Aircraft carriers...IN SPAAAAACE!

Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take. I've
seen "space battleships", relying on one or more "big guns" installed
directly on the ship, and "space aircraft carriers", launching
multiple weapons platforms. (Fighters, gunboats, etc.) I've seen
both manned and unmanned motherships, and manned and unmanned weapons
platforms.

Which option do you all think is more likely?

On Aug 17, 3:40 pm, Damien Valentine wrote:

Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take. I've
seen "space battleships", relying on one or more "big guns" installed
directly on the ship, and "space aircraft carriers", launching
multiple weapons platforms. (Fighters, gunboats, etc.) I've seen
both manned and unmanned motherships, and manned and unmanned weapons
platforms.

Which option do you all think is more likely?

Both.

To me, the most likely possibility is "space battleships" which are
also "space aircraft carriers". These ships have powerful x-ray
lasers, but those lasers need to be aimed at a far away zone plate
lens in order to fire upon an enemy target at long range. For
example, the laser ship could be 30,000km away from the lens
drone, which is 100 light seconds away from the target.

In a sense, this is a "space battleship". While 30,000km sounds
like a long distance, it's actually only 1/1000 of the distance to
the target. Thus, the ship/drone pair essentially operates as a
single unit, lobbing photon salvos at the enemy.

On the other hand, the lasership is pretty useless on its own.
Without the lens drones, its laser only has an effective range
of maybe 100km--practically nothing. It needs to work in
concert with at least one lens drone. More plausibly, there
will be many inexpensive lightweight lens drones for each
lasership. Thus, on a "small scale", this team operates like
a big carrier escorted by a bunch of little fighters.

Isaac Kuo

On 17 Ago, 22:40, Damien Valentine wrote:
Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take. I've
seen "space battleships", relying on one or more "big guns" installed
directly on the ship, and "space aircraft carriers", launching
multiple weapons platforms. (Fighters, gunboats, etc.) I've seen
both manned and unmanned motherships, and manned and unmanned weapons
platforms.

Which option do you all think is more likely?

I try.

3 kinds of objects:

1) manned
2) unmanned reusable
3) unanned expendable (eg. missiles, bombs, shells but also suicide
crafts etc.).

The border between 2) and 3) is blended and some crafts could be
manned just in some phases of the trip or of the battle.

Unmanned crafts have less limits for g forces, no needs of vital
support so they have better performances and the cost(risk)/benefit
ratio is more favourable, so they are "more" expendable.

Apart ethics, building a craft in an autmated factory on some asteroid
is much less expensive and take less time than grow, educate and train
a child in a controlled environment (even an alien child). You have
to provide life support, gravity, food etc. for all his life. Mass
production of an enormous quantity of robotic aircrafts, instead,
require much less time and constrains.

On the other side you need some manned crafts at a decent distance
from the battle (eg. less than 1 light second) to take decisions in
time.

How much of them depends on how robotics and AI is advanced.

Providing that humans are required to take decisions.

I can't exclude that a 100% robotic long range attack is so effective
that it's the best option.

But even in this case maybe you simply can't keep the people at home,
because home is an easy target.
Maybe in case of space war the planets will be destroyed immediately
and people will be forced to hide in the space on an infinite number
of asteroids, platforms and crafts. If they know you are there, you
are dead, so you just have to hide.... like in the past people had to
flee from the cities and hide on the mountains.

Long range communication is essential, including ways to encrypt,
modulate and transmit informations so that enemy intelligence can't
capture it or even understand that this is a message and not noise.
Very directional information transmissions (eg. lasers) could help,
but this involves that if somebody has lost contact... he is lost,
except he do an omnidirectional transmissions and risk to reveal his
position.

As unmanned veicles are so many, another possibile strategy is to hide
people in some of them. The enemy don't know wich are the manned
veicles and they can't shot all of them.

It may be possible to figure where humans are tracking the veichels
that have a flight path incompatible with human life (eg. too much g
force, too much time in space). But this take time and you'll make
even unmanned veichles stay below the g limit.

Anyway I repeat that I don't think any planet or big artificial
environments can survive a first strike attack. Nuclear terror will
not be over in the space age, and a warehead launced at 0.1% of the
speed of the light is simply impossible to intercept.

Missile shields simply won't work.

By the way, I think all of these concepts are valid yet or will be in
few years, even for wars on earth: no shields, nuclear terror are
familiar concepts, and robotic war will be very early.

Quite horrible, isn't it? :-)

In a certain sense this is good, because thanks all of these
deterrents a total space war will be very unlikely as total nuclear
war was.

The only difference is that it will be possible to hide and survive
for some....and this is not a small difference.

As usual, aplogize for my terrible english! :-)

On Aug 17, 1:40 pm, Damien Valentine wrote:

Which option do you all think is more likely?

Spacecraft based around offensive beams will likely follow the
"battleship" mode, with one very large laser. If the laser emits in
the visible, near IR, or near UV, expect it to also have a very large
mirror for focusing. The more powerful the laser and the larger the
mirror, the longer range the spacecraft has and the better it is at
picking off enemies before they can shoot back at it, and the longer
it has to zap incoming missiles. It is plausible that many or all
war spacecraft will have defensive lasers that do not need to be so
large, with small beam pointer telescopes that can rapidly slew to
track incoming missiles. Likewise, the offensive beam craft may have
several smaller beam pointers to deal with incoming threats that get
too close, but it still only needs one laser.

