# SBS 4

> American geostationary communications satellite

**Wikidata**: [Q14771278](https://www.wikidata.org/wiki/Q14771278)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/SBS_4)  
**Source**: https://4ort.xyz/entity/sbs-4

## Summary
SBS 4 is an American geostationary communications satellite launched in 1984 as part of the HGS series. It was operated by Satellite Business Systems and powered by a spacecraft solar array, providing telecommunications services from geostationary orbit.

## Key Facts
- **Class**: Communications satellite and geostationary satellite
- **Operator**: Satellite Business Systems
- **Launch Date**: August 30, 1984, at 12:41:50 UTC
- **Launch Vehicle**: Space Shuttle *Discovery* (STS-41-D mission)
- **Launch Site**: Kennedy Space Center Launch Complex 39A
- **Manufacturer**: Hughes Aircraft Company
- **Spacecraft Bus**: Boeing 376
- **Power Source**: Spacecraft solar array
- **Launch Mass**: 1,117 kg (launch weight)
- **Service Mass**: 540 kg (service entry)
- **Orbit**: Geostationary orbit
- **Part of Series**: HGS (High Capacity Satellite) series
- **Aliases**: Satellite Business Systems 4, SBS4, SBS-D, HGS-5
- **Country of Origin**: United States

## FAQs
### Q: What was the purpose of SBS 4?
A: SBS 4 was a geostationary communications satellite designed to provide telecommunications services, part of the HGS series operated by Satellite Business Systems.

### Q: How was SBS 4 launched?
A: SBS 4 was launched on August 30, 1984, aboard the Space Shuttle *Discovery* during the STS-41-D mission from Kennedy Space Center Launch Complex 39A.

### Q: What was the mass of SBS 4 at launch?
A: SBS 4 had a launch mass of 1,117 kg, reducing to 540 kg upon reaching service entry.

### Q: Who operated SBS 4?
A: SBS 4 was operated by Satellite Business Systems, a U.S.-based company.

### Q: What type of orbit did SBS 4 use?
A: SBS 4 was placed in a geostationary orbit, allowing it to maintain a fixed position relative to Earth's surface.

## Why It Matters
SBS 4 was part of the HGS series, which aimed to provide high-capacity communications services. As a geostationary satellite, it offered reliable telecommunications coverage, supporting applications such as television broadcasting, data transmission, and other commercial services. Launched during the Space Shuttle era, its deployment demonstrated the capabilities of reusable launch systems for satellite deployment. The satellite's solar-powered design ensured long-term operational efficiency. While specific mission details are limited, SBS 4 contributed to the expansion of global communications infrastructure in the 1980s.

## Notable For
- **First in Series**: One of the first satellites in the HGS series, designed for high-capacity telecommunications.
- **Shuttle Deployment**: Launched via the Space Shuttle, showcasing the early use of reusable spacecraft for satellite deployment.
- **Geostationary Positioning**: Maintained a fixed position in geostationary orbit for continuous service coverage.
- **Solar-Powered**: Utilized a spacecraft solar array for energy, ensuring long-term operational reliability.
- **Commercial Operator**: Operated by Satellite Business Systems, a key player in early commercial satellite communications.

## Body
### Overview
SBS 4 was a communications satellite developed by Hughes Aircraft Company and operated by Satellite Business Systems. It was part of the HGS series, which focused on providing high-capacity telecommunications services.

### Launch and Deployment
- **Launch Date**: August 30, 1984, at 12:41:50 UTC.
- **Launch Vehicle**: Space Shuttle *Discovery* (STS-41-D mission).
- **Launch Site**: Kennedy Space Center Launch Complex 39A.
- **Spacecraft Bus**: Boeing 376.

### Technical Specifications
- **Mass**:
  - Launch weight: 1,117 kg.
  - Service entry: 540 kg.
- **Power Source**: Spacecraft solar array.
- **Orbit**: Geostationary orbit.

### Operational Details
- **Operator**: Satellite Business Systems.
- **Country of Origin**: United States.
- **Significant Event**: Launched as part of the STS-41-D mission, marking an early use of the Space Shuttle for satellite deployment.

### Classification and Series
- **Instance of**: Communications satellite and geostationary satellite.
- **Part of Series**: HGS (High Capacity Satellite) series.

### Identifiers
- **SCN**: 15235.
- **COSPAR ID**: 1984-093B.
- **NSSDCA ID**: 1984-093B.

### Aliases
- Satellite Business Systems 4.
- SBS4.
- SBS-D.
- HGS-5.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/sbs-1.htm)
2. Jonathan's Space Report