Support heliosynchronous orbit creation for other planets

The classmethod Orbit.heliosynchronous uses the raan_from_ltan, which at the moment only works for the Earth.

[noc0lour]

Hi all, resolving this issue sufficiently for other planets than earth is quite tricky as you need to find:

• formulas for attitude of planet at a specific point of time (where is the defined zero meridian)
• equation of time (calculate local true solar time (LTST), local mean solar time (LMST))

Goal of this exercise is to find the correct RAAN for a given point in time so the ascending node is crossed at LTAN/LTDN.

In this case the local planet time does not line up with Earth time, so LTAN/LTDN are in LMST at a given longitude of a planet. This calculation then ensures you can place a spacecraft in a dawn-dusk orbit propagating along the day/night line (continuous illumination).

For Mars you can look up the equation of time as studied by NASA, also they give formulas for the planet attitude so you can transform from/to local coordinate system.

[iamabhishek0]

@priyanshurohilla From 18 days for 2 lines of code, Strange! Btw it is still open you can work on it, I just made a temporary fix. This issue is all yours now. 😃