Akatsuki (spacecraft)
Akatsuki (あかつき, 暁, "Dawn"), also known as the Venus Climate Orbiter (VCO) and Planet-C, is 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 alternative Venusian elliptic orbit on 7 December 2015 by firing its attitude control thrusters for 20 minutes and made it the first Japanese satellite orbiting Venus.
A model of the spacecraft Akatsuki | |
| Mission type | Venus orbiter |
|---|---|
| Operator | JAXA |
| COSPAR ID | 2010-020D |
| SATCAT no. | 36576 |
| Website | JAXA JAXA Special Site |
| Mission duration | ~2 years (science phase) elapsed: 13 years, 10 months and 29 days |
| Spacecraft properties | |
| Manufacturer | NEC Space Technologies |
| Launch mass | 517.6 kg (1,141 lb) |
| Dry mass | 320 kg (710 lb) |
| Dimensions | 1.04 m × 1.45 m × 1.44 m (3.4 ft × 4.8 ft × 4.7 ft) |
| Power | >700 watts at 0.7 AU |
| Start of mission | |
| Launch date | 20 May 2010, 21:58:22 UTC |
| Rocket | H-IIA 202 |
| Launch site | Tanegashima YLP-1 |
| Orbital parameters | |
| Reference system | Cytherocentric |
| Eccentricity | 0.971 |
| Pericytherion altitude | 1,000–10,000 kilometers (620–6,210 mi) changing periodically |
| Apocytherion altitude | 370,000 kilometers (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 |
By using five different cameras working at several wavelengths, Akatsuki is studying 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' atmosphere in December 2015.