Increase Tundra orbit periapsis requirement #2375
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With a 1000 km periapsis (eccentricity 0.82), the resulting orbit has barely any apogee dwell time; it moves west very quickly across the sky when it's at apogee. At an eccentricity of 0.423, the ground track moves from being a figure-of-eight to a teardrop shape. As far as I can tell, this is the highest eccentricity that gives a proper Tundra orbit. A 17000 km periapsis corresponds to an eccentricity of around 0.446, which makes the maximum eccentricity a little higher than that value. Also decreased the minimum eccentricity a little bit. According to Capderou's "Handbook of Satellite Orbits", a 0.2668 eccentricity Tundra orbit was considered for ESA's "Archimedes" telecommunications project.
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With a 1000 km periapsis (eccentricity 0.82), the resulting orbit has barely any apogee dwell time; it moves west very quickly across the sky when it's at apogee.
At an eccentricity of 0.423, the ground track moves from being a figure-of-eight to a teardrop shape. Higher eccentricities make the ground track more of an oblong shape. An eccentricity of 0.423 gives a periapsis altitude of 17958 km; I've rounded it down to 17000 km to give a quite lot of margin.
Also decreased the minimum eccentricity a little bit. According to Capderou's "Handbook of Satellite Orbits", a 0.2668 eccentricity Tundra orbit was considered for ESA's "Archimedes" telecommunications project, giving an 8 hour visibility window per orbit. The new minimum of 0.25 is a little below that value.
Examples of Tundra orbits of varying eccentricity, with a waypoint at 63° latitude and a range of 3000 km:
Implements #2373