Tractor Beams and Gravity and salvaging in space

I wanted to build a salvage ship. I had ship-mounted grinders but they are useless because whenever you bump a block in space it goes flying off. I had gravity generators. But the gravity generators wouldn't work on grids - just characters. And you could not shape the gravity field like you can the sensors or the selection areas for the "P" partial copy mode.

If you want to do meaningful space salvage you need to be able to hold the target grid as it breaks apart and you could do that with a gravity generator that produced a shaped field. On planets you could create fields stronger than the planet's gravity to pick up things that were not held in place by the planet's gravity. You could even create "lift tubes" that gently overcame planet gravity to move people and cargo through tubes.

I suggest three changes.

1) Add a shaped field to the gravity generators with parameters like those of sensors.

2) Create smaller gravity generators that have limited gravity generation ability.

3) Expand the grinding area of the ship sized grinders to there is area around the head of the grinder that allows for multiple grinders' working areas to overlap.