Find the Speed of Each Rocket

Two test rockets are fired over a 5600-mile range. One rocket travels twice the speed of the other. The faster rocket covers the distance in two hours less time than the slower. Find the speed of each rocket.

I cannot formulate the equation for solving the above word problem, even after 2 pages of paper and more than a few of hours of attempting. Can someone give me a hint please, and/or even better, point me to an appropriate lesson(s)/article(s)!

I can understand that since rocket 1 is as twice as fast as rocket 2, and since rocket 2 arrives at the destination 2 hours later than rocket 1, that, (I think, anyway)

                               Distance = 5600 miles
Rocket 1                                               Rocket 2
Time = 2 hours                                      Time = 4 hours
Rate must = 2800 mph                           Rate must = 1400 mph

As I can guess the above, so to speak, however, what I cannot "see" or formulate is the equation for solving this problem (if I "guessed" it correctly). Is it possible to solve this problem using a quadratic equation?

This problem is in the chapter "Solving Equations - First Degree and Quadratic" of a Elementary Algebra book (30+ years old), and the chapter does not have the answer or the process for a solution to this particular type of problem, for whatever reason. I suspecting this is more of a "system of two equations in two unknowns" type of problem, which I have not yet studied (getting there).

Not working through this book for school or work, just trying to further (or reacquire) my education in my spare time (what little I have, even with the kids gone now) for personal reasons!

Any help will be really appreciated!
Thanks!