# Magnetospheric Multiscale 3

> spacecraft in the Magnetospheric Multiscale constellation

**Wikidata**: [Q113274714](https://www.wikidata.org/wiki/Q113274714)  
**Source**: https://4ort.xyz/entity/magnetospheric-multiscale-3

## Summary
Magnetospheric Multiscale 3 (MMS 3) is a geomagnetic satellite operated by NASA as part of the Magnetospheric Multiscale Mission. Launched on March 13, 2015, it studies Earth's magnetosphere to understand magnetic reconnection, a fundamental process in space physics.

## Key Facts
- Official name: Magnetospheric Multiscale 3 (MMS 3)
- Aliases: MMS3, Solar Terrestrial Probe 4C, STP 4C, George
- Operator: National Aeronautics and Space Administration (NASA)
- Mission: Magnetospheric Multiscale Mission
- Launch date: March 13, 2015, at 02:44 UTC
- Launch site: Cape Canaveral Space Launch Complex 41
- Launch vehicle: Atlas V 421 (flight AV-053)
- COSPAR ID: 2015-011C
- NSSDCA ID: 2015-011C
- Satellite class: Geomagnetic satellite
- Orbit type: Highly elliptical orbit

## FAQs
### Q: What is Magnetospheric Multiscale 3?
A: MMS 3 is a NASA-operated spacecraft launched in 2015 as part of the Magnetospheric Multiscale Mission. It investigates Earth’s magnetosphere, particularly the phenomenon of magnetic reconnection.

### Q: When was MMS 3 launched?
A: MMS 3 was launched on March 13, 2015, at 02:44 UTC from Cape Canaveral Space Launch Complex 41 using an Atlas V 421 rocket.

### Q: What is the purpose of MMS 3?
A: The primary goal of MMS 3 is to study magnetic reconnection in Earth's magnetosphere, which plays a key role in space weather and energy transfer between the solar wind and planetary environments.

## Why It Matters
Magnetospheric Multiscale 3 contributes critical data toward understanding magnetic reconnection—a universal plasma process occurring throughout the universe but difficult to observe directly. By studying how magnetic fields break and reconnect, scientists gain insights into solar flares, auroras, and the dynamics of Earth’s protective magnetosphere. This knowledge enhances our ability to predict space weather events that can disrupt satellites, communications systems, and power grids. As part of a four-spacecraft constellation, MMS 3 enables high-resolution three-dimensional observations previously impossible with single-satellite missions.

## Notable For
- Part of the first dedicated mission to study magnetic reconnection in detail
- Operates within a precisely coordinated multi-spacecraft formation
- Equipped with advanced instruments capable of measuring electric and magnetic fields at unprecedented temporal resolution
- One of four identical spacecraft enabling stereo imaging of magnetospheric processes
- Launched aboard one of the final configurations of the reliable Atlas V launch system

## Body
### Mission Overview
Magnetospheric Multiscale 3 (MMS 3) is one of four nearly identical spacecraft comprising NASA's Magnetospheric Multiscale Mission. Its objective is to investigate magnetic reconnection in Earth's magnetosphere through precise measurements of electromagnetic fields and particle distributions.

### Designation and Identifiers
The spacecraft carries several official designations:
- SCN (Spacecraft Number): 40484
- COSPAR ID: 2015-011C
- NSSDCA ID: 2015-011C

It also has multiple aliases including MMS3, Solar Terrestrial Probe 4C (STP 4C), and informal name "George."

### Launch Details
MMS 3 was successfully launched on March 13, 2015, at 02:44 UTC from Cape Canaveral Space Launch Complex 41. It rode atop an Atlas V 421 launch vehicle during flight AV-053.

This event marked a major milestone in heliophysics research and represented the culmination of years of planning and engineering development under NASA's Solar Terrestrial Probes program.

### Operational Parameters
As a geomagnetic satellite, MMS 3 operates in a highly elliptical orbit designed to traverse regions where magnetic reconnection commonly occurs—particularly near the dayside magnetopause and in the magnetotail. This orbital path allows repeated sampling of dynamic boundary layers around Earth.

### Scientific Role
Within the MMS constellation, each satellite—including MMS 3—is equipped with identical suites of instruments tailored for fast-response measurement of:
- Electric and magnetic fields
- Ion and electron density and velocity
- Energetic particles

These synchronized observations enable researchers to construct detailed models of magnetic reconnection sites in three dimensions, advancing theoretical understanding of this complex physical process.

## References

1. Jonathan's Space Report