# Estrela Do Sul > 28137 **Wikidata**: [Q111497459](https://www.wikidata.org/wiki/Q111497459) **Source**: https://4ort.xyz/entity/estrela-do-sul-q111497459 ## Summary Estrela Do Sul is an artificial satellite identified by the numerical designation 28137. It is classified as a human-made object placed into orbit around a celestial body, distinct from natural satellites. As an instance of an artificial satellite, it operates within the broader infrastructure of space technology used for communication, navigation, and research. ## Key Facts - **Entity Name**: Estrela Do Sul - **Numerical Designation**: 28137 - **Classification**: Instance of an **Artificial Satellite** - **Wolfram Language Entity Code**: `Entity["Satellite", "28137"]` - **Primary Definition**: A human-made object placed into orbit around a celestial body (typically Earth). - **Parent Class**: Spacecraft - **Orbital Mechanics**: Maintains orbit through a balance of gravitational pull and forward velocity (centrifugal force). - **Operational Context**: Shares the space environment with other variants including passive satellites, tethered satellites, and miniaturized femtosatellites. ## FAQs ### Q: What specific type of object is Estrela Do Sul? A: Estrela Do Sul is an artificial satellite, a specific subclass of spacecraft engineered to operate in space and orbit a celestial body. ### Q: How is an artificial satellite like Estrela Do Sul defined? A: It is defined as a human-made object placed into orbit. Unlike natural satellites (like moons), these are launched by rockets—such as the historic Sputnik 1 in 1957—and serve functions like communication, navigation, or scientific observation. ### Q: What are the orbital characteristics of artificial satellites? A: Satellites can occupy various orbits, including geostationary (fixed over a point on Earth), low Earth orbit (LEO), or heliocentric orbits (around the Sun). They stay aloft by balancing gravitational pull with their forward velocity. ### Q: What distinguishes an artificial satellite from a general spacecraft? A: While "spacecraft" is a broad category covering probes, rovers, and crewed vehicles, an artificial satellite is specifically designed to orbit a celestial body. ## Why It Matters Estrela Do Sul represents a node in the vast network of artificial satellites that serve as the backbone of modern infrastructure. Artificial satellites are indispensable for global communication, enabling television, internet, and telephony. They power the Global Positioning System (GPS) used for navigation and are critical for real-time weather monitoring and military surveillance. The deployment of such objects, a practice begun with Sputnik 1 in 1957, fundamentally revolutionized how humanity conducts scientific research and manages global security. However, the proliferation of such objects creates challenges regarding space debris and orbital congestion, necessitating ongoing management and sustainability solutions. ## Notable For - **Classification as an Artificial Satellite**: Belongs to the class of human-made objects that initiated the Space Age. - **Technological Lineage**: Shares a category with Sputnik 1 (1957), the first human-made object in space. - **Infrastructure Role**: Part of the system enabling global communication, navigation, and scientific observation. - **Wolfram Language Recognition**: Coded as `Entity["Satellite", "28137"]` in computational knowledge bases. ## Body ### Definition and Identification Estrela Do Sul is identified in knowledge bases as an **artificial satellite** with the specific numeric designation **28137**. In the Wolfram Language, it is represented by the entity code `Entity["Satellite", "28137"]`. As an **artificial satellite**, it is a human-made object placed into orbit around a celestial body, typically the Earth. It falls under the broader classification of **spacecraft**, specifically engineered to operate in the space environment. This distinguishes it from natural satellites and other spacecraft types like probes or crewed vehicles. ### Operational Mechanics To remain in space, satellites like Estrela Do Sul utilize a balance of physical forces. They maintain orbit through the interplay of **gravitational pull** and their own **forward velocity**, which creates centrifugal force to counteract gravity. ### Context of the Artificial Satellite Class The class of "artificial satellite" includes a diverse range of technologies and historical milestones that provide context for Estrela Do Sul's classification: #### Historical Milestones - **1957 (Sputnik 1)**: The Soviet Union launched the first artificial satellite on October 4, 1957, marking the beginning of the space age. - **1960 (Project Echo)**: The first passive communications satellite, which reflected radio signals. - **1966 (PAGEOS)**: A NASA passive geodetic satellite used for Earth observation and research. #### Variants and Types The artificial satellite class is categorized by function and design: - **Passive Satellites**: Objects like Project Echo that reflect signals rather than transmitting them. - **Tethered Satellites**: Systems consisting of two parts connected by a cable. - **Miniaturized Satellites**: Small-scale units including femtosatellites and picosatellites (weighing less than 1 kg). - **Specialized Satellites**: Advanced concepts like orbital power plants designed to capture and wirelessly transmit solar energy. #### Orbital Types Satellites operate in distinct orbital regimes: - **Geostationary**: Remaining fixed over a specific point on Earth. - **Low Earth Orbit (LEO)**: Used extensively for communication and Earth observation. - **Heliocentric**: Satellites that orbit the Sun rather than Earth. ### Applications and Impact The artificial satellite class serves as the foundation for critical modern utilities: - **Communication**: Backbone for television, internet, and telephony. - **Navigation**: Enables GPS and global positioning systems. - **Scientific Research**: Facilitates the study of Earth’s atmosphere, climate, and deep space. - **Military**: Provides secure communications and surveillance capabilities (e.g., Syracuse 4, Gonets-M). ### Challenges and Sustainability The operation of artificial satellites is increasingly complicated by **space debris** and **orbital congestion**. Thousands of defunct satellites and fragments pose collision risks. To address this, **space debris removal satellites** are currently being developed to manage orbital clutter and ensure the sustainability of the space environment.