# Michibiki 3D model

> Shape built from published dimensions and pictures; details simplified.

Free 3D model of Michibiki, a satellite, built from published dimensions by Space Radar. 11,702 triangles, 58 kB glTF, MIT.

- **Class:** Satellites
- **Mission:** Navigation
- **Triangles:** 11,702
- **File:** michibiki.glb, 58 kB, glTF 2.0 binary (meshopt)
- **Look:** Flat colours
- **Size:** 19 m across
- **Made:** Built from dimensions
- **Added:** 2026-10-13
- **Download:** https://raw.githubusercontent.com/Sara-Managed-Projects/space-radar/main/site/models/michibiki.glb
- **Mirror:** https://git.sara-agent.org/sara-projects/space-radar/raw/branch/main/site/models/michibiki.glb
- **Viewer:** https://www.spaceradar.ai/model/?id=michibiki
- **Licence:** MIT (https://github.com/Sara-Managed-Projects/space-radar/blob/main/LICENSE)
- **Credit:** Michibiki 3D model by Space Radar (spaceradar.ai), MIT License

Canonical: https://models.spaceradar.ai/michibiki/

## How it was made

Built in code from published dimensions and photographs, with no image-to-3D generator and no one else’s mesh. 3D model: built by Space Radar from the dimensions in the Cabinet Office of Japan's QZS-2 satellite information; compared with a render from the Quasi-Zenith Satellite System website (CC BY 4.0).

built by this project in code (the private tool model-from-images: assemble.py, from a yaml of primitives), from the cited dimensions and the pictures under `references`; no image-to-3D model was used, and no published mesh (NASA's 3D Resources on GitHub, 1 583 paths read 2026-10-13, has none of this craft; the survey of 2026-10-13 found no agency model of it under usable terms)

## Dimensions

- Body 1: 2.4 m
- Body 2: 2.4 m
- Height: 6.2 m
- Wing: 8.3 m
- Span: 19 m
- Solar array area: 14.9 m²
- L ant cone bottom: 1.8 m
- L ant cone top: 1.5 m
- L ant cone height: 0.8 m

Source: Cabinet Office, Government of Japan, 'QZS-2 Satellite Information', SPI-QZS2_C (revision C, June 28, 2019), https://qzss.go.jp/en/technical/qzssinfo/khp0mf0000000wuf-att/spi-qzs2_c.pdf, OPENED 2026-10-13 (the list it hangs from: https://qzss.go.jp/en/technical/qzssinfo/index.html), section 6 'Geometry', 'Figure 4 Satellite dimensions' '(Unit: mm)', whose dimension lines read 8300, 2400, 8300 (each wing, the body, the other wing: 19.0 m tip to tip), 6200 (height, nozzle to antenna top), 2400 and 2850 (the body and the antenna deck seen from the wing's side); Table 4 'Optical properties': 'SAP 14.9' m2 on each Y face, '+Y MLI 6.2, Radiator 3.9', '-Y MLI 5.7, Radiator 4.4', '+X MLI 10.1', '-Z MLI 5.6'; its note 1: 'L-ANT shape is approximately depicted as a truncated circular cone comprised of Ø1.5m and Ø1.8m circles 0.8m apart'; section 2: 'The +Z-axis is oriented to the bore sight direction of the L-ANT antenna. The +Y-axis is parallel to the rotation axis of the solar panels'; section 3 'Attitude Law': 'Yaw steering mode: The +z-axis is pointing to the Earth. The y-axis is oriented perpendicular to the plane made up by the Sun, Earth and satellite.' The same office's documents for the other craft (SPI-QZS1R_A, SPI-QZS3_F, SPI-QZS6, opened the same day) give the same 14.9 m2 arrays; the drawing of QZS-1R shows A FLAT ANTENNA DECK WITH NO CONE, and eoPortal, https://www.eoportal.org/satellite-missions/qzss, OPENED 2026-10-13, says: 'QZS-1, QZS-2, and QZS-4 have L-band antennas that are helical array antennas, but QZS-3 uses a flat patch antenna', so THIS FILE IS QZS-2 AND QZS-4 ONLY. JAXA, https://global.jaxa.jp/countdown/f18/overview/michibiki_e.html, OPENED 2026-10-13, of the FIRST Michibiki (retired): '2.9m in depth x 3.1m in width x 6.2m in height (Length between the tips of the paddles: 25.3 m)'. DERIVED: the body's box is 4.25 m long (a 10.1 m2 side face over 2.4 m); each wing is two panels of 3.2 x 2.33 m (14.9 m2) on a 1.9 m yoke. READ OFF THE DRAWING, which is not reproduced: where the wings stand on the body, the deck's two small helical antennas and the corner reflector, the nozzle. Colours are the render's: a black blanket, silver radiators, a white antenna cover.

## References

- [QZS-1R CG05](https://commons.wikimedia.org/wiki/File:QZS-1R_CG05.png), Quasi-Zenith Satellite System website, Cabinet Office of Japan (CC BY 4.0 (Cabinet Office of Japan, Quasi-Zenith Satellite System website, qzss.go.jp/overview/download/cg-image1r.html))