> By changing orientation they can control the speed/direction in which they slow down. I apologize for not communicating clearly but that is the impossible pa

> By changing orientation they can control the speed/direction in which they slow down. I apologize for not communicating clearly but that is the impossible part. It will only work if the interstellar wind is, to borrow nautical terms, "in irons" or "running" (in line with either from ahead or behind the direction of travel) and that is impossible to either know, predict, or assume. From all other directions there are lateral forces that are impossible to overcome. For example, if you are in a sailboat following another sailboat in calm waters with consistent wind and the lead sailboat slows down or the trailing puts out more sail to speed up to narrow a gap, one of the two will fall out of the line of travel due to lateral forces and will be forced to apply rudder to compensate. These things have no rudders. The same thing happens to airplanes. If they increase or decrease drag either altitude or speed (or both) changes and control inputs are needed maintain position. There is no ocean of water or air in space in which to steer. I suppose if we launch and preposition several hundred billion space weather stations along the route in advance, we will understand the forces involved and be able to set the swarm components off on the trajectory needed so that the drag plan will work.