Raijin-2: Japan's Advanced Earth Observation Microsatellite
The Raijin-2 (also known as Rising-2) is a sophisticated Japanese microsatellite designed for high-precision Earth observation. Launched in 2014 and operated by Tohoku University, this spacecraft represents a significant achievement in miniaturized space technology, combining a powerful optical system with a variety of specialized sensors to monitor our planet from orbit.
Key Facts
- Operator: Tohoku University
- Launch Date: May 24, 2014
- Launch Vehicle: H-IIA 202
- Primary Instrument: Cassegrain telescope with 5m nadir resolution
- Mission Duration: Over 12 years and ongoing
- Orbital Inclination: 97.9°
Technical Design and Architecture
Raijin-2 is built around a specialized Cassegrain telescope—a reflecting telescope design that folds the light path to allow a long focal length (1 meter) within a compact body (10 cm diameter). This allows the satellite to capture high-resolution imagery despite its small size.
The spacecraft utilizes an unusual central-pillar bus architecture, a design inherited from the earlier Sprite-Sat mission. To maintain its precise orientation in space, the satellite employs reaction wheels and magneto-torquers, achieving an angular accuracy of 0.1 degrees.
Power is supplied by Gallium Arsenide (GaAs) solar cells mounted directly on the spacecraft body, providing an estimated electrical power output of 47.6W.
[ไม่มีภาพประกอบ]Scientific Instrumentation
To achieve its Earth observation goals, Raijin-2 carries a diverse suite of instruments that capture data across different spectrums and scales:
- HPT (High Precision Telescope): The main telescope providing 5m resolution at nadir (the point directly below the satellite), operating in visible and near-infrared bands.
- BOL (Bolometer Array Camera): A specialized sensor used for measuring cloud temperatures.
- WFC (Wide Field-of-View CCD Camera): A camera designed to capture broad areas of the Earth's surface.
- LSI-N and LSI-W: Two CMOS medium field-of-view cameras dedicated to near-infrared imaging.
- VLF-ANT, R: A radio antenna specifically designed to receive signatures of lightning events.
Mission Specifications
Launched from the Tanegashima Space Center via an H-IIA 202 rocket, Raijin-2 operates in a geocentric orbit with a period of 97.5 minutes. Its orbit is nearly circular, with a perigee (lowest point) of 629.8 km and an apogee (highest point) of 647.4 km.
| Parameter | Detail |
|---|---|
| COSPAR ID / SATCAT | 2014-029D / 39769 |
| Launch Mass | 42 kg (93 lb) |
| Eccentricity | 0.0013 |
| Inclination | 97.9° |
| Power Source | GaAs Solar Cells (47.6W) |
Frequently Asked Questions
Who operates the Raijin-2 satellite?
The Raijin-2 microsatellite is operated by Tohoku University.
What is the primary purpose of the HPT instrument?
The HPT is the main telescope used for high-resolution imaging, offering 5m resolution at nadir in both visible and near-infrared bands.
How does Raijin-2 maintain its position in space?
The satellite uses a combination of reaction wheels and magneto-torquers to achieve an angular accuracy of 0.1 degrees.
What is the significance of the VLF-ANT, R instrument?
This radio antenna is specifically designed to detect and receive signatures associated with lightning events on Earth.
How long has the mission been active?
Since its launch on May 24, 2014, the mission has been ongoing for over 12 years and 2 months.