Encyclopedia Astronautica
Echo



echo.jpg
Echo
Credit: NASA
American passive communications satellite. 2 launches, 1960.05.13 (Echo 1) and 1960.08.12 (Echo 1). The Echo satellites were NASA's first experimental communications satellite project.

Each spacecraft was a large metallized balloon designed to act as a passive communications reflector to bounce communication signals transmitted from one point on Earth to another.

Following the failure of the launch vehicle carrying Echo 1, Echo 1A (commonly referred to as Echo 1) was successfully orbited, and was used to redirect transcontinental and intercontinental telephone, radio, and television signals. The success of Echo 1A proved that microwave transmission to and from satellites in space was understood and demonstrated the promise of communications satellites. The vehicle also provided data for the calculation of atmospheric density and solar pressure due to its large area-to-mass ratio. Echo 1A was visible to the unaided eye over most of the Earth (brighter than most stars) and was probably seen by more people than any other man-made object in space. Echo 2 continued the passive communications experiments, and also investigated the dynamics of large spacecraft and was used for global geometric geodesy. Although NASA abandoned passive communications systems in favor of active satellites following Echo 2, the Echo systems demonstrated several ground station and tracking technologies that would be used by active systems. Echo 1A re-entered on May 24, 1968 followed by Echo 2 on June 7, 1969.

Echo 1 and 1A were 30.5 m diameter balloons made of 0.0127 mm thick mylar polyester film. A set of 107.9-MHz beacon transmitters were carried for telemetry. The transmitters were powered by five nickel-cadmium batteries that were charged by 70 solar cells mounted on the balloon. Echo 2 was a 41.1 m diameter mylar balloon that used an improved inflation system to improve the balloon's smoothness and sphericity. Instrumentation included temperature sensors to monitor the balloon's skin temperature and pressure sensors to monitor the balloon's internal pressure. A beacon system, consisting of two transmitter assemblies, provided tracking and telemetry signals. The beacon system used solar cell panels for power and had a minimum power output of 45 mW at 136.17 MHz and 136.02 MHz. No scientific payloads were carried on any of the missions. Echo 1's surface was used to reflect 960 and 2390 Mhz signals. Echo 2 experimenters utilized 162 Mhz signals.

Gross mass: 66 kg (145 lb).
Height: 41.10 m (134.80 ft).
First Launch: 1960.05.13.
Last Launch: 1960.08.12.
Number: 2 .

More... - Chronology...


Associated Countries
See also
  • Delta The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Development began in 1955 and it continued in service in the 21st Century despite numerous candidate replacements. More...

Associated Launch Vehicles
  • Delta American orbital launch vehicle. The Delta launch vehicle was America's longest-lived, most reliable, and lowest-cost space launch vehicle. Delta began as Thor, a crash December 1955 program to produce an intermediate range ballistic missile using existing components, which flew thirteen months after go-ahead. Fifteen months after that, a space launch version flew, using an existing upper stage. The addition of solid rocket boosters allowed the Thor core and Able/Delta upper stages to be stretched. Costs were kept down by using first and second-stage rocket engines surplus to the Apollo program in the 1970's. Continuous introduction of new 'existing' technology over the years resulted in an incredible evolution - the payload into a geosynchronous transfer orbit increasing from 68 kg in 1962 to 3810 kg by 2002. Delta survived innumerable attempts to kill the program and replace it with 'more rationale' alternatives. By 2008 nearly 1,000 boosters had flown over a fifty-year career, and cancellation was again announced. More...
  • Thor Delta American orbital launch vehicle. Commercial name for the military's Thor-Delta. The name of the Delta second stage eventually was applied to subsequent commercial follow-ons. More...

Associated Manufacturers and Agencies
  • NASA American agency overseeing development of rockets and spacecraft. National Aeronautics and Space Administration, USA, USA. More...
  • NASA Langley American agency overseeing development of rockets and spacecraft. Langley, USA. More...
  • Grumman American manufacturer of rockets and spacecraft. Grumman, Great River, NY, USA. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • Bramscher, Robert G, "A Survey of Launch Vehicle Failures", Spaceflight, 1980, Volume 22, page 351.
  • NASA Report, Development of the Fabrication and Packaging Techniques for the Echo II Satellite, Web Address when accessed: here.
  • NASA Report, Analysis of US - USSR Communications experiments conducted between Jodrell Bank Observatory /UK/ and Zimenki Observatory /USSR/ via the Echo II satellite, Web Address when accessed: here.
  • NASA Report, Project Ultra-Echo Final report, Web Address when accessed: here.
  • NASA Report, Experimental and Theoretical Evaluation of a Passive Communications Satellite Echo II , Web Address when accessed: here.
  • NASA Report, Postlaunch Structural Analysis of Echo II Satellite, Web Address when accessed: here.
  • NASA Report, Mechanical Properties of Echo II Laminate, Web Address when accessed: here.
  • NASA Report, Mechanical and Physical Properties of the Echo II Metal-Polymer Laminate, Web Address when accessed: here.
  • NASA Report, Project Echo: Satellite-Tracking Radar, Web Address when accessed: here.
  • NASA Report, Project Echo: System Calculations, Web Address when accessed: here.
  • NASA Report, Project Echo: Boresight Cameras for Recording Antenna Pointing Accuracy, Web Address when accessed: here.
  • NASA Report, Project Echo: Antenna Steering System, Web Address when accessed: here.
  • NASA Report, Project Echo: Receiving System, Web Address when accessed: here.
  • NASA Report, A Comparison of Theory and Observation of the Echo I Satellite, Web Address when accessed: here.
  • NASA Report, Flight Shock & Vibration Data of Echo Satellite Vertical Tests , Web Address when accessed: here.
  • NASA Report, Buckling of the Echo-A-12 Passive Communications Satellite, Web Address when accessed: here.
  • NASA Report, Strain measurements conducted on a full scale Echo II passive communications satellite balloon, Web Address when accessed: here.
  • NASA Report, The Echo I Inflation System, Web Address when accessed: here.
  • NASA Report, Echo II Data Reduction and Analysis Six Months Summary Report, Web Address when accessed: here.

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC17A Delta launch complex. Part of a dual launch pad complex built for the Thor ballistic missile program in 1956. Pad 17A supported Thor, Delta, and Delta II launches into the 21st Century. More...

Echo Chronology


1960 May 13 - . 09:16 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17A. LV Family: Delta. Launch Vehicle: Thor Delta. LV Configuration: Thor Delta 144/D1. FAILURE: Second stage attitude control failure.. Failed Stage: 2.
  • Echo 1 - . Payload: A-10. Mass: 56 kg (123 lb). Nation: USA. Agency: NASA. Class: Communications. Type: Civilian communications satellite. Spacecraft: Echo. Decay Date: 1960-05-13 . COSPAR: F600513A.

1960 August 12 - . 09:39 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC17A. LV Family: Delta. Launch Vehicle: Thor Delta. LV Configuration: Thor Delta 270/D2.
  • Echo 1 - . Payload: A-11. Mass: 76 kg (167 lb). Nation: USA. Agency: NASA. Class: Technology. Type: Communications technology satellite. Spacecraft: Echo. Decay Date: 1968-05-24 . USAF Sat Cat: 49 . COSPAR: 1960-Iota-1. Apogee: 2,157 km (1,340 mi). Perigee: 966 km (600 mi). Inclination: 47.3000 deg. Period: 117.30 min. Summary: Balloon; passively relayed TV and voice transmissions. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). .

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