Nimbus 4

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Nimbus 4
Nimbus rendering.jpg
Artist rendering of the Nimbus 4
Mission type Weather satellite
Operator NASA
COSPAR ID 1970-025A OOjs UI icon edit-ltr-progressive.svg
SATCAT no. 4362
Mission duration10 years and 5 months
Spacecraft properties
Manufacturer RCA Astrospace
Launch mass619.6 kilograms (1,366 lb) [1]
Dimensions3.7 m × 1.5 m × 3.0 m (12.1 ft × 4.9 ft × 9.8 ft)
Start of mission
Launch dateApril 8, 1970, 08:17:56 (1970-04-08UTC08:17:56Z) UTC [2]
Rocket Thorad-SLV2G Agena-D
Launch site Vandenberg SLC-2E
End of mission
Last contactSeptember 30, 1980 (1980-10-01)
Decay dateSeptember 30, 1980 [3]
Orbital parameters
Reference system Geocentric
Regime Low Earth
Eccentricity 0.00107 [1]
Perigee altitude 1,092 kilometers (679 mi) [1]
Apogee altitude 1,108 kilometers (688 mi) [1]
Inclination 80.114° [1]
Period 107.2 minutes [1]
Epoch April 8, 1970 [1]
  Nimbus 3
Nimbus 5  

Nimbus 4 (also called Nimbus D) was a meteorological satellite. It was the fourth in a series of the Nimbus program.

Contents

Launch

Nimbus IV launch Nimbus IV launch.jpg
Nimbus IV launch

Nimbus 4 was launched on April 8, 1970, by a Thor-Agena rocket from Vandenberg Air Force Base in Lompoc, California, United States. The spacecraft functioned nominally until September 30, 1980. The satellite orbited the Earth once every 1 hour and 47 minutes, at an inclination of 80°. Its perigee was 1,092 kilometers (679 mi) and its apogee was 1,108 kilometers (688 mi). [1]

Mission

The fourth in a series of second-generation meteorological research and development satellites, Nimbus 4 was designed to serve as a stabilized, earth-oriented platform for the testing of advanced meteorological sensor systems, and for collecting meteorological data. The polar-orbiting spacecraft consisted of three major structures: a torus-shaped sensor mount, solar paddles, and the control system housing.

The solar paddles and the control system were connected to the sensor mount by a truss structure, giving the satellite the appearance of an ocean buoy. Nimbus 4 was nearly 3.7 metres (12 ft) tall, 1.45 metres (4.8 ft) in diameter at the base, and about 3 metres (9.8 ft) across with solar paddles extended. The torus-shaped sensor mount, which formed the satellite base, housed the electronics equipment and battery modules. The lower surface of the torus ring provided mounting space for sensors and telemetry 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 on top of the spacecraft, were Sun sensors, horizon scanners, gas nozzles for attitude control, and a command antenna. Use of an advanced attitude-control subsystem permitted the spacecraft's orientation to be controlled to within plus or minus 1 degree for all three axes (pitch, roll, yaw)

Instruments

The primary experiments consisted of: [4]

The spacecraft performed well until April 14, 1971, when attitude problems started. The experiments continued to operate on a limited time basis until September 30, 1980. [1]

References

  1. 1 2 3 4 5 6 7 8 9 "Nimbus 4". National Space Science Data Center Master Catalog. NASA Goddard Space Flight Center. Retrieved June 5, 2018.PD-icon.svg This article incorporates text from this source, which is in the public domain.
  2. McDowell, Jonathan C. "GCAT orbital launch log". Jonathan's Space Page. Retrieved November 7, 2023.
  3. "NIMBUS 4". N2YO.com. Retrieved June 5, 2018.
  4. Sabatini, R. (1970) Nimbus IV User's Guide GSFC NASA-TM-X-69887