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- From: ssi!lfa@uunet.UU.NET ("Louis F. Adornato")
- Subject: Re: Railgun in Southwest US
- Message-ID: <C0HtJ3.Lqo.1@cs.cmu.edu>
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- Distribution: sci
- Date: Thu, 7 Jan 1993 16:47:16 GMT
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-
- uunet!eros.calpoly.edu!jgreen writes:
- > I've heard a rumor that some organization (SSI?) has actually
- ^^^^<--- (see signature line)
- > built a large railgun somewhere in the SW USA. It's apparently
- > supposed to be big enough to put small payloads (>5 kg) into
- > orbit, though I don't know if they've done that yet.
- >
- > Is this a rumor or is there some truth to it?
-
- I can state with some certainty that it wasn't us.
-
- Seriously, I saw a public demonstration of a rail gun on the tube a few
- years back, but it was intended as an onorbit weapon for SDIO (this
- whas when they where fighting their "No, we're really not a pipe dream"
- funding battle). I think this was in So. California, which is
- certainly SW USA. As I recall, it fired something about the size and
- shape of a hockey puck (there's that Canadian influence again, eh
- Henry?). I haven't heard anything about a ground based version.
-
- Personally, I don't know that a railgun is going to be worth much for
- anything other than ASAT and ABM applications. The problem is that a
- ground launched body can't attain orbit (at least, not an orbit that
- doesn't intersect the surface) without a circularizing burn at
- periapsis. This means that you have to carry propulsion (motor and
- fuel), GNC hardware (star trackers or a gyro/accelerometer platform,
- momentum wheels or an RCS, guidance computer and control hardware),
- power and cooling, a shroud capable of protecting the whole shebang
- when it exits the launcher in sea level air at better than 17,000 mph
- (orbital velocity at 150 mi), aerosurfaces to prevent tumbling, and
- probably active control of same, and still retain enough mass
- capability for a payload.
-
- On the other hand, if all you want to do is intercept incomming
- missiles, you can scrap most of this except the shroud and the
- aerosurfaces. Approriate sensor technology in the nose and a
- "bang-bang" control system for terminal homing, and you have enough
- payload space for a fuze and some plastique (although the entire
- vehicle becomes a warhead at the kind of intercept speeds involved).
- Of course, a rail launcher certainly wouldn't be portable, and the
- power generating equipment (if not the rail itself) would be pretty
- noticeable from orbit. Might as well put up a big sign that reads
- "Please Nuke Me".
-
- Seems to me that something like Pegasus is a better investment for both
- types of applications in this payload mass category.
-
- Lou Adornato | "Sure, the cow may have jumped over the
- Supercomputer Systems, Inc | moon, but she burned up on reentry"
- Eau Claire, WI | The secretary (and the rest of the company)
- uunet!ssi!lfa or lfa@ssi.com | have disavowed any knowledge of my actions.
-