Increasing numbers of smaller, more cost effective telecommunications satellites are being launched into the Earth’s orbit, which has led to a growing need for high precision, high reliability bearings to support on-board sub-systems such as reaction wheels and other critical mechanisms, says Gary Hughes, Product Engineering Manager at Schaeffler subsidiary, The Barden Corporation (UK) Ltd.
In the past, building and launching a civil telecommunications satellite into space required a multi-million pound investment, but more recently, the size and cost of satellites have reduced. An increasing number of satellites are now being launched into space from Europe, USA, China, Turkey, India and the Far East.
For bearing suppliers such as Barden UK, high requirements are now being placed on bearings that support satellite sub-systems such as reaction wheels and other on-board precision mechanisms.
A reaction wheel is a type of flywheel used primarily by spacecraft and satellites for attitude control without using fuel for rockets or other reaction devices. A satellite typically comprises three reaction wheels (for X-, Y- and Z-axes), which are particularly useful when the spacecraft must be rotated by very small degrees. They may also reduce the mass fraction needed for fuel. This is accomplished by equipping the satellite with an electric motor attached to a flywheel which, when its rotation speed is changed, causes the satellite to begin to counter-rotate proportionately through conservation of angular momentum.