Actually that answers my question. Last one. So is having 2 RWSs just in case one goes down?
About Upcoming ISS Reboost http://www.roscosmos.ru/main.php?id=2&nid=8910In accordance with the International Space Station mission ballistics support program, ISS reboost is scheduled for March 24.The maneuver is to be assisted by 8 attitude thrusters of the Progress M-04M cargo vehicle attached to the Zvezda instrumentation compartment. The engines will be started at 12:15 Moscow time (09:05 GMT). Estimated value of the burn is 1 mps. As a result of the maneuver which is to last 425 sec, the altitude of the station shall become 1.7km higher, or to achieve 348km. MCC PAO