuit. The mission was operated by two monitoring stations in New Jersey and Puerto Rico using special 8.5 meters of dish antennas.[1]
Mission
editCourier 1B launched on 4 October 1960 at 17:45:00 GMT from theAtlantic Missile RangeatCape Canaveral,Florida.The launch vehicle was aThor-Able-Star,comprising a modified USAFThor IRBMfirst stage and a USAF Able-Star upper stage with a re-startable liquid engine. The satellite was successfully inserted into an orbit with aperigeeof 938 kilometres (583 mi), anapogeeof 1,237 kilometres (769 mi), aninclinationof 28.33°, and anOrbital periodof 106.8 minutes.[2]Messages were successfully received and transmitted and the satellite operated nominally until a command system failure ended communications 17 days after launch.[1]
After completing a first orbit, a teletype message to theUnited Nations General AssemblyfromPresident of the United StatesDwight D. Eisenhowerwas sent toUnited States Secretary of StateChristian Herter,to be delivered by Herter toFrederick Boland,President of the General Assembly at the United Nations then in session at New York. The message of Eisenhower was transmitted by Courier 1B from the Camp Evans,Deal Test Site,a New Jersey off-base transmission facility ofFort Monmouth.The message was relayed to the Camp Salinas Training Area, a ground station and tracking installation inSalinas,Puerto Rico.If Courier 1B was in sight of the two ground stations at the same time, Courier 1B had the capability of "real time" messaging.[5]
Courier 1B had an effective message transmission rate of 55,000 bits per second and:
Used ultra–high frequency (UHF) communications. This portion of the electromagnetic spectrum had remained relatively unused and generally free from man-made and atmospheric interference. The Courier satellite could simultaneously transmit and receive approximately 68,000 words per minute while moving through space at 16,000 miles per hour, and could send and receive facsimile photographs.[6]
After 228 orbits over 17 days, the payload failed to respond to commands. It was believed that the clock-based access codes got out of synchronization and the satellite would not respond to what it interpreted as unauthorized commands.
See also
edit
References
edit- ^abcde"Courier 1B: Display 1960-013A".nssdc.gsfc.nasa.gov.NASA. 27 February 2020.Retrieved28 April2020.
This article incorporates text from this source, which is in thepublic domain.
- ^ab"Courier 1B: Trajectory 1960-013A".nssdc.gsfc.nasa.gov.NASA. 27 February 2020.Retrieved29 April2020.This article incorporates text from this source, which is in thepublic domain.
- ^T.P. Mottley, D.H. Marx, W.P. Teetsel, "A Delayed - Repeater Satellite Communication System of Advanced Design",IRE Transactions on Military Electronics,Vol. MIL-4, No. 2, April–July 1960. p. 195.
- ^Bartow, James E., Mottley, Thomas P., Teetsel, Walter P. "The Courier Communications System". InTelecommunication Satellites,edited by K.W. Gatland (London: Illife Books LTD., 1964), p. 156.
- ^Bartow, Mottley, Teetsel. "The Courier Communications System". InTelecommunication Satellites,p. 157.
- ^Raines, Rebecca Robbins (1996).Getting the Message Through A Branch History of the US Army Signal Corps(PDF).Washington, D.C.: Center of Military History, US Army. p. 332. Archived fromthe original(PDF)on 2019-10-26.Retrieved2018-05-30.
Further reading
edit- James E. Bartow, Thomas P. Mottley, Walter P. Teetsel, "The Courier Communications Satellite System". InTelecommunication Satellites (Theory, Practice, Ground Stations, Satellites, Economics),edited by K.W. Gatland. pp. 156-183
- T.P. Mottley, D.H. Marx, W.P. Teetsel, "A Delayed-Repeater Satellite Communication System of Advanced Design". InIRE Transactions on Military Electronics,Vol. MIL-4, No. 2, April–July 1960, pp. 195-207. N.B.:IRE Transactions on Military Electronicsis currently published asIEEE Transactions on Aerospace and Electronic Systems
- T. P. Mottley, W. P. Teetsel, P. W. Siglin, "Project Courier Final Report", AD224091, U. S. Army Signal Research and Development Laboratory, Fort Monmouth, New Jersey, July 24, 1961
- Pierce W. Siglin & George Senn, "Courier Communication Satellite". InThe Journal of the Institution of Electrical Engineers,Vol. 7, August 1961, pp. 504-508
- G.F. Senn & P.W. Siglin, "Courier Satellite Communication System". InIRE Transactions on Military Electronics,Vol. MIL-4, No. 4, October 1960, pp. 407-413. N.B.:IRE Transactions on Military Electronicsis currently published asIEEE Transactions on Aerospace and Electronic Systems