# Arase

> Japanese satellite which studies the Van Allen belts

**Wikidata**: [Q17012906](https://www.wikidata.org/wiki/Q17012906)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Arase_(satellite))  
**Source**: https://4ort.xyz/entity/arase

## Summary
Arase, also known as ERG (Exploration of energization and Radiation in Geospace), is a Japanese geomagnetic satellite operated by the Japan Aerospace Exploration Agency (JAXA). Launched on December 20, 2016, its primary mission is to study the Van Allen belts and analyze the dynamics of the Earth's magnetosphere.

## Key Facts
*   **Official Name:** Exploration of energization and Radiation in Geospace (ERG), also referred to as SPRINT-B.
*   **Classification:** Geomagnetic satellite designed to monitor Earth's magnetosphere.
*   **Operator:** Japan Aerospace Exploration Agency (JAXA).
*   **Launch Date:** December 20, 2016, at 11:00:00 UTC.
*   **Launch Vehicle:** Epsilon rocket (E-2 configuration).
*   **Launch Site:** Uchinoura Space Center, Japan.
*   **Mass:** 350 kilograms (launch weight).
*   **Power Source:** Spacecraft solar array comprising 4 panels.
*   **Predecessor:** Hisaki (a decommissioned Japanese ultraviolet astronomy satellite).
*   **Identifiers:** COSPAR ID 2016-080A; NSSDCA ID 2016-080A.

## FAQs
### Q: What is the primary purpose of the Arase satellite?
A: Arase is designed to study the Van Allen belts, specifically focusing on the exploration of energization and radiation in geospace. It monitors the Earth's magnetosphere to understand how high-energy electrons are created and disappear.

### Q: When and how was Arase launched?
A: Arase was launched on December 20, 2016, at 11:00:00 UTC from the Uchinoura Space Center in Japan. It was deployed using an Epsilon launch vehicle (E-2 configuration).

### Q: Who operates the Arase satellite?
A: The satellite is operated by the Japan Aerospace Exploration Agency (JAXA).

## Why It Matters
Arase plays a critical role in space physics and weather research by directly observing the radiation belts surrounding Earth. The Van Allen belts contain high-energy particles that can pose significant risks to satellites and astronauts. By studying the "energization and radiation" dynamics within these belts—explicitly referenced in the satellite's alternative name, ERG—Arase helps scientists understand the mechanisms behind geomagnetic storms and space weather phenomena.

As a dedicated geomagnetic satellite, it provides essential data on how energy flows through the magnetosphere. This research is vital for improving models used to protect space-based infrastructure from hazardous space environments. The mission succeeded the decommissioned Hisaki satellite, continuing Japan's specific focus on space science and astrophysics using small- to medium-class spacecraft launched efficiently via the Epsilon rocket.

## Notable For
*   **Specialized Mission:** Specifically designed to analyze the Van Allen belts and geospace energization, distinguishing it from general Earth observation satellites.
*   **Efficient Launch Platform:** Utilized the Epsilon rocket, a Japanese solid-fuel launch vehicle known for its ability to deploy satellites with reduced cost and preparation time.
*   **Compact Design:** Despite its complex mission to monitor the magnetosphere, it maintains a launch weight of only 350 kg.
*   **Mission Lineage:** Follows the scientific mission path of the Hisaki satellite, contributing to a continuous data stream regarding space environments.

## Body
### Mission Overview
Arase is a geomagnetic satellite that serves as a space observatory for the Earth's magnetosphere. The mission aims to elucidate the generation mechanisms of relativistic electrons in the Van Allen radiation belts. The satellite is also known by the names **ERG**, **SPRINT-B**, and **Energization and Radiation in Geospace**.

### Technical Specifications
The spacecraft has a launch mass of **350 kilograms**. It is powered by a **spacecraft solar array** consisting of **4 panels**. It is tracked under the international designator **2016-080A**.

### Launch and Deployment
The satellite was successfully delivered to orbit via a significant **rocket launch** event.
*   **Date:** December 20, 2016
*   **Time:** 11:00:00
*   **Location:** Uchinoura Space Center (Japan)
*   **Vehicle:** Epsilon (specifically the E-2 variant)

The Epsilon rocket is a Japanese launch vehicle noted for its use in satellite deployment. The launch was managed by the **Japan Aerospace Exploration Agency**, which also serves as the satellite's operator.

### Program Context
Arase is part of a series of Japanese scientific endeavors in space. It **follows** the **Hisaki** satellite, an ultraviolet astronomy satellite that has since been decommissioned. The progression from Hisaki to Arase represents a continued commitment to observing astrophysical and heliophysical phenomena.

## References

1. [Source](https://space.skyrocket.de/doc_sdat/sprint-b.htm)
2. Jonathan's Space Report