Nimbus 2 (also called Nimbus-C) was a

meteorological 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 ...

. It was the second in a series of the

Nimbus program The Nimbus satellites were second-generation U.S. robotic spacecraft launched between 1964 and 1978 used for meteorology, meteorological research and development. The spacecraft were designed to serve as stabilized, Earth-oriented platforms fo ...

Launch

Nimbus 2 was launched on May 15, 1966, by a

Thor-Agena Thor-Agena was a series of orbital launch vehicles. The launch vehicles used the Douglas Aircraft Company, Douglas-built Thor (rocket family), Thor first Multistage rocket, stage and the Lockheed Corporation, Lockheed-built RM-81 Agena, Agena ...

rocket 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 ...

, United States. The spacecraft functioned nominally until January 17, 1969. The satellite orbited the

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 ...

once every 1 hour and 48 minutes, at an inclination of 100°. Its

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

was and its

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

was .

Mission

The second in a series of second-generation

meteorological Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture ...

research and development satellites, Nimbus 2 was designed to serve as a stabilized, Earth-oriented platform for the testing of advanced meteorological sensor systems and the collecting of meteorological data. The polar-orbiting spacecraft consisted of three major elements: (1) a

torus In geometry, a torus (: tori or toruses) is a surface of revolution generated by revolving a circle in three-dimensional space one full revolution about an axis that is coplanarity, coplanar with the circle. The main types of toruses inclu ...

-shaped sensory ring, (2) solar paddles, and (3) the control system housing. The solar paddles and control system housing were connected to the sensory ring by a

truss A truss is an assembly of ''members'' such as Beam (structure), beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so ...

structure, giving the satellite the appearance of an ocean

buoy A buoy (; ) is a buoyancy, floating device that can have many purposes. It can be anchored (stationary) or allowed to drift with ocean currents. History The ultimate origin of buoys is unknown, but by 1295 a seaman's manual referred to navig ...

. Nimbus 2 was nearly tall, in diameter at the base, and about across with solar paddles extended. The sensory ring, which formed the satellite base, housed the electronics equipment and battery modules. The lower surface of the sensory ring provided mounting space for sensors and

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', 'far off', an ...

antennas. An H-frame structure mounted within the center of the torus provided support for the larger experiments and tape recorders. Mounted on the control system housing, which was located on top of the spacecraft, were

Sun sensor A Sun sensor is a navigational instrument used by spacecraft to detect the position of the Sun. Sun sensors are used for Spacecraft attitude control, attitude control, solar array pointing, gyroscope, gyro updating, and safe mode (spacecraft), fai ...

s, horizon scanners, gas nozzles for

attitude control Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle or satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, ...

, and a command antenna. Use of a stabilization and control system allowed the spacecraft's orientation to be controlled to within plus or minus 1° for all three axes (pitch, roll, yaw). The spacecraft carried: * Advanced Vidicon Camera System (AVCS): instrument for recording and storing remote

cloud cover Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds on average when observed from a particular location. Okta is the usual unit for measurement of the cloud cover. The cloud c ...

pictures * Automatic Picture Transmission (APT): instrument for providing real-time cloud cover pictures * High and Medium Resolution Infrared Radiometers (HRIR/MRIR): for measuring the intensity and distribution of

electromagnetic radiation In physics, electromagnetic radiation (EMR) is a self-propagating wave of the electromagnetic field that carries momentum and radiant energy through space. It encompasses a broad spectrum, classified by frequency or its inverse, wavelength ...

emitted by and reflected from the Earth and its

atmosphere An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...

The Nimbus 2 and experiments performed normally after launch until July 26, 1966, when the spacecraft tape recorder failed. Its function was taken over by the HRIR tape recorder until November 15, 1966, when it also failed. Some real-time data were collected until January 17, 1969, when the spacecraft mission was terminated owing to deterioration of the horizon scanner used for Earth reference.

References

{{satellite-stub Weather satellites of the United States Spacecraft launched in 1966