A direct hit no but that's never been the issue. Ground shock and overpressure hardening are required. No the "aim" is not to launch as soon as possible and never has been despite what Hollywood and fiction may tell you 
Especially when you get into multiple warheads on missiles because your targets will change a lot even during the initial launch. Since the policy is not to launch unless we are attacked you have to plan to take some hits before ANY of your birds are in the air. Why? Because SLBM's and other short range weapons are a thing and they will get to you likely before you can launch some of the closer sites. Considering how close some of those may be you need to ensure you missile can ride out the initial shock and THEN launch before more warheads hit.
Initial launch is usually generally planned to be about half to one-third of your force assuming it's not a first strike. (And by policy and outlook we don't really plan a first strike anyway. Mind you we HAVE a plan for such as do the Russian's, Chinese, Indians, etc, etc. But it's not very high on the decision tree) With updated info between that launch and first incoming strikes of the main wave you can adjust and get about another third out of the hole and outbound before main impact. US and NATO policy is to hold back a 'second wave' of weapons because we're well aware we won't get everything in the first round. Ours are mostly SLBM and Bomber based the former because of the higher survivability factor and the latter due to the time-to-target ratio. In any case if it looks like a full attack then you of course "launch for survival" and get everything into the air but you really want good targeting information first. In any case you'll have some problems and some birds may not get off before everything hits so it behooves you to be able to survive a near miss and save the bird.
Lastly of course is by having obviouse plans to and building to survive an incoming strike gives the enemy something to think about because, (and the reason it is called "MAD" in the first place) if he can't kill all yours then you can still kill him.
Very carefully Seriously, military motors are built like tanks with extra reinforcing and multiple redundent and robust systems, in many cases that a "commercial" motor wouldn't even have in the first place. Since a lot of this stuff isn't meant to be removed in the first place that will compromise the stage for military use but is still likely way over built for a commercial booster. The only reason the commercial's even use them is because they are 'cheap' but they are really terrible for the purpose.
Not at all actually because the Castor 120 is far to fragile and complex for use as a missile first stage. Add in the propellant combination isn't usable for a military missile, (it has a lousy shelf life, slowly destabilizing even in a controled environment and develops cracks within a couple of months) The basic tooling is from the Peacekeeper program but only a little of it is used. To turn a Castor 120 into a working missile stage you'd have to use a different propellant mix and process, (which they don't have anymore, the formula yes, but the mixers and slurry pour system was scrapped due to contamination), increase the casing thickness, set up new jigs and forms to allow placement of the systems I mentioned they tore out above and some of those have to have specially cast/constructed fittings and housings in the case. Additional rocket control housings for RCS and vector control for the main engines needs to be added back in.
Not really, HGV by it's nature needs to get back into the atmosphere as soon as possible so any decoy's are gone early on. You might put some decoy's and pen-aids on the vehicle itself but that increases the size and complexity which decreases survivabilty.
How so?
We're talking a regular warhead here keep in mind so exo-intercept is handled (we hope) by decoys and penetration aids. This was only for 'terminal' defense and you don't WANT EMP as it's not effective against military systems anyway.
You'd need an actual manueverable warhead and likley something with a really good L/D ratio.
Which was one reason the Soviets invested so much in orbital communications, sensor and radar satellites They REALLY didn't like the US Navy.
This actually since everything depends on how the HGV is designed, what it's designed to do and what the mission parameters are.
We tend to mix and match as the converstaion goes on
Maybe faster, but definatly will show up on radar sooner as they are higher above the horizon. The lower angle 'ballistic' trajectory isn't a low-energy trajectory it's a high-energy 'powered' trajectory specifically to keep the warhead lower than a standard trajectory. The 'depressed trajectory' profile is even less efficent but moves the free-flight (ballistic) path even lower so as to reduce the warning time even more.
I've been looking at this stuff online and from what I can tell Direct Injection isn't really seen as a good option since it requires the entire upper-stage/bus assebly be not only able to accellerate through the atmosphere but be able to seperate the HGV while there which is 'challenging' to say the least. (Essentially the 'bus' and upper stage have to be an HGV for it to work at all and likely the actual HGV is the 'nose' of the vehicle. The problem with this is the modifications to allow the booster/missile to do this are significant enough that it becomes only usable for the HGV mission. Keeping a lot of the accelleration outside the atmosphere is rated as far better) So the main plan seems to be a depressed trajectory outside the atmosphere to upper stage cut off, usually at a negative angle and high thrust to push the HGV into the atmosphere so it can manuever and give it the highest "starting' velocity, followed by an extended hypersonic glide with steadily lowering altitude as atmospheric effect allow.
The "decoys" would have to be HGV's themselves for that to have any chance of working. It's the same problem with 'light' decoys and standard warheads, they don't behave at ALL like the real thing in the environment unless they ARE the real thing.
Matching them tit-for-tat is a loosing game since we're already behind, but we need to keep somewhat even to stay in the game at all. Hence building what we can with what we have and then looking to push ahead as soon as possible. Trying to leap ahead at this point isn't really viable given where we're lacking in progress. We do know however how to get the most out of what we have and can field in a timely manner. Past that it's getting back into the mindset, (and spending habits which is going to be the hard part because that includes TAXING habits that are not going to be plesant at all) of facing peer adversaries instead of planning on being able to "Shock-n-Awe" the bad guys into submission.
It's going to go VERY far past just a new ICBM too and we'll have to make that decision real soon too.
Randy
