Akatsuki (spacecraft)

Akatsuki
A model of the spacecraft Akatsuki
NamesVenus Climate Orbiter (VCO)
PLANET-C
Mission typeVenus orbiter
OperatorJAXA
COSPAR ID2010-020D Edit this at Wikidata
SATCAT no.36576
WebsiteJAXA
JAXA Special Site
Mission duration13 years, 11 months
Spacecraft properties
ManufacturerNEC Space Technologies
Launch mass517.6 kg (1,141 lb)[1]
Dry mass320 kg (710 lb)
Dimensions1.04 × 1.45 × 1.44 m (3.4 × 4.8 × 4.7 ft)
Power>700 watts at 0.7 AU[1]
Start of mission
Launch date21 May 2010, 21:58:22 (2010-05-21UTC21:58:22Z) UTC[2]
RocketH-IIA 202
Launch siteTanegashima YLP-1
End of mission
Declared29 May 2024
Last contactApril 2024
Orbital parameters
Reference systemCytherocentric
Eccentricity0.971
Pericytherion altitude1,000–10,000 km (620–6,210 mi)[3]
Apocytherion altitude370,000 km (230,000 mi)[3]
Inclination3.0°
Period10.8 days[4]
Flyby of Venus (failed insertion)
Closest approach6 December 2010, 23:49:00 UTC
Distance550 kilometers (340 mi)
Venus orbiter
Orbital insertion7 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, 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,[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][13]

JAXA lost contact with the probe in late April 2024.[14]

  1. ^ a b Cite error: The named reference Takeshi2011 was invoked but never defined (see the help page).
  2. ^ Stephen Clark (20 May 2010). "H-2A Launch Report – Mission Status Center". Spaceflight Now. Archived from the original on 20 May 2010. Retrieved 20 May 2010.
  3. ^ a b Cite error: The named reference jaxapdf was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference insertion TJT was invoked but never defined (see the help page).
  5. ^ a b Szondy, David. "Akatsuki probe enters orbit around Venus". Retrieved 7 December 2015.
  6. ^ a b Clark, Stephan. "Japanese probe fires rockets to steer into orbit at Venus". Retrieved 7 December 2015.
  7. ^ Chris Bergin (20 May 2010). "AXA H-IIA carrying Akatsuki and IKAROS launches at second attempt". NASASpaceFlight. Retrieved 19 November 2010.
  8. ^ Limaye, Sanjay. "Live from Sagamihara: Akatsuki Orbit Insertion – Second Try". Retrieved 7 December 2015.
  9. ^ Wenz, John (21 September 2015). "Japan's Long Lost Venus Probe May Boom Back to Life". Popular Mechanics. Retrieved 14 October 2015.
  10. ^ Cite error: The named reference Nakamura_2011 was invoked but never defined (see the help page).
  11. ^ "Exploring the Venusian Atmosphere – AKATSUKI/PLANET-C". Akatsuki Special Site. Retrieved 5 December 2015.
  12. ^ Cite error: The named reference NYT-20170116 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference Fukuhara_2017 was invoked but never defined (see the help page).
  14. ^ Jones, Andrew (31 May 2024). "Japan loses contact with Akatsuki, humanity's only active Venus probe". space.com. Retrieved 4 October 2024.