Navigational deflector

In the Star Trek fictional universe, the navigational deflector is a device found on many Starfleet ships capable of warp travel, generally noticeable by its foremost location on many ships' engineering hulls and its soft blue glow. The navigational deflector is used while moving at faster-than-light speeds to prevent damage to ships' hulls from micrometeors and friction from the microscopic objects and extremely thin gas found in interstellar space. Deflectors accomplish the first goal through the use of powerful deflector/tractor beams extending several thousand kilometers fore of their ships, aimed automatically through use of the ships' long-range sensors. The deflection of smaller objects and stray atoms is done by largely static low-power deflector shields generated by the deflector.

The beams and shields created by the deflector are often a source of subspace distortion and EM radiation, which can interfere with the operation of ships' sensors. Due to this, long-range sensor arrays are often placed circularly around navigational deflectors. This allows the sensors to look along the same axes of the beams and shields to reduce interference and also, because of their close proximity to the deflector, allows for the speedy receipt of data from them by the computer in control of the device.

The hardware used in navigational deflectors can be quickly reconfigured to produce a variety of particle streams and energy emissions, making them a sort of 'Swiss army knife' for Starfleet vessels.

Navigational deflectors are not seen on a few Starfleet craft, such as the Miranda, Soyuz, and Constellation classes. These classes perform the same functions by use of bow-mounted tractor emitters and low-power use of the deflector grid. Many alien ships also do not have deflector dishes and presumably operate similarly.