They circle in a "Sun-synchronous" orbit of approximately 810 - 850 kilometers, and each observes the entire Earth twice a day.
(They; circle; L:in a "Sun-synchronous" orbit of approximately 810 - 850 kilometers) (each; observes; the entire Earth; T:twice a day)
They each
circle observes
L:in a "Sun-synchronous" orbit of approximately 810 - 850 kilometers
the entire Earth T:twice a day