Fusion Rockets and Missiles

A thread of 7 messages, 3 June 1993 to 5 June 1993, in the order they were sent.

#5552 Fusion Rockets and Missiles

Thruster plates are dead.

Fusion Rockets are in.

Well Ladies and Gents, you all outta know what that means.  The
only kind of sensor you'll need to detect these ships is the Mark-I
eyeball.  Fusion rockets are going to be blindingly bright.  You
will NOT need advanced sensors to find your targets.  And there is
almost NO possibility of using decoys.

As a sence of scale, let me point out that the lowest performance
engines here are those of the type S scout ship or the old type A
free trader.  These engines have about 1300 tons of thrust.  What
earthly rocket engines compare?  Well, that's about half as much
thrust as NASA's Saturn V (First stage) launch vehicle which took
the Astronauts to the moon.

I seem to recall a description of the Saturn V lift off as being
along the lines of "The Saturn V didn't lift off:  Cape Kennedy
Sank!"

I think Bertil & Wildstar are getting Far more complicated and
expensive than they have to with their missile seeker heads.
Passive is THE way to go.

Decoys will NOT be practical.  In order to copy the IR signature
you will need something as bright as a Saturn V.  In order to copy
the plasma jet you will need something hotter than a Saturn V.  In
order to copy the mass signature, you'll need some weird grav
equipment.  In order to copy the neutrino signature, you will need
a fusion reactor.

The only practical decoy that could copy the signature of a ship
well enough to fool the sensors and missile programming is...
another SHIP!

Ok, what counter measures can you pull against a missile with a
totally passive seeker head?

Well, you would have to turn to face it head on.  Using the bulk of
the ship to shield it's own engine emmissions.  This maneuver will
be almost completely impossible due to the closing vectors.  Also
you would have to know the precise location of the missile (at
which point you may as well shoot at it).  Furthermore, it will
only protect you from one missile.  If there is more than one
missile coming at you and they are in communication with each
other, it will fail.  Flying into the sun will present similar
problems.  The vectors almost certainly won't add and a bit of
programming should allow the head to distinguish between a ship and
a star.  Thus all you will need is a passive IR head.

Ok, what if he cuts his engines at a critical moment and causes the
missile to loose it's lock?  Well, a ship that is not maneuvering
is an easily found ship.  You already saw it's last vector!
KaBoom!

All right, now that you have this baby closing in, what do you
need?  A proximity fuse.  Well, you can use a densiometer to do
that if the IR has gone off line.  I'd prefer to avoid using an
active radar as a fuse.  It would make the missile easier to find,
and it can be fooled by a chaff cloud (Sand Caster).

In my opinion, a totally passive head will be VERY effective
against TNE Ships.  IR, Neutrino, Densiometer combination will be
EXTREMELY hard to beat.  Furthermore, the Neutrino and Densiometer
are just icing on the cake.  The main component needed is that IR
head.  And remember, that's just a plain old TL6 seeker.  We are
talking about a heavy version of the AIM-9 Sidewinder here!

Also, Bertil mentioned the idea of rolling bombs off the loading
bay manually to attack undefended targets.  Why get so complicated?
Strapped to the back end of your ship is the biggest bad-assed
version of a fusion gun you ever imagined.  We are talking about a
fusion gun that has a back blast like a SATURN V for heavens sake!

Scott 2G Kellogg

#5555 More Missiles

[email removed] (Scott S. Kellogg) writes:

> Thruster plates are dead.
> Fusion Rockets are in.
> Well Ladies and Gents, you all outta know what that means.  The
> only kind of sensor you'll need to detect these ships is the Mark-I
> eyeball.  [etc.]

True enough, although to detect one at any range, you will need an
increasingly large telescope.  Those range bands are *big*!  For a sense
of scale, imagine trying to detect that Saturn V first stage with the
naked eye from the surface of the moon.

> I think Bertil & Wildstar are getting Far more complicated and
> expensive than they have to with their missile seeker heads.
> Passive is THE way to go.

I think that we're now assuming some unspecified form of autonomous
terminal homing; passive IR, Neutrino, or Densitometer are all possible.
Missiles will want long-range targetting information (particularly SIMs)
from the launching ship, so that the missile can be guided to the
correct target if there are several near the same bearing.

> Ok, what counter measures can you pull against a missile with a
> totally passive seeker head?

Well, you can shoot at it.  It probably has a fusion rocket for power,
too, and should be pretty darn obvious.  Lasers are the obvious choice,
but a Cannister missile should do a number on an enemy missile, too.
Delay detonation of the bursting charge until about 1.5s before impact;
this gives a 200m radius sphere with considerably more pellets per unit
volume.  1.5s doesn't give a 12G missile enough time to get out of the
way.

A small fission or fusion warhead should provide an adequate decoy,
depending on the exact technology of the seeker head.  The bomb could be
radiation-enhanced in the appropriate frequencies to better simulate the
ship's fusion exhaust.  This may not be a practical suggestion, however!
;)

Bertil Jonell [email removed] writes:
>   So there might be a niche for the HE as a cheap multipurpose missile (while
> the SFF is a better but more expensive multipurpose).

