The tractor beam is pretty much a soft SF technology; even if such a device were used in hard SF, it would probably be referred to in more descriptive terms (i.e. a graviton stream or somesuch, though Bob knows there've been enough of those in Star Trek). IIRC, tractor beams as portrayed in the Trek universe are capable not only of pushing and pulling, but also dragging from side to side, which is particularly unlikely as forces in the real world tend either to attract or repel.