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)
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.
| Periapsis altitude | About 400 km |
| Apoasis altitude | About 440,000 km |
| Inclination | About 3 degrees against Venus’ revolution plane |
| Period | About 13 days and 14 hours |
Reference 1
Orbit pattern diagram
6 responses to “AKATSUKI in Highly Elliptical Orbit Around Venus”
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“We also found that the orbiter is flying in the same direction as that of Venus’s rotation.”
What a pleasant surprise!!! (Unless they actually wanted to approach the planet from the other side…)
Lost in translation? Given Akatsuki’s handicap, they really didn’t have that great a control over its orbit. They were probably just hoping for capture of any kind.
Yes, that’s what I actually thought. I just couldn’t suppress my sarcastic side. 😉
It sounds like they hit the orbit they were describing before, and with an orbit that elliptical, it doesn’t take a lot to make a big difference. There was a lot of uncertainty over how well the spacecraft would actually perform after its long roast in solar orbit, but I’m pretty sure they were at least certain which side it was passing the planet on.
As if Venus rotated.
They obviously had margin enough to choose a great orbit. The eccentricity varies between the altitude of ISS and a Lunar distance. It is synchronized with the wind speeds in Venus’ upper atmosphere, which does rotate. Maybe there the misunderstanding. See Emily Lakdawalla.
Well done Japan! You grabbed victory from the jaws of defeat. I’ll be very excited to see the data you produce