Bob,

If you look at the TLE for RS 44 you will see that the argument of perigee currently is near 139 degrees. Since this value is between 0 and 180 degrees, that means that the perigee (the low point of the orbit) is over the northern hemisphere. Therefore the apogee (the high point of the orbit) is over the southern hemisphere. But if you monitor the TLEs for RS 44 over a longer period you will notice that the value of the argument of perigee drifts. As soon as that value comes between 180 and 360 degrees, the apogee is over the northern hemisphere.

Usually the argument of perigee of satellites will drift. How fast it drifts depends on the orbit inclination. There is only one situation where the argument of perigee does not drift. That is when the inclination has a value of 63.435 degrees. Then the latitude of both perigee and apogee will remain constant.

Hope this helps.

73, Nico PA0DLO

On 25-07-2020 10:09, 73 Bob W7LRD via AMSAT-BB wrote:

Hi-RS44 varies in altitude from about 1180 to about 1525. Seemingly always in the southern hemisphere. I'm trying to wrap my head around the orbital mechanics and getting nowhere. Does the maximum height ever get to the northern hemisphere? I'm obviously missing something here, a little help please. 73 Bob W7LRD _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://www.amsat.org/mailman/listinfo/amsat-bb