We now know that this apparent retrograde motion happens because Earth is constantly moving in its orbit. As our planet ... That situation is called "sun-synchronous" and would force one side ...

It stands at 82 feet (25 meters) tall and can deliver a payload of up to 474 pounds (215 kilograms) to a 310-mile-altitude (500 kilometers) sun-synchronous orbit. Eris consists of three stages and ...