NEW ASTEROID REDIRECTION PROJECTS
Revolutionary ways to remove asteroids out of orbit.
Super-gripper
Although the machine has much potential, there are lots of errors. To begin with, the "arms" can only retract to about 45 degrees. The gripper will not be able to grip asteroids that make the gripper go more than 45 degrees. Furthermore, the main concept is using tiny hooks to grip the asteroid. What will happen if the asteroid is smooth, or the hooks break, the machine will be useless. On top of that, although the machine grips the asteroid, a human has to lift the the machine. What if the asteroid is too heavy to carry. There is lots of tiny contraptions in the machine, if even one part breaks or malfunctions, the whole mission is ruined because there is no replacements in space.
Solar Sail
Although the idea seems very promising, there are lots of room for error. For example, what happens if Aphophis travels too fast that the material rips off. In addition, there is a great difficulty for the material to make contact with the asteroid. Since the material has no thrusters attached to it, it is required to be perfect on the first time. There is no second chance because you will not be able to get it back. Furthermore, there is lots of potential for the heat from the sun to burn the material. The material is a very thin and fragile substance, so if it is ripped or ruined, the plan would result in a fail.
Coating the asteroid
The idea seems easy on paper, but very difficult in reality. For example, it will be quite difficult to coat the asteroid. This will most likely require multiple rockets to travel to the asteroid. Also, how can the asteroid even be coated? It will be extremely difficult and time consuming for humans to coat the asteroid. At the same time, since it takes a long time for the plan to work, the asteroid has to be coated long before it makes contact with anything. If anything goes wrong, it will be too late because it take long for the plan to work.
Gravity Tractor
The plan seems far-fetched and unable to achieve with modern technology. To begin with, it would require much thrust and power to take the tractor to space. Furthermore, the tractor can intercept the asteroid from about 50 metres away, but what if the the asteroid is travelling to fast and there is not enough gravitational force to change its trajectory. Unless there is an outer space freeze gun that can slow asteroids, which there is not, the plan cannot be hoped to work.
Gravitational Slingshot
Although has a very high chance to work, there is one problem. The Ion thrusters will attach to the asteroid when it is near the moons atmosphere. That is approximately 384 400 km away. I do not believe that the thrusters do not have the power to last this long going at a speed of 20-40 km/s.