# I Enforcing artificial frozen orbit

1. Oct 29, 2017

### a_potato

Hello,
I'm interested in how to formulate a simple constellation in which there are two satellites with identical orbital parameters (eccentricity <0.003, same inclination and aligned arg. Perigee, same RAAN) but which have different altitudes (e.g. Semi major axis) which are around 1000km and offset by a small amount, say 50km.

As the orbits propagate, the arg perigees will precess at different rates. My question is how can I determine delta-v requirements to keep the perigee aligned during orbit evolution (ignoring RAAN precession) and therefore keeping a frozen configuration. Any thoughts welcome.

2. Oct 31, 2017

### stefan r

Earth has a mean radius of 6,371.0 km. The delta-v requirements will be effected by the gravitational pull of the thing your satellites orbit.

3. Oct 31, 2017

### Staff: Mentor

I'm a bit confused why you would call the orbits frozen if their RAAN diverge over time. Why would the perigee be so important if you require the eccentricity to be very small anyway?

4. Nov 1, 2017

### a_potato

mfb- RAAN is not normally considered in a frozen orbit as it must always precess relative to something (e.g. a sun-sync orbit processes relative to an inertial system). Perigee is important in constellations with small altitude separations between orbit planes, such that the apogee of one is higher than the perigee of the next one