Editing Nimbus 2

{{Short description|Former U.S. meteorological satellite}}

| image_alt =

| image_caption = Design of Nimbus 2

| launch_mass = {{convert|413.70|kg}}<ref name="nssdc">{{cite web|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1966-040A|title=Nimbus 2|work=National Space Science Data Center Master Catalog|publisher=NASA Goddard Space Flight Center|access-date=June 5, 2018}} {{PD-notice}}</ref>

| launch_date = {{start-date|May 15, 1966, 07:55:34|timezone=yes}}&nbsp;UTC<ref name="launchlog">{{cite web|url=https://planet4589.org/space/gcat/data/derived/launchlog.html |title=GCAT orbital launch log |first=Jonathan C. |last=McDowell |author-link=Jonathan McDowell |work=Jonathan's Space Page |access-date=November 7, 2023}}</ref>

'''Nimbus 2''' (also called '''Nimbus-C''') was a [[meteorological satellite]]. It was the second in a series of the [[Nimbus program]].

[[File:Thor SLV-2A Agena B with Nimbus 2 (May 15, 1966) 1.JPG|thumb|left|upright=0.65|Launch of Nimbus 2]]

'''Nimbus 2''' was launched on May 15, 1966, by a [[Thor-Agena]] rocket from [[Vandenberg Air Force Base]], [[California]], United States. The spacecraft functioned nominally until January 17, 1969. The satellite orbited the [[Earth]] once every 1&nbsp;hour and 48&nbsp;minutes, at an inclination of 100°. Its [[perigee]] was {{convert|1,103|km|mi|sp=us}} and its [[apogee]] was {{convert|1,179|km|mi|sp=us}}.<ref name="nssdc"/>

The second in a series of second-generation [[meteorological]] 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 orbit|polar-orbiting]] spacecraft consisted of three major elements: (1) a [[torus]]-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]] structure, giving the satellite the appearance of an ocean [[buoy]].

Nimbus 2 was nearly {{convert|3.7|m|ft}} tall, {{convert|1.5|m|ft}} in diameter at the base, and about {{convert|3|m|ft}} across with solar paddles extended. The sensory ring, which formed the satellite base, housed the electronics equipment and [[battery (electricity)|battery]] modules. The lower surface of the sensory ring provided mounting space for sensors and [[telemetry]] [[antenna (radio)|antenna]]s. 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]]s, horizon scanners, gas nozzles for [[attitude control]], 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]] 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]] emitted by and reflected from the Earth and its [[atmosphere]]

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.<ref name="NASA nssdc">{{cite web |title=Nimbus 2|url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1966-040A |publisher=NASA Goddard Space Flight Center|access-date=June 5, 2018}}</ref>