# What is ESA's Solar Orbiter's target inclination?

The BBC News article European SolO probe ready to take on audacious mission links to the ESA video shown below and contains this 5 minute audio interview with NASA deputy project scientist on the mission Holly Gilbert who outlines several interesting aspects of the mission and complementary measurements with Parker Solar Probe.

She mentions somewhere (I don't have the time code) that the Solar Orbiter will have a view of the Sun's poles, and the video shows what looks like an inclined elliptical orbit.

What inclination are they targeting? I couldn't find any information about that on the ESA page https://sci.esa.int/web/solar-orbiter/ and this ESA Red Book is from 2011, so it may not contain up-to-date information.

The inclination will be adjusted a few times during the mission:

The nominal mission of seven years will see a maximum orbital inclination relative to the solar equator of 25°. During the extended mission, additional Venus GAMs could allow the orbital inclination to increase to about 34°. The main scientific activity will take place during the near-Sun encounter and high-latitude parts of each orbit, with different science goals envisioned for each orbit.

From Solar Orbiter: Exploring the Sun-heliosphere connection (ArXiv, Researchgate, and published in Solar Physics) Figure 3 shows the solar latitude of the spacecraft versus time, and the extrema reflect the orbit's inclination for a January 2017 launch which didn't happen. While the orbit will be different, this at least illustrates how the inclination was planned to slowly increase over time after each orbit-lowering flyby. (For example, this paywalled paper lists the launch date as Jan-2017 (Mar-2017 and Sep-2018 back-ups))

after flyby        approx. date   approx. inc
-----------        ------------   -----------
Venus 1            06-2017           7
Earth 1            04-2018          14
Earth 2 + Venus 2  06-2020          17
Venus 3            04-2022          25
Venus 4            01-2024          31
Venus 5            04-2025          34


Figure 3 Mission profile for a January 2017 launch, showing heliocentric distance (top) and latitude (bottom) of Solar Orbiter as a function of time. Also indicated are the times at which gravity assist maneuvers at Venus and Earth occur (blue).