ESSA-1 (or OT-3) was a spin-stabilized operational meteorological satellite. Its name was derived from that of its oversight agency, the

Environmental Science Services Administration The Environmental Science Services Administration (ESSA) was a United States Federal executive agency created in 1965 as part of a reorganization of the United States Department of Commerce. Its mission was to unify and oversee the meteorologica ...

(ESSA).

Launch

ESSA-1 was launched on February 3, 1966, at 07:41 UTC. It was launched atop a

Delta Delta commonly refers to: * Delta (letter) (Δ or δ), a letter of the Greek alphabet * River delta, at a river mouth * D ( NATO phonetic alphabet: "Delta") * Delta Air Lines, US * Delta variant of SARS-CoV-2 that causes COVID-19 Delta may also ...

rocket from Cape Canaveral,

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

. The spacecraft had a mass of at the time of launch. ESSA-1 had an inclination of 97.91°, and an orbited the earth once every 100 minutes. Its

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

was and its

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

was . ESSA-1 had a similar design to that of the

TIROS TIROS, or Television InfraRed Observation Satellite, is a series of early weather satellites launched by the United States, beginning with TIROS-1 in 1960. TIROS was the first satellite that was capable of remote sensing of the Earth, enabli ...

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...

series. It was an 18-sided right prism, measuring across opposite corners and . It had a reinforced

baseplate In photography, a tripod is a portable device used to support, stabilize and elevate a camera, a flash unit, or other videographic or observational/measuring equipment. All photographic tripods have three legs and a mounting head to couple wi ...

, which carried most of the subsystems and a cover assembly (hat). ESSA-1 had approximately 10,000 1-cm by 2-cm

solar cell A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.

s, which charged 21 nickel–cadmium batteries. ESSA-1 was designed to take pictures of daytime cloud cover, record them, and transmit them when it was in range of a ground acquisition station. 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 coil interacted with that of the Earth's magnetic field, and provided the necessary torque to maintain a desired spin rate of 9.225 revolutions per minute (rpm). Five small solid-fuel thrusters mounted on the baseplate provided a secondary means of controlling the spin rate. ESSA-1 operated normally until October 6, 1966, when the camera system failed. The

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...

was fully deactivated on May 8, 1967, after being left on for an additional period of time for engineering purposes.

References

External links

* * * * * * * * * {{DEFAULTSORT:Essa-1 Spacecraft launched in 1966 Weather satellites of the United States