Orbit that does not need maneuvering

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Imagin_e
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Hi!

This is a textbook problem that I need help with (I want to practice as much as I can before the exams) and I hope that there is someone who can guide me. The question is:
You’re doing a first-order analysis on a new satellite in an elliptical (e = 0.2) orbit at 700 km altitude. Can you design the orbit so no maneuvers are necessary to maintain it? Hint: consider secular J2 perturbations only – can the effects of Ω counteract with ω? If it can’t be done at 700 km, is another altitude feasible?

Homework Equations


See below

The Attempt at a Solution


I used the following equations (for J2 perturbations) :
upload_2016-10-16_21-36-42.png


And for p and n:
upload_2016-10-16_21-36-36.png


I inserted n and p into the first two equations and got:

upload_2016-10-16_21-37-26.png


I assumed that they were all constant, so I ended up with:
upload_2016-10-16_21-39-17.png
upload_2016-10-16_21-39-31.png


And this gave me of i1 = 90° and i2=63°. If we have these inclinations then there is no need for maneuvering. And now for the next question:

The next question to answer is can the effects of Ω counteract with ω? If it can’t be done at 700 km, is another altitude feasible? I have no idea how to answer this question.

As you can see I may be completely lost. I don't see my solution feasible since it doesn't actually answer the question about the no maneuvering bit. Anyone that can help me? Thanks!
 
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