When NASA needs to make repairs to the Hubble Space Telescope, astronauts have to be specially trained to get out of the Space Shuttle for extravehicular activity. They also have to learn how to work within the confines of their space suits, with thick gloves on. Wouldn't it be nice to just bring the telescope inside, where repairs wouldn't be so challenging and dangerous?
In science fiction, space ships including the Starship Enterprise snatch each other up using tractor beams. In some cases, large vessels have a tractor beam strong enough to prevent smaller vessels from escaping the gravitational force. So is this science even plausible?
Yes and no. Optical tweezers are as close as you're going to get to a legitimate tractor beam on current-day Earth. Scientists have harnessed small lasers into beams capable of manipulating molecules and moving them with precision. Optical tweezers use a focused laser to trap and suspend microscopic particles in an optical trap. Scientists can use optical tweezers to trap and remove bacteria and sort cells. Optical tweezers are used primarily in studying the physical properties of DNA. While the beams used in optical tweezers aren't strong enough to dock the space shuttle to the International Space Station, it's a start in that direction.