# OrbView-2

> American Earth observation satellite

**Wikidata**: [Q116468885](https://www.wikidata.org/wiki/Q116468885)  
**Source**: https://4ort.xyz/entity/orbview-2

## Summary
OrbView-2, also known as SeaStar, is an American Earth observation satellite launched in 1997 to monitor the Earth's oceans and land surfaces. Manufactured by Orbital Sciences Corporation and operated by GeoEye, it is primarily known for carrying the SeaWiFS scientific instrument. The satellite remained operational for over 13 years until a final loss of signal in December 2010.

## Key Facts
- **Alternative Name:** SeaStar
- **Launch Date:** August 1, 1997 (20:20 UTC)
- **Manufacturer:** Orbital Sciences Corporation
- **Operator:** GeoEye
- **Scientific Instrument:** SeaWiFS (Sea-viewing Wide Field-of-view Sensor)
- **Launch Vehicle:** Pegasus (F16) air-launched rocket
- **Spacecraft Bus:** Star Bus
- **Launch Weight:** 309 kilograms
- **Power System:** Four spacecraft solar array panels providing 170 units of power
- **Operational End Date:** December 11, 2010 (Loss of signal)

## FAQs
### Q: What was the primary purpose of OrbView-2?
A: OrbView-2 was an Earth observation satellite designed to collect global biological data. It used its primary instrument, SeaWiFS, to monitor ocean color and land vegetation, providing data essential for studying the Earth's biosphere.

### Q: How was OrbView-2 launched into space?
A: The satellite was deployed using an air-launch method. It was carried by a Pegasus (F16) rocket attached to the "Stargazer" mother ship, which took off from Vandenberg Space Force Base before releasing the rocket to orbit.

### Q: Who owned and operated the OrbView-2 satellite?
A: The satellite was operated by GeoEye. It was originally manufactured by the Orbital Sciences Corporation using their proprietary Star Bus spacecraft platform.

### Q: When did OrbView-2 stop working?
A: OrbView-2 ceased operations following a "loss of signal" event on December 11, 2010. This concluded a mission that lasted more than 13 years after its initial launch in 1997.

## Why It Matters
OrbView-2 played a critical role in environmental science by providing a continuous, long-term record of the Earth's biological activity. Through its SeaWiFS instrument, it allowed researchers to observe changes in ocean chlorophyll levels and marine phytoplankton, which are vital indicators of the health of the global ecosystem and the carbon cycle. 

The mission was also a significant technical achievement for commercial space operations. It demonstrated the reliability of the Star Bus platform and the Pegasus air-launch system, which allowed for flexible deployment of satellites without the need for traditional vertical launch pads. By operating from 1997 to 2010, it provided a decade-plus dataset that remains a benchmark for Earth observation and oceanographic research.

## Notable For
- **SeaWiFS Instrument:** It served as the orbital platform for the Sea-viewing Wide Field-of-view Sensor, a specialized tool for monitoring ocean color.
- **Air-Launch Deployment:** It was successfully placed into orbit via a Pegasus rocket released from the "Stargazer" mother ship.
- **Extended Mission Life:** The satellite maintained operations for over 13 years, significantly contributing to long-term climate and biological studies before its signal was lost in 2010.
- **Star Bus Platform:** It was a prominent application of the Orbital Sciences Corporation's Star Bus spacecraft architecture.

## Body

### Technical Specifications
OrbView-2 is a 309 kg Earth observation satellite built by the Orbital Sciences Corporation. It utilized the Star Bus spacecraft bus as its primary structure. The satellite's power was generated by a spacecraft solar array consisting of four panels, which produced approximately 170 units of power. It is cataloged under SCN 24883 and COSPAR ID 1997-037A.

### Launch and Deployment
The satellite was launched on August 1, 1997, at 20:20. The launch was conducted at Vandenberg Space Force Base using a Pegasus (F16) rocket. This mission utilized a unique air-launch configuration where the "Stargazer" mother ship carried the Pegasus rocket to a high altitude before release, serving as the primary start point for the orbital ascent.

### Scientific Mission and Payload
The primary mission of OrbView-2 was the collection of Earth observation data, specifically focusing on the biological properties of the oceans and land. To achieve this, it carried the SeaWiFS (Sea-viewing Wide Field-of-view Sensor). The data gathered by this instrument was used by the scientific community to monitor global environmental changes. The satellite was managed and operated by GeoEye throughout its functional life.

### Mission Conclusion
The operational phase of OrbView-2 ended on December 11, 2010. On this date, the satellite experienced a "loss of signal," terminating its ability to transmit data back to Earth. At the time of its decommissioning, it had completed over 13 years of service in orbit.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/orbview-2.htm)
2. Jonathan's Space Report
3. [Source](https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1997-037A)