Physics seem to consider otherwise.
Physics matter very little when it comes to 'guidance', 'navigation', and 'control systems'. The issue here is the proper context of all of them.
The apogee for a medium range missile like the DF-21 is approximately 90 miles (based on apogees of respective Indian and Pakistani missiles). The terminal stage starts much lower than the apogee, but for the sake of this argument it'll suffice for now. The terminal velocity of the ballistic missile is approximately Mach 10. With that, the acceleration (reentry speed is already hypersonic for most missiles) and the altitude gives the ballistic missile a bit over 40 seconds to strike the target.
Here's a link:
http://www.plrc.org/docs/010824A.pdf
The link above says the terminal phase is about 30 seconds.
Hey, buddy...Read your own source. I asked for a credible third party source that explains how could a descending warhead maneuver and to what extent within a certain time frame. What you brought on was
NOT a technical source but essentially a rant against defense budgeting.
There are two methods to maneuver a moving body in a medium such as air (or water): reaction thrust or aerodynamic (or hydrodynamic) force exploitation. The former allude to rocketry. The latter to flight control surfaces. Which method is best and when? The higher the body's velocity through this medium the greater the force require to change its attitude, or slow it down, or redirect its forward motion. So at double digit Mach, the rocket thrust mechanism would be how large? Or how robust must the flight control surfaces be? That is what the readers are looking for.
Use your knowledge and explanations to disprove what I said earlier. Don't pull this "I'm more experienced" crap on me.
The physics behind free falling objects hasn't changed for the last century, mind you.
Absolutely I can. I have always support my arguments with credible third party sources and advise the readers to use keyword searches to verify what I said. More so than we can say for you Chinese boys. To date, not one of you have proved what I said is wrong. If anything, it is awfully hard, if not outright impossible to prove what I said is wrong when I present evidences that are applicable to everyone, including American stuff. I could not do that if I have no relevant experience.
Here is a clue for you...
Guidance is not the same as navigation. Control system is the third leg but usually if a system has navigation, it is given that the moving body has a control system so generally we who have relevant experience in this matter confine the discussion to just guidance and navigation. After all, without a control system, it is useless to install a navigation system.
Guidance is when you know the exact destination where you are going and just want to maintain a steady course. Guidance has no external correlative inputs.
Navigation is much much much more complex.
That will be all for now.