Great.  And I see that KEAP now becomes a cheap missile (if a little
difficult to hit with) that is more effective in ship-to-ship action
than a HE missile, and considerably cheaper than a HEAP or SFF missile.

>   Using a DU penetrator with a slenderness of 1:100 (normal today is 1:20)
> around 400kg, but that slenderness might be physically impossible (too slender
> and it will break instead of penetrating). With a slenderness of 1:20...
> twelve tons.  Yes, this might make a good excuse.

I think a 1:100 penetrator would be too slender; Uranium isn't a
particularly strong metal ... and it makes a decent reason for not
having a KEAPDU missile.

>   BTW: I think the Cannister and SFF missiles should be modified since their
> max damage is dependent on the penetration and it is limited in the same ways
> as that of the KEAP missile.

Sounds reasonable.

>   I think restricting MFD's to military ships is a better option. I'm reminded
> of the old starship combat discussion where I wanted there to be a major
> difference between military and civilian ships, and the MFD could be a way
> of doing this.

Good Idea!  MFDs at the current TL restricted to military vessels.
Authorized para-military outfits (like starmercs with good reputations)
could buy MFDs at a couple of TLs below the current military.  And a few
(*very few*) would appear on the black market (probably the same TLs or
slightly lower as the starmercs can get).

An unauthorized ship with a MFD installed, or with restricted weapons
onboard, could be subject to immediate impound, or even seziure, by the
authorities.  I like this.

>   Argh! I misinterpreted the 'Friendly Velocity' formula on page 324.

Haven't read that part yet.  What do you think of the space combat
movement changes?


[email removed]
- --------------------------------------------------------------------------
                                                 Science-Fiction Adventure
                                                            in the New Era

#5556 Re: More Missiles

Wildstar Sagt:

> > only kind of sensor you'll need to detect these ships is the Mark-I
> > eyeball.  [etc.]
>
> True enough, although to detect one at any range, you will need an
> increasingly large telescope.  Those range bands are *big*!  For a sense
> of scale, imagine trying to detect that Saturn V first stage with the
> naked eye from the surface of the moon.

Ok, so I exaggerated a bit.  But remember, from Earth to the Moon is
15 range bands or so.  So we're both exaggerating.

> > Ok, what counter measures can you pull against a missile with a
> > totally passive seeker head?
>
> Well, you can shoot at it.  It probably has a fusion rocket for power,
> too, and should be pretty darn obvious.  Lasers are the obvious choice,
[etc]

True.  But those options work just as well against an active missile
or a command guided variety.

> A small fission or fusion warhead should provide an adequate decoy,
> depending on the exact technology of the seeker head.  The bomb could be
> radiation-enhanced in the appropriate frequencies to better simulate the
> ship's fusion exhaust.  This may not be a practical suggestion, however!
> ;)

Practicality aside, I don't think it would work.  How long does a nuclear
warhead last?  If it Could simulate the target ship's signature, it
wouldn't do it for long!  :-)

Scott 2G Kellogg

#5566 Re: More Missiles

> >   Argh! I misinterpreted the 'Friendly Velocity' formula on page 324.
>
> Haven't read that part yet.  What do you think of the space combat
> movement changes?

  They sound logical. If the opportunity occurs, I'll try them out this Sunday.

  Addenda on missiles:

  A missile launcher on any ship that hasn't been purpose built to have a
missile launcher on that specific hardpoint (like the patrol cruiser) will
probably have to be reloaded from *outside* the ship. If we assume that same
density of the starship missiles as of the tac missiles (1) the missiles
will be 7 cubic meters big. That probably translates to something a little
over a meter in diameter and 7 meters long. That comparable to a extended
range Standard Missile, and considerably thicker.
  There is no way you can maneuver this monster around in a scout ship, so
the launcher has to be reloaded from the outside when the ship is not in
combat.

> [email removed]

- -bertil-
- --
"It can be shown that for any nutty theory, beyond-the-fringe political view or
 strange religion there exists a proponent on the Net. The proof is left as an
 exercise for your kill-file."

#5572 Re: Fusion Rockets and Missiles

Bertil Sez:

[Maneuvering ships will be easy to detect]

>   If they burn all the time, yes. But considering the low endurances I suspect
> that most ships will coast along most of the time.

Yes.  They will coast.  But during combat you will most likely be trying
to maneuver in some fashion.

>   If you are close to a planet, the ship can either run its CG lifters, or
> not, or run them at fractional power. That will change its vector without
> any active emissions.

Contra Grav lifters should be detectable by fairly low tech densiometers.

>   In old Mayday you got a 1 light second/100 minutes vector when you passed
> within 1 light second from a planet. Differences enough to make a difference
> for combat purposes are (if Mayday is correct) available futher out.

