First satellite sub-constellation and offset second satellite sub-constellation

1 . A satellite constellation, comprising:

a first set of satellites configured in a first sub-constellation defined by a first set of orbital elements; and

a second set of satellites configured in a second sub-constellation defined by the first set of orbital elements with a longitudinal offset.

2 . The satellite constellation of claim 1 , wherein the first set of satellites and the second set of satellites comprise an approximately same altitude and orbital inclination and follow an approximately circular orbit.

3 . The satellite constellation of claim 1 , wherein the first sub-constellation and the second sub-constellation comprise a Walker configuration.

4 . The satellite constellation of claim 3 , wherein the Walker configuration comprises a snake (“sigma”) configuration defined by T/P/F where N is equal to a number of satellites and S is a snake family parameter.

5 . The satellite constellation of claim 4 , wherein the longitudinal offset is substantially equal to 90/(S+1) degrees.

6 . The satellite constellation of claim 1 , wherein each satellite of the first set of satellites comprises a buddy communication link with a satellite of the second set of satellites.

7 . The satellite constellation of claim 6 , wherein the first set of satellites and the second set of satellites comprises a same number of satellites;

wherein each satellite of the second set of satellites comprises a buddy communication link with one satellite of the first set of satellites in a one-to-one relationship.

8 . The satellite constellation of claim 6 , wherein each satellite of the second set of satellites comprises a forward communication link with a next satellite of the second set of satellites and comprises a reverse communication link with a previous satellite of the second set of satellites.

9 . The satellite constellation of claim 8 , wherein the first set of satellites and the second set of satellites comprises a same number of satellites;

wherein each satellite of the second set of satellites comprises a buddy communication link with one satellite of the first set of satellites in a one-to-one relationship;

wherein each satellite of the first set of satellites comprises a forward communication link with a next satellite of the first set of satellites and comprises a reverse communication link with a previous satellite of the first set of satellites.

10 . The satellite constellation of claim 9 , wherein each of the buddy communication links comprise substantially permanent buddy communication links.

11 . The satellite constellation of claim 10 , wherein each of the forward communication links comprise substantially permanent forward communication links;

wherein each of the reverse communication links comprises substantially permanent reverse communication links.

12 . A satellite constellation, comprising:

a plurality of satellite buddy pairs configured in a first sub-constellation and a second sub-constellation;

wherein each satellite buddy pair comprises a first satellite of the first sub-constellation and a second satellite of the second sub-constellation that are coupled by a buddy communication link;

wherein the first sub-constellation comprises a Walker snake configuration;

wherein the second sub-constellation comprises the Walker snake configuration with a longitudinal offset.

13 . The satellite constellation of claim 12 , wherein the Walker snake configuration comprises initial locations that substantially follow a ground trace that comprises periodic lobes;

wherein the longitudinal offset is approximately equal to one half a distance between consecutive lobes.

14 . The satellite constellation of claim 13 , wherein the first sub-constellation and the second sub-constellation comprise an approximately same altitude and orbital inclination and follow an approximately circular orbit.

15 . The satellite constellation of claim 12 , wherein each satellite of the first sub-constellation comprises a forward communication link with a next satellite of the first sub-constellation;

wherein each satellite of the first sub-constellation comprises a reverse communication link with a previous satellite of the first sub-constellation;

wherein each satellite of the second sub-constellation comprises a forward communication link with a next satellite of the second sub-constellation;

wherein each satellite of the second sub-constellation comprises a reverse communication link with a previous satellite of the second sub-constellation.

16 . The satellite constellation of claim 15 , wherein each buddy communication link, forward communication link, and reverse communication link comprises a substantially permanent communication link.

17 . A method, comprising the steps of:

launching a first satellite sub-constellation that comprises a plurality of satellites in a Walker snake configuration;

establishing a forward communication link between each satellite of the first satellite sub-constellation and a next satellite of the first satellite sub-constellation;

establishing a reverse communication link between each satellite of the first satellite sub-constellation and a previous satellite of the first satellite sub-constellation;

launching at least one satellite into a second satellite sub-constellation that is longitudinally offset from the Walker snake configuration of the first satellite sub-constellation;

establishing a buddy communication link between the at least one satellite and a corresponding satellite of the first satellite sub-constellation.

18 . The method of claim 17 , wherein the plurality of satellites of the first satellite sub-constellation comprises a first plurality of satellites, wherein the step of launching the at least one satellite into the second satellite sub-constellation that is longitudinally offset from the Walker snake configuration of the first satellite sub-constellation comprises the step of:

launching into the second sub-constellation a second plurality of satellites that correspond to the first plurality of satellites, wherein the first plurality of satellites and the second plurality of satellites comprise a same number of satellites;

wherein the step of establishing the buddy communication link between the at least one satellite and the corresponding satellite of the first satellite sub-constellation comprises the step of:

establishing a buddy communication link between each satellite of the first plurality of satellites a corresponding satellite of the second plurality of satellites;

the method further comprising the steps of:

establishing a forward communication link between each satellite of the second satellite sub-constellation and a next satellite of the second satellite sub-constellation;

establishing a reverse communication link between each satellite of the second satellite sub-constellation and a previous satellite of the second satellite sub-constellation.

19 . The method of claim 18 , further comprising the step of:

sending a message from a first satellite of the first satellite sub-constellation to a second satellite of the second satellite sub-constellation over at least one buddy communication link.

20 . The method of claim 19 , wherein the step of sending the message from the first satellite in the first satellite sub-constellation to the second satellite of the second satellite sub-constellation over the at least one buddy communication link comprises the step of:

bypassing a third satellite of the first satellite sub-constellation to send the message from the first satellite to the second satellite.