Tractor beams aren’t a new idea to any one that has watched or read science fiction. The tech in fiction can do things like capture space ships and lots more. In the real world, science is trying to capture much smaller things with tractor beams. Laser beams have been able to be used to capture things for a while on the nano and microscopic scale.
Lasers can be used for instance to manipulate single cells, molecules, viruses, and other tiny objects. The tractor beam can be used to push or pull these little objects. NASA is working on tractor beam tech not for manipulating cells in space, but to help its rovers on the surface of some distant planet to capture samples.
NASA hopes to one day perfect a small-scale tractor beam that it can fit to future rovers allowing the rover to capture samples of things like dust and gas. We have talked about tractor beams before when Chinese physicists were working on the tech for use in moving particles at the nano level.