A missile built for space ought to take gravitational wells into account
in it's programming.

> > All right, now that you have this baby closing in, what do you
> > need?  A proximity fuse.  Well, you can use a densiometer to do
> > that if the IR has gone off line.  I'd prefer to avoid using an
> > active radar as a fuse.  It would make the missile easier to find,
> > and it can be fooled by a chaff cloud (Sand Caster).
>
>   The trouble is that densitometers with that range might be rarer, more
> expensive and more hightech in TNE. The same holds for neutrino sensors,
> so that leaves active proximity fuses.

Well, they were bloody cheap in Trav.  1000 Cr for a densiometer, and
1000 Cr for a neutrino sensor.  (JTAS 21 Missile Suppliment)

> > Also, Bertil mentioned the idea of rolling bombs off the loading
> > bay manually to attack undefended targets.  Why get so complicated?
> > Strapped to the back end of your ship is the biggest bad-assed
> > version of a fusion gun you ever imagined.  We are talking about a
> > fusion gun that has a back blast like a SATURN V for heavens sake!
>
>   Undefended is relative. If you go low enough to use the drives, even
> Captain Hornblower with his TL3 Naval Gun could put a lucky shot in your
> thin-hulled ship. If you stay on 3000m and use laser guided bombs you are
> out of his reach.

Actually, not many TL3 Naval guns could elevate that well...  But my
guess is that the plasma plume of the engines is going to be equivalent
to a HEAVY fusion gun with a range of several kilometers.  If it isn't
then I'd imagine a bit of fooling with the drives could make it at LEAST
as effective as an FGMP-15 or so...  And don't forget:  The old FGMP
had about as much firepower as a 12"  High velocity naval gun...  :-)
- --
Scott 2G Kellogg
"I have some people I have to slam in this song"  -- Metlay

#5573 Re: Fusion Rockets and Missiles

> >   In old Mayday you got a 1 light second/100 minutes vector when you passed
> > within 1 light second from a planet. Differences enough to make a difference
> > for combat purposes are (if Mayday is correct) available futher out.
>
> A missile built for space ought to take gravitational wells into account
> in it's programming.

  What I ment was that the ship, by varying the CG (there already is a
detectable gravitation fiddling inside it: the inertial compensators and
artificial gravitation) against the gravitation of a large body could vary
its vector in an undetectable way.

> Well, they were bloody cheap in Trav.  1000 Cr for a densiometer, and
> 1000 Cr for a neutrino sensor.  (JTAS 21 Missile Suppliment)

  Well, missiles were cheaper then:)

> Actually, not many TL3 Naval guns could elevate that well...  But my
> guess is that the plasma plume of the engines is going to be equivalent
> to a HEAVY fusion gun with a range of several kilometers.

  Remember that the new fusion and plasma rifles have a range of up to 70m,
and they use a laser to prep the way of the plasma bolt. Without the laser
'the plasma bolt dissipates far too quickly'.

> Scott 2G Kellogg

- -bertil-
- --
"It can be shown that for any nutty theory, beyond-the-fringe political view or
 strange religion there exists a proponent on the Net. The proof is left as an
 exercise for your kill-file."

#5578 Re: Fusion Rockets and Missiles

Bertil Jonell (BJ>) and Scott Kellog (SK>) discuss the relative merits of
navigating close to a planet to avoid missiles.

BJ>   If you are close to a planet, the ship can either run its CG lifters, or
BJ> not, or run them at fractional power. That will change its vector without
BJ> any active emissions.

SK> Contra Grav lifters should be detectable by fairly low tech densiometers.
[...]
SK> A missile built for space ought to take gravitational wells into account
SK> in it's programming.

BJ> What I meant was that the ship, by varying the CG (there already is a
BJ> detectable gravitation fiddling inside it: the inertial compensators and
BJ> artificial gravitation) against the gravitation of a large body could vary
BJ> its vector in an undetectable way.

I kind of like this; this means that most serious battles will take
place around planets, which makes a lot of sense.  The problem with
space is that it's too bloody large and empty.  I have a really hard
time seeing any two ships getting together for a fight unless they
*both* maneuver to meet, or one side has an immense advantage in speed
and maneuverability.  This means that the preliminary to combat would
be maneuvering to gain advantage of position around a planet, which
also happens to be the best place to have a chance of avoiding attacks
- -- otherwise you get a mutual kill.

Note that the impossibility of avoiding a missile works against the
missile - since the missile itself can be tracked and defeated with
lasers or counter-missiles in much the same way.  I would imagine
technologies would be developed to take advantage of this.

There's also the potential for coasting missiles; the missiles would
go "dead" for a large part of their flight and hope to avoid detection
until they go active close enough to (hopefully) get in before
defenses could defeat them.  If this tactic were extended to ships, I
imagine space battles would look much like submarine combat...

In reference to detecting contragravity, I suspect that stealth
contragravity technologies would be developed; technologies to hide or
disguise the detectable emissions.

Steven J. Owens
[email removed]