ESSA 3 [NASA]
The ESSA series was the second generation of US meterological satellites after the TIROS (Television & Infra-Red Observation Satellite) series. They were also called OT (Operational TIROS), TOS (TIROS Operational Satellite).
This desiign was a spin-stabilized operational meteorological spacecraft designed to take and record daytime cloudcover pictures on a global basis for subsequent playback to a ground acquisition station. The satellite had essentially the same configuration as that of the TIROS series, i.e., an 18-sided right prism, 107 cm across opposite corners and 56 cm high, with a reinforced baseplate carrying most of the subsystems and a cover assembly (hat). Electrical power was provided by approximately 10,000 1- by 2-cm solar cells that were mounted on the cover assembly and by 21 nickel-cadmium batteries.
Two redundant wide-angle cameras were mounted on opposite sides of the spacecraft and canted 75 deg from the spacecraft spin axis. A pair of crossed-dipole command and receiving antennas projected out and down from the baseplate. A monopole telemetry and tracking antenna extended up from the top of the cover assembly.
There were differences in the imaging system acorss the series:
The satellites were placed in a cartwheel orbital mode, with its spin axis maintained normal to the orbital plane. The satellite spin rate and attitude were determined primarily by a Magnetic Attitude Spin Coil (MASC). The MASC was a current-carrying coil mounted in the cover assembly. The magnetic field induced by the current interacted with the earth's magnetic field to provide the necessary torque to maintain a desired spin rate of 9.225 rpm. Five small solid-fuel thrusters mounted around the baseplate provided a secondard means of controlling the spacecraft spin rate.
Nation: | USA |
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Type / Application: | Meteorology |
Operator: | ESSA |
Contractors: | RCA |
Equipment: | 2 × AVCS (#T9, 1, 3, 5, 7, 9); 2 × APT (#2, 4, 6, 8); FPR (#3, 5, 7, 9) |
Configuration: | |
Propulsion: | ? |
Power: | Solar cells, batteries |
Lifetime: | |
Mass: | 138 kg (#T9, 1); 286 kg (#2, 4) 145 kg (#3, 5, 7, 9), 298 kg (#6, 8) |
Orbit: | SSO |
Satellite | COSPAR | Date | LS | Launch Vehicle | Remarks | |
---|---|---|---|---|---|---|
TIROS 9 (A 54) | 1965-004A | 22.01.1965 | CC LC-17A | Delta-C | ||
ESSA 1 (OT 3, TIROS 11) | 1966-008A | 03.02.1966 | CC LC-17A | Delta-C | ||
ESSA 2 (OT 2, TIROS 12) | 1966-016A | 28.02.1966 | CC LC-17B | Delta-E | ||
ESSA 3 (TOS 1, TIROS 13) | 1966-087A | 02.10.1966 | Va SLC-2E | Delta-E | ||
ESSA 4 (TOS 2, TIROS 14) | 1967-006A | 26.01.1967 | Va SLC-2E | Delta-E | ||
ESSA 5 (TOS 3, TIROS 15) | 1967-036A | 20.04.1967 | Va SLC-2E | Delta-E | ||
ESSA 6 (TOS 4, TIROS 16) | 1967-114A | 10.11.1967 | Va SLC-2E | Delta-E1 | ||
ESSA 7 (TOS 5, TIROS 17) | 1968-069A | 16.08.1968 | Va SLC-2E | Delta-N | ||
ESSA 8 (TOS 6, TIROS 18) | 1968-114A | 15.12.1968 | Va SLC-2E | Delta-N | ||
ESSA 9 (TOS 7, TIROS 19) | 1969-016A | 26.02.1969 | CC LC-17B | Delta-E1 | ||
ESSA 10 (TOS H) | - | cancelled |