I don't know!
I feel sure that others have already examined the possibilities? If you have the answers, please send them to us. email@example.com
I've looked all through the Internet, and I haven't found anyplace where the issue is examined. If there are such sites, please send them to us. It is possible that those countries that have examined the question have either struck out, or have kept the solution classified.
I do know that the easy answer is "NO, it can't be done." I've talked to people who made the calculations in college physics classes as an exercise, and the answer is NO, it can't be done. It would take all of the energy extant on earth to move the earth out of its orbit. The error in this exercise is considering the entire mass of the earth, and thinking of a single thruster site. We can consider many thruster sites. Changing the tilt, for example, would only require moving the crust around the mantle. Changing the ecliptic, spin rate or orientation takes only a fraction of the energy that it would take to change earth's orbit. We must also consider the probability that new forms and sources of energy will be discovered or invented in the future.
I have asked retired military people to explore whether the government has ever examined the question. I haven't had an answer. This means the US government has never explored the question, or I asked the wrong people, or it means that the answers are classified. If there are answers that are classified, please do your best to find a way to free them up for others to examine. We must do our best to avoid thruster wars.
In the initial proposed time line, I've started with the assumption that for the first twenty years, we'll collect all of the various calculations that prove that thrusters can't change the earth's spin rate, tilt, ecliptic, orientation or orbit.
I assume (without any basis at all) that in the second 20 years we'll start getting possible solutions to the challenge. In the second 20 years of the time line, those that think it can be done will be debating with those who think it can't be done. So, unless it's easier than I think, or our scientists and rocket science students solve the problem more quickly than I predict, I figure within 40 years, we'll have a scientific consensus on how it could be done.
We'll post all of the various inputs on this site as they come in.
As I understand the problem, it is fairly easy to prove that it can't be done. We will post all of those proofs as they come in.
The more interesting question, one that I hope many teams of engineering students, or rocket scientists, or engineering faculties at Universities around the world, decide to work on, is "If it could be done, how could we do it?"
I expect many approaches will be explored. I have no idea whether it would take 12 huge thrusters, using huge bursts of thrust, or 1,000 small thrusters, using continuous thrust.
I do think that it is important to find an answer, if there is one.
Until we do, we are helpless in the face of global warming, ice ages, asteroid collisions, or even extinction level events.