# LAGEOS-2

> second of two satellites in the LAGEOS mission

**Wikidata**: [Q84057139](https://www.wikidata.org/wiki/Q84057139)  
**Source**: https://4ort.xyz/entity/lageos-2

## Summary
LAGEOS-2 is the second of two passive geodetic satellites in the LAGEOS mission, launched in 1992 to study Earth's gravitational field and tectonic plate movements. It is a spherical, inert satellite covered in retro-reflectors, designed to reflect laser beams for precise geodetic measurements.

## Key Facts
- Launched on **October 22, 1992**, at **17:09:40 UTC** aboard the **Space Shuttle Columbia (STS-52)** from **Kennedy Space Center Launch Complex 39B**.
- Mass: **405.38 kg**, diameter: **60 cm**, made of **aluminium (shell)**, **brass (center)**, and **426 corner reflectors** (422 fused quartz, 4 germanium).
- Funded by the **Italian Space Agency** and **NASA**, manufactured by **Alenia Spazio**.
- Operates in **medium Earth orbit** as a **passive satellite**, meaning it does not generate or emit energy.
- Follows **LAGEOS-1**, the first satellite in the LAGEOS mission, and is part of the **LAGEOS program (satellite 2 of 2)**.

## FAQs
### Q: What is the purpose of LAGEOS-2?
A: LAGEOS-2 is a geodetic satellite designed to reflect laser beams for precise measurements of Earth's gravitational field, tectonic plate movements, and crustal dynamics.

### Q: When and how was LAGEOS-2 launched?
A: It was launched on **October 22, 1992**, aboard the **Space Shuttle Columbia (STS-52)** from Kennedy Space Center.

### Q: What materials is LAGEOS-2 made of?
A: The satellite has an **aluminium shell**, a **brass center**, and **426 corner reflectors** (422 made of fused quartz and 4 of germanium).

### Q: Who funded and built LAGEOS-2?
A: It was funded by the **Italian Space Agency** and **NASA**, and manufactured by **Alenia Spazio**.

### Q: How does LAGEOS-2 differ from LAGEOS-1?
A: LAGEOS-2 is the second satellite in the mission, launched 16 years after LAGEOS-1, with similar design but funded and operated in collaboration with Italy.

## Why It Matters
LAGEOS-2 plays a critical role in **geodesy**—the science of measuring Earth's shape, orientation, and gravitational field. By reflecting laser beams from ground stations, it enables ultra-precise tracking of **tectonic plate movements**, **Earth's rotation**, and **crustal deformations**. This data is essential for understanding **earthquakes**, **volcanic activity**, and **sea-level changes**. Additionally, LAGEOS-2 contributes to tests of **general relativity** and improves models of Earth's **gravity field**, aiding in satellite navigation and climate research. As a passive satellite, its long-term stability (no fuel or moving parts) ensures decades of reliable data, making it a cornerstone of modern geophysical research.

## Notable For
- **First Italian-funded geodetic satellite**, launched in collaboration with NASA.
- **High-precision laser ranging**: Equipped with **426 corner reflectors** for accurate measurements.
- **Long-term stability**: As a passive satellite, it has no moving parts or fuel, ensuring decades of operational life.
- **Contributions to gravitational physics**: Used in studies of **general relativistic effects** and Earth's gravity field.
- **Part of a dual-satellite system**: Works alongside LAGEOS-1 to provide redundant and enhanced geodetic data.

## Body
### Overview
LAGEOS-2 (Laser Geodynamics Satellite 2) is the second satellite in the **LAGEOS mission**, designed for **geodetic research**. It is a **passive satellite**, meaning it does not generate or emit energy but instead reflects laser beams from ground stations for precise measurements.

### Launch and Deployment
- **Launch Date**: October 22, 1992, at **17:09:40 UTC**.
- **Launch Vehicle**: Space Shuttle **Columbia (STS-52)**.
- **Launch Site**: **Kennedy Space Center Launch Complex 39B**.
- **Orbit**: **Medium Earth orbit**.

### Physical Characteristics
- **Mass**: 405.38 kg.
- **Diameter**: 60 cm (spherical shape).
- **Materials**:
  - **Shell**: Aluminium.
  - **Center**: Brass.
  - **Corner Reflectors**: 422 fused quartz, 4 germanium (total 426).

### Mission and Function
- **Primary Purpose**: Geodetic research, including:
  - Measuring **tectonic plate movements**.
  - Studying **Earth's gravitational field**.
  - Tracking **crustal deformations**.
- **Operational Mechanism**: Reflects laser beams from ground stations for **Satellite Laser Ranging (SLR)**.

### Funding and Manufacturing
- **Funders**: **Italian Space Agency (ASI)** and **NASA**.
- **Manufacturer**: **Alenia Spazio** (now part of Thales Alenia Space).

### Scientific Contributions
- **Geodesy**: Provides data for **Earth's shape, orientation, and gravity**.
- **General Relativity**: Used in experiments testing **Einstein's theory of relativity**.
- **Climate Research**: Helps monitor **sea-level changes** and **polar ice melt**.

### Relationship to LAGEOS-1
- **Predecessor**: LAGEOS-1 (launched in 1976).
- **Role**: LAGEOS-2 complements LAGEOS-1, providing additional data points for improved accuracy in geodetic measurements.

## Schema Markup
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  "description": "Second of two passive geodetic satellites in the LAGEOS mission, launched in 1992 to study Earth's gravitational field and tectonic movements.",
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## References

1. [Source](https://earth.gsfc.nasa.gov/geo/missions/lageos/background)
2. [Source](https://earth.gsfc.nasa.gov/geo/missions/lageos/design)
3. [Source](https://lageos.cddis.eosdis.nasa.gov/)
4. Jonathan's Space Report
5. [Source](https://space.skyrocket.de/doc_sdat/lageos.htm)
6. [Source](https://lageos.cddis.eosdis.nasa.gov)