ITOS-B was a

weather satellite A weather satellite or meteorological satellite is a type of Earth observation satellite that is primarily used to monitor the weather and climate of the Earth. Satellites are mainly of two types: polar orbiting (covering the entire Earth asyn ...

operated by the

National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (NOAA ) is an American scientific and regulatory agency charged with Weather forecasting, forecasting weather, monitoring oceanic and atmospheric conditions, Hydrography, charting the seas, ...

(NOAA). It was part of a series of satellites called ITOS, or improved

TIROS Television InfraRed Observation Satellite (TIROS) 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, enabling sc ...

. ITOS-B was launched on October 21, 1971 from

Vandenberg Air Force Base Vandenberg may refer to: * Vandenberg (surname), including a list of people with the name * USNS ''General Hoyt S. Vandenberg'' (T-AGM-10), transport ship in the United States Navy, sank as an artificial reef in Key West, Florida * Vandenberg S ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

, on a

Delta N6 Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...

(sn. 572/D-86) rocket. It failed to achieve a successful Earth orbit. A malfunction in the

second stage Second stage may refer to Spaceflight * The second stage of a multistage rocket **Delta Cryogenic Second Stage ** Falcon 1 second-stage ** S-II second stage ** Short nozzle second stage Other uses * Second Stage Theater, theatre company in New Yor ...

launch vehicle caused the spacecraft to reenter the Earth's atmosphere about 1 hour after lift-off.

Description

ITOS-B was designed to provide improved operational

infrared Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those ...

and visual observations of earth cloud cover for use in weather analysis and forecasting. Secondary objectives included obtaining both solar

proton A proton is a stable subatomic particle, symbol , Hydron (chemistry), H+, or 1H+ with a positive electric charge of +1 ''e'' (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an e ...

and global heat balance data on a daily basis. To accomplish these tasks, the Sun-synchronous spacecraft carried four cameras - 2 television cameras for automatic picture transmissions (APT) and two advanced vidicon camera system (AVCS) cameras. It also carried a low-resolution flat plate radiometer, a solar proton monitor, and two scanning

radiometer A radiometer or roentgenometer is a device for measuring the radiant flux (power) of electromagnetic radiation. Generally, a radiometer is an infrared radiation detector or an ultraviolet detector. Microwave radiometers operate in the micro ...

s that not only could measure emitted

IR radiation Infrared (IR; sometimes called infrared light) is electromagnetic radiation (EMR) with wavelengths longer than that of visible light but shorter than microwaves. The infrared spectral band begins with the waves that are just longer than those of ...

but could also serve as a backup system for the APT and AVCS cameras. The nearly cubical spacecraft measured . The TV cameras and infrared sensors were mounted on the satellite baseplate with their optical axes directed vertically earthward. The satellite was equipped with three curved solar panels that were folded during launch and were to be deployed after orbit was achieved. Each panel measured over in length when unfolded and was covered with 3420

solar cell A solar cell, also known as a photovoltaic cell (PV cell), is an electronic device that converts the energy of light directly into electricity by means of the photovoltaic effect.

s, each by . A dynamics and attitude control system was designed to maintain desired spacecraft orientation through

gyroscopic A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining orientation and angular velocity. It is a spinning wheel or disc in which the axis of rot ...

principles incorporated into the satellite design.

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

orientation was to be maintained by taking advantage of the precession induced from a

momentum In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. ...

flywheel A flywheel is a mechanical device that uses the conservation of angular momentum to store rotational energy, a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, a ...

so that the satellite body

precession Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In o ...

rate of one revolution per orbit would provide the desired 'Earth looking' attitude. Minor adjustments in attitude and orientation could be made by means of magnetic coils and by varying the speed of the momentum flywheel.

References

1971 in spaceflight Weather satellites of the United States Spacecraft launched in 1971 Television Infrared Observation Satellites {{satellite-stub