Sun-Synchronous Orbit Designer
Find the retrograde inclination that makes Earth's J2 nodal precession match the Sun's apparent annual motion. The default target is one tropical year.
SSO design point
Required inclination
98.208 deg
retrograde sun-sync plane
RAAN precession
0.985647 deg/day
360.00 deg/year target
Orbital period
98.88 min
a = 7083.1 km
Local time drift
0.0000 min/day
near zero means Sun-synchronous
Sun-synchronous geometry
J2 precession rotates the node line with the Sun.
A retrograde orbit uses J2 precession to rotate its node line with the Sun, preserving nearly constant local solar time.
Open Source and Easy to Use Elsewhere
This tool is open source and the underlying logic is fully transparent. You can inspect the code, understand the calculations, and contribute improvements. If you want to use the tool in your own website, course page, or learning platform, you can also embed it directly and start from a ready-made iframe setup for this exact tool.
Open source: review the implementation and see how the results are produced.
Embeddable: preview this tool, copy the iframe, and use it in your own site or LMS.