![]() Echo 1 sits fully inflated at a Navy hangar in Weeksville, North Carolina. | |
Names | ECHO 1 NASA A-11 |
---|---|
Mission type | Communications |
Operator | NASA |
Harvard designation | 1960 Alpha 11 |
COSPAR ID | 1960-009A |
SATCAT no. | 00049 |
Mission duration | 7.75 years (achieved) |
Spacecraft properties | |
Bus | ECHO |
Manufacturer | Bell Labs |
Launch mass | 180 kg (400 lb) |
Dimensions | 30.48 m (100.0 ft) diameter sphere when inflated |
Start of mission | |
Launch date | 12 August 1960, 03:39:43 GMT |
Rocket | Thor DM-19 Delta (Thor 270 / Delta 2) |
Launch site | Cape Canaveral, LC-17A |
Contractor | Douglas Aircraft Company |
End of mission | |
Decay date | 25 May 1968 |
Orbital parameters | |
Reference system | Geocentric orbit |
Regime | Low Earth orbit |
Perigee altitude | 1,524 km (947 mi) |
Apogee altitude | 1,684 km (1,046 mi) |
Inclination | 47.2° |
Period | 118.3 minutes |
![]() Echo 2 | |
Names | NASA A-12 |
---|---|
Mission type | Communications |
Operator | NASA |
COSPAR ID | 1964-004A |
SATCAT no. | 00740 |
Mission duration | 5.5 years (achieved) |
Spacecraft properties | |
Bus | ECHO |
Manufacturer | Bell Labs |
Dimensions | 41 m (135 ft) diameter sphere when inflated |
Start of mission | |
Launch date | 25 January 1964, 13:59:04 GMT |
Rocket | Thor-Agena B (Thor 397 / Agena 6301 / TA-2) |
Launch site | Vandenberg, LC-75-1-1 (SLC-2E) |
Contractor | Douglas Aircraft Company (Thor) Lockheed Martin (Agena) |
End of mission | |
Decay date | 7 June 1969 |
Orbital parameters | |
Reference system | Geocentric orbit |
Regime | Low Earth orbit |
Perigee altitude | 1,029 km (639 mi) |
Apogee altitude | 1,316 km (818 mi) |
Inclination | 81.5° |
Period | 108.95 minutes |
Project Echo was the first passive communications satellite experiment. Each of the two American spacecraft, launched in 1960 and 1964, were metalized balloon satellites acting as passive reflectors of microwave signals. Communication signals were transmitted from one location on Earth and bounced off the surface of the satellite to another Earth location.[1]
The first transmissions using Echo were sent from Goldstone, California, to Crawford Hill in Holmdel, New Jersey, on 12 August 1960. The last Echo satellite deorbited and burned up in the atmosphere on 7 June 1969.[2]