# USA 77

> 21809

**Wikidata**: [Q111499559](https://www.wikidata.org/wiki/Q111499559)  
**Source**: https://4ort.xyz/entity/usa-77

## Summary
USA 77 is an artificial satellite with the designation 21809. It is a human-made object that has been placed into orbit around Earth.

## Key Facts
- USA 77 is classified as an artificial satellite
- It has the designation number 21809
- It is a human-made object placed in Earth orbit
- It has 142 sitelinks in Wikidata
- It is represented in Wolfram Language as Entity["Satellite", "21809"]

## FAQs
### Q: What is USA 77?
A: USA 77 is an artificial satellite with the designation 21809. It is a human-made object that has been placed into orbit around Earth.

### Q: How is USA 77 classified?
A: USA 77 is classified as an artificial satellite, which is a human-made object put into an orbit.

### Q: What is the designation number of USA 77?
A: The designation number of USA 77 is 21809.

## Why It Matters
USA 77 represents the ongoing human endeavor to place artificial objects in Earth's orbit for various purposes. As an artificial satellite, it contributes to the growing network of human-made objects circling our planet, which serves critical functions in communications, navigation, Earth observation, and scientific research. The existence of USA 77 demonstrates the technological capabilities of space-faring nations and organizations to design, build, and launch complex systems that can operate in the harsh environment of space. Its presence in orbit is part of the broader infrastructure that enables modern global connectivity and data collection.

## Notable For
- Being designated as satellite number 21809 in the USA satellite series
- Having 142 sitelinks in Wikidata, indicating significant documentation and interest
- Being represented in Wolfram Language computational systems
- Contributing to the artificial satellite population in Earth orbit
- Demonstrating continued satellite deployment capabilities

## Body
### Classification and Identification
USA 77 is classified as an artificial satellite, which is defined as a human-made object placed into orbit around Earth or other celestial bodies. The satellite carries the designation number 21809, which serves as its unique identifier within satellite cataloging systems.

### Technical Representation
The satellite is represented in computational systems as Entity["Satellite", "21809"] in Wolfram Language, indicating its inclusion in formal satellite databases and computational knowledge systems. This representation allows for integration with various analytical and simulation tools.

### Documentation and Interest
With 142 sitelinks in Wikidata, USA 77 has generated significant documentation and interest across multiple knowledge platforms. This level of documentation suggests that the satellite has been subject to various studies, tracking efforts, and information gathering activities.

### Role in Space Infrastructure
As an artificial satellite, USA 77 contributes to the growing population of human-made objects in Earth orbit. These satellites form critical infrastructure for modern technological systems, including communications networks, navigation systems, and Earth observation capabilities.