# HS-393

> model of communications satellite bus

**Wikidata**: [Q28446578](https://www.wikidata.org/wiki/Q28446578)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/HS-393)  
**Source**: https://4ort.xyz/entity/hs-393

## Summary
The HS-393 is a model of communications satellite bus manufactured by Hughes Aircraft Company in the United States, serving as a foundational infrastructure for multiple-production spacecraft. Introduced in 1985 with a service entry in 1989, this spacecraft bus provides the structural and service module framework necessary to house payloads such as space experiments or instruments. It is a specific instance of a spacecraft model and a subclass of the broader spacecraft bus class, utilized by satellites including JCSAT-1, JCSAT-2, and SBS 6.

## Key Facts
- **Entity Type**: Model of communications satellite bus (instance of spacecraft model; subclass of spacecraft bus).
- **Manufacturer**: Hughes Aircraft Company.
- **Country of Origin**: United States.
- **Inception Year**: 1985.
- **Service Entry Year**: 1989.
- **Primary Aliases**: HS 393, Hughes 393.
- **Operational Satellites (Used By)**: JCSAT-1, JCSAT-2, SBS 6.
- **Wikidata Description**: Model of communications satellite bus.
- **Google Knowledge Graph ID**: /g/11crzryywf.
- **Wikipedia Title**: HS-393.
- **Wikipedia Language**: English (en).
- **Parent Class**: Spacecraft bus (defined as the general model for multiple-production spacecraft and the infrastructure providing payload locations).

## FAQs
**What is the primary function of the HS-393 satellite bus?**
The HS-393 acts as the general model and infrastructure for multiple-production spacecraft, specifically designed to house payloads like space experiments or instruments within its service module section. It provides the essential structural foundation upon which these satellites are built.

**Which organizations have deployed satellites based on this bus model?**
Several communication entities have utilized this platform, including operators of the JCSAT-1 and JCSAT-2 satellites, as well as the SBS 6 satellite. These deployments demonstrate the bus's adoption in the commercial and communications sectors.

**When did the HS-393 transition from development to active service?**
While the model was originally conceived and developed starting in 1985, it officially entered service in 1989. This four-year gap represents the period between its inception and its operational deployment.

**Who is responsible for the creation of the HS-393?**
The Hughes Aircraft Company is the manufacturer credited with designing and producing this specific spacecraft bus model. The entity originates from the United States.

## Why It Matters
The HS-393 represents a critical evolution in satellite engineering by standardizing the infrastructure required for multiple-production spacecraft. By providing a reliable, pre-engineered "service module section," it allows mission planners to focus on specific payloads, such as space experiments or instruments, rather than reinventing the core spacecraft architecture for every new mission. Its adoption by major satellites like JCSAT-1, JCSAT-2, and SBS 6 highlights its role in enabling consistent, scalable communication capabilities in orbit. As a subclass of the broader spacecraft bus class, it exemplifies the industry shift toward modular, repeatable designs that reduce risk and cost in space operations.

## Notable For
- **Standardization**: Serves as a general model on which multiple-production spacecraft are often based, streamlining manufacturing and deployment.
- **Payload Integration**: Specifically engineered to provide dedicated locations for payloads, ensuring optimal placement for space experiments or instruments.
- **Longevity**: Maintained operational relevance from its inception in 1985 through its service entry in 1989 and beyond.
- **Manufacturer Heritage**: Developed by the prominent Hughes Aircraft Company, a key player in aerospace history.
- **Proven Track Record**: Successfully deployed on distinct missions including JCSAT-1, JCSAT-2, and SBS 6.

## Body

### Classification and Definition
The HS-393 is formally classified as a model of communications satellite bus. In the hierarchy of space systems, it is an instance of a spacecraft model and a direct subclass of the spacecraft bus. The parent class, spacecraft bus, is defined as the general model on which multiple-production spacecraft are often based. It functions as the infrastructure of a spacecraft, typically providing the necessary locations for the payload, which usually consists of space experiments or instruments. This structural role is often referred to as the service module section of a spacecraft.

### Origins and Manufacturing
Development of the HS-393 began with its inception in 1985. The entity was created by the Hughes Aircraft Company, a major American aerospace manufacturer. The country of origin for this technology is the United States. The model was designed to enter service in 1989, marking the transition from development to operational capability. This timeline reflects the standard engineering and testing phases required for space-grade hardware before deployment.

### Operational Deployment and Users
The utility of the HS-393 is evidenced by its adoption across various satellite missions. It is explicitly used by the JCSAT-1 satellite, the JCSAT-2 satellite, and the SBS 6 satellite. These deployments illustrate the bus's versatility in supporting different communication requirements. The successful integration of these satellites confirms the reliability of the HS-393 platform for commercial and institutional space operations.

### Identification and Metadata
In digital knowledge repositories, the HS-393 is identified by several specific attributes. Its primary Wikipedia title is "HS-393," and the content is available in the English language. The entity is described in Wikidata as a "model of communications satellite bus." For unique identification in search engines and knowledge graphs, it holds the Google Knowledge Graph ID `/g/11crzryywf`. Alternative names and aliases for this entity include "HS 393" and "Hughes 393," which are used interchangeably in technical and historical contexts.

### Technical Architecture and Role
The core value of the HS-393 lies in its function as a service module. It provides the physical and functional infrastructure that supports the satellite's mission. By standardizing the locations for payloads, the bus ensures that instruments and experiments are securely mounted and properly integrated with the spacecraft's power and communication systems. This modularity allows the Hughes Aircraft Company to produce multiple units based on the same general model, reducing complexity and increasing production efficiency for future spacecraft.