Akatsuki (spacecraft)

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Akatsuki

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)[1]
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[1]
Start of mission
Launch date	21 May 2010, 21:58:22 (2010-05-21UTC21:58:22Z) UTC[2]
Rocket	H-IIA 202
Launch site	Tanegashima YLP-1
End of mission
Declared	29 May 2024
Last contact	April 2024
Orbital parameters
Reference system	Cytherocentric
Eccentricity	0.971
Pericytherion altitude	1,000–10,000 kilometers (620–6,210 mi) changing periodically[3]
Apocytherion altitude	370,000 kilometers (230,000 mi)[3]
Inclination	3.0°
Period	10.8 days[4]
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[5][6]
PLANET series ← Nozomi

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,^[7] 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.^[5][6][8][9]

By using five different cameras working at several wavelengths, Akatsuki is studying the stratification of the atmosphere, atmospheric dynamics, and cloud physics.^[10][11] Astronomers working on the mission reported detecting a possible gravity wave (not to be confused with gravitational waves) in Venus' atmosphere in December 2015.^[12]

JAXA lost contact with the probe sometime in April 2024