Akatsuki (spacecraft)
A model of the spacecraft Akatsuki | |
| Names | Venus Climate Orbiter (VCO) PLANET-C |
|---|---|
| Mission type | Venus orbiter |
| Operator | JAXA |
| COSPAR ID | 2010-020D |
| SATCAT no. | 36576 |
| Website | JAXA JAXA Special Site |
| Mission duration | 13 years, 11 months |
| Spacecraft properties | |
| Manufacturer | NEC Space Technologies |
| Launch mass | 517.6 kg (1,141 lb) |
| Dry mass | 320 kg (710 lb) |
| Dimensions | 1.04 × 1.45 × 1.44 m (3.4 × 4.8 × 4.7 ft) |
| Power | >700 watts at 0.7 AU |
| Start of mission | |
| Launch date | 21 May 2010, 21:58:22 UTC |
| Rocket | H-IIA 202 |
| Launch site | Tanegashima YLP-1 |
| End of mission | |
| Declared | 18 September 2025 |
| Last contact | April 2024 |
| Orbital parameters | |
| Reference system | Cytherocentric |
| Eccentricity | 0.971 |
| Pericytherion altitude | 1,000–10,000 km (620–6,210 mi) |
| Apocytherion altitude | 370,000 km (230,000 mi) |
| Inclination | 3.0° |
| Period | 10.8 days |
| Flyby of Venus (failed insertion) | |
| Closest approach | 6 December 2010, 23:49:00 UTC |
| Distance | 550 kilometers (340 mi) |
| Venus orbiter | |
| Orbital insertion | 7 December 2015 |
PLANET series | |
Akatsuki (あかつき, 暁; "Dawn"), also known as the Venus Climate Orbiter (VCO) and Planet-C, was a Japan Aerospace Exploration Agency (JAXA) space probe tasked with studying the atmosphere of Venus. It was launched aboard an H-IIA 202 rocket on 20 May 2010, but failed to enter orbit around Venus on 6 December 2010. After the craft orbited the Sun for five years, engineers successfully placed it into an alternate Venusian elliptic orbit on 7 December 2015 by firing its attitude control thrusters for 20 minutes, making it the first Japanese satellite to orbit Venus.
By using five different cameras working at several wavelengths, Akatsuki studied the stratification of the atmosphere, atmospheric dynamics, and cloud physics. Astronomers working on the mission reported detecting a possible gravity wave (not to be confused with gravitational waves) in Venus's atmosphere in December 2015.
JAXA lost contact with the probe in late April 2024. Operation was terminated officially on 18 September 2025.