Missiles and Drives and Such

[email removed] (Leonard Erickson) writes:
> I can just about *guarantee* that detonating velocity is *far* below
> closing velocity. Which means that shaped charges are useles, as the
> missile impact will be moving faster than the detonation of the
> explosive. This kills HEAP and doesn't  help HE much either.

I'm afraid that I'm no expert on explosives, but presumably the timing
of the detonation can be arranged to work out anyway.  The penetration
mechanism of a HEAP charge is the jet of hot gas generated.  To make it
work at high speeds, you need to have a proximity fuse that will set off
the warhead the right amount of time before impact, right?

> And I'm willing to bet that velocity #2 is below closing velocity in
> most cases as well. Which again makes HE a waste of time!

Not quite.  KEAP is kind of useless agains a ground target - it has lots
of energy, but doesn't deliver it in the most useful form.  So HE will
be around as a ground attach missile that just happens to have a
secondary anti-ship role.

And as Bertil points out, you can always choose *not* to detonate the
explosive, after all - it's still got it's kinetic energy.

[email removed] (Steve Higginbotham) writes:
>  Your reasoning is specious, as can be seen by
> looking at pictures of any Saturn launch.  The blast punches DOWN!
> Hard!  Way too hard for anything trivial like atmosphere to slow it
> down.  It only takes about 0.0025 seconds for the blast to reach from
> 50,000 meters to ground level.  Even at mind-boggling pressures, it
> isn't going to spread much till it hits ground ("not much" means that it
> should still be focused on an area no more than 10Km across...).

The Saturn had some pretty darn big flame trenches to contain that blast
and make sure it doesn't interfere with the rocket.  Do *you* really
want to land in the middle of a 10km wide area that's been under fusion
gun attack for the last however long?  And how are you going to get the
landing legs of your starship unstuck from all of that fused soil?  All
concerns of player characters torching cities aside, I don't think you
want to have to land in that stuff, no matter whether or not there is a
local authority to tell you not to.

> Probably use Scramjets, just like we used to do back in original Trav
> when we first started playing many years ago...

One of my proposals (which didn't seem to make it to TML) was to open
some ramscoops and admit air into the fusion rocket chamber.  Heat it to
very high tempratures (possibly with the fusion ignition system) using
power plant energy, and let it expand out the back.  Similar in concept
to the US "Pluton" missile propulsion system (the Pluton used a fission
reactor operating literally a few degrees below it's meltdown temprature
as a heat source).  It wouldn't provide anywhere near the thrust of a
fusion rocket, but it should be enough to maneuver the ship with.

The other proposal was to use the CG lifters to control the aparrent
weight of your vehicle, and literally glide down (or up).  Use
aerodynamic control surfaces to provide control and lift.  This provides
a rationalization for why only streamlined and airframe ships can
operate in an atmosphere (you need to be sufficiently streamlined to be
aerodynamically stable, and you need some control surfaces).

> DREAM ON, Bertil!  Look at a REAL rocket launch!  MUCH lower exhaust
> velocity, MUCH lower pressures, and they DO _NOT_ form fireballs - they
> form long tongues af flame.  Which this will do as well.  Only this will
> make them longer, hotter, FAR more lethal!

I have seen plenty of real rockets get their tailfeathers scortched by
launching from a pad that had a poor blast deflector design.  For the
rockets I'm talking about, the problem is minor and can be repaired with
a little paint and filler putty.  I doubt that your PC's starship is as
easily repaired when damaged by stray fusion exhaust.

Go fly some real rockets and try different blast deflector designs.
I'll give you a clue: a flat plate is one of the worst offenders.
Something that is angled away from the rocket is much better.


[email removed]
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                                                 Science-Fiction Adventure
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