AKATSUKI in Highly Elliptical Orbit Around Venus

By Ultraviolet Imager (UVI), at around 2:19 p.m. on Dec. 7 (Japan Standard Time) at the Venus altitude of about 72,000 km. (Credit: JAXA)
By Ultraviolet Imager (UVI), at around 2:19 p.m. on Dec. 7 (Japan Standard Time) at the Venus altitude of about 72,000 km. (Credit: JAXA)

TOKYO (JAXA PR) — The Japan Aerospace Exploration Agency (JAXA) successfully inserted the Venus Climate Orbiter “AKATSUKI” into the orbit circling around Venus.

As a result of measuring and calculating the AKATSUKI’s orbit after its thrust ejection, the orbiter is now flying on the elliptical orbit at the apoapsis altitude of about 440,000 km and periapsis altitude of about 400 km from Venus. The orbit period is 13 days and 14 hours. We also found that the orbiter is flying in the same direction as that of Venus’s rotation.

The AKATSUKI is in good health.

We will deploy the three scientific mission instruments namely the 2μm camera (IR2), the Lightning and Airglow Camera (LAC) and the Ultra-Stable oscillator (USO) and check their functions. JAXA will then perform initial observations with the above three instruments along with the three other instruments whose function has already been confirmed, the Ultraviolet Imager (UVI), the Longwave IR camera (LIR), and the 1μm camera (IR1) for about three months. At the same time, JAXA will also gradually adjust the orbit for shifting its elliptical orbit to the period of about nine days. The regular operation is scheduled to start in April, 2016.

Orbit calculation result (as of Dec. 9)
Periapsis altitudeAbout 400 km
Apoasis altitudeAbout 440,000 km
InclinationAbout 3 degrees against Venus’ revolution plane
PeriodAbout 13 days and 14 hours

Reference 1

Orbit pattern diagram

akatsuki_orbit