Until now, going into orbit meant moving to a planet or moon and remaining at zero range. As the planet moved, so would the fleet. In situations such as multi-race starts on the same planet this means you can have a lot of hostile warships at range zero from each other and from any ground-based weapons. The only real alternatives are to send them to orbit a moon or some other planet
In v3.2, you can give a fleet an order to go into an orbit some distance from a system body. For example, you might order a couple of destroyers to orbit Earth at 100,000 km. They will move to a point 100,000 kilometers away and will then orbit Earth at that distance without expending fuel. The orbital period will be based on distance from the planet and the mass of the planet. As an example, a ship at 60,000 kilometers will orbit the Earth every 39 hours. The actual formula is:
((Orb distance in kilometers/400000)^3 * 793.64/Planet Mass)^0.5
This will provide much more freedom in positioning units and multi-race starts on Earth could result in many ships orbiting the planet at different ranges and bearings. There is no limit to the range so you could orbit Earth at ten million or a hundred million kilometers if you wish. Ships in orbit will move on their orbital path even if you set their speed to 1. This may also allow you to orbit a ship with engines off toward an enemy force with a much lower chance of detection.
Although planets only move in their orbit during the 5-day increment, because of their generally shorter orbital periods and also because there are a lot fewer fleets than moons and asteroids, fleets in higher orbits will move during every time increment.
Steve