Beam craft that emit VUV, EUV, or x-ray beams will likely need to turn
their entire bulk to face their targets, since mirrors don't work well
(or at all) at these wavelengths. They will still likely be built
around one very large laser, for the same reasons. If the laser is an
FEL, it is quite plausible that adding a second wiggler in the optical
regions of the spectrum is a minor expense while using the same linac,
allowing rapidly slewing point defense beam pointers as well.

Spacecraft built around kinetics are likely to be more like carriers.
I can see them launching drone "fighters" with high exhaust velocity,
low acceleration plasma drives to intercept targets, releasing a swarm
of high acceleration chemfuel seeker missiles when they get close
enough. The drone fighters are likely no larger than is needed for
one compact nuclear reactor, a plasma drive, adequate comms and
sensors, plus the "shotgun" of seeker missiles.

Luke

Which option do you all think is more likely?


Something that looks like the Saturn moon Mimas... :-)

On Aug 17, 2:52 pm, wrote:

Unmanned crafts have less limits for g forces

For realistic space drives, g forces will not be large enough to be a
problem. Indeed, the problem may be that they are too small. When
your main source of propulsion is an ion of plasma drive that scoots
you along at a milligee or so, you will not pass out from the
acceleration, but spending too long under those minuscule "gravities"
can lead to bone demineralization, a weak cardiovacsular system,
muscle degradation, and a host of other medical problems. Since there
are no realistic continuous high acceleration drives, manned
spacecraft will likely need large centrifuges or spin habitats to keep
their crew healthy.


But even in this case maybe you simply can't keep the people at home,
because home is an easy target.

It is plausible that planets are vastly easier to defend than to
attack. They have huge heat sinks for their power generators and beam
weapons, and can hide the location of their anti-satellite, anti-
missile missiles in a way that is impossible for space forces.

Maybe in case of space war the planets will be destroyed immediately
and people will be forced to hide in the space on an infinite number
of asteroids, platforms and crafts.

How do you plan to destroy a planet? You can slag the cities, sure,
maybe with a lot of work completely mess up the biosphere, put planets
are very tough.

Anyway I repeat that I don't think any planet or big artificial
environments can survive a first strike attack. Nuclear terror will
not be over in the space age, and a warehead launced at 0.1% of the
speed of the light is simply impossible to intercept.

How do you plan to get projectiles launched at 0.1% light speed?
Incidentally, warheads at 0.1% light speed are not going to be
terribly effective against planets with atmospheres. You get about 10
kilotons per kg (so a 1 ton impactor would deliver 10 megatons), and
at these speeds the impactor will disintegrate and explode in the
upper atmosphere. Thus, you need the explosion large enough to bake
the ground from a detonation at high altitudes. A large, high speed
object such as this is very vulnerable against smaller interceptors,
which can simply position themselves in the big thing's path and use
its own speed to blast it when they collide. Such interceptors will
be much cheaper than the huge, fast planet smackers.

Missile shields simply won't work.

Why not? I see effective missile killing being a logical outgrowth of
modern military laser and missile guidance weapon programs.

Luke

Damien Valentine wrote:
Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take. I've
seen "space battleships", relying on one or more "big guns" installed
directly on the ship, and "space aircraft carriers", launching
multiple weapons platforms. (Fighters, gunboats, etc.) I've seen
both manned and unmanned motherships, and manned and unmanned weapons
platforms.

Which option do you all think is more likely?


In my opinion whatever it ends up being will be unmanned and under
autonomous computer control.
Could be a large weapons carrier with missiles or directed energy
weapons aboard, or a lot of smaller units, that either destroy targets
by physically colliding with them or firing some type of projectile or
directed energy at them.
Putting human crew aboard would add vastly to the weight, size, cost,
complexity, and vulnerability of it.
The MOL got canceled when it was realized that a unmanned
reconnaissance satellite of the same weight could do a far better job.
It'll be the same in this case.

Pat

Damien Valentine wrote:
Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take.

http://www.projectrho.com/rocket/rocket3t.html#shipgrid
http://www.projectrho.com/rocket/rocket3x.html

On Fri, 17 Aug 2007 20:40:50 -0000, Damien Valentine
wrote:

Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take. I've
seen "space battleships", relying on one or more "big guns" installed
directly on the ship, and "space aircraft carriers", launching
multiple weapons platforms. (Fighters, gunboats, etc.) I've seen
both manned and unmanned motherships, and manned and unmanned weapons
platforms.

Which option do you all think is more likely?

What's most likely are just plain missiles launched from the ground or
from orbital platforms.

Damien Valentine wrote:
Speculative and sci-fi authors often assume humanity will eventually
take a long-term interest in space, and develop military spacecraft.
But they don't agree on the form such spacecraft would take. I've
seen "space battleships", relying on one or more "big guns" installed
directly on the ship, and "space aircraft carriers", launching
multiple weapons platforms. (Fighters, gunboats, etc.) I've seen
both manned and unmanned motherships, and manned and unmanned weapons
platforms.

Which option do you all think is more likely?

Depends entirely on the assumptions you make, what tech level you're
talking about etc. You can justify a fairly wide range of options.

Data point: a task force in the last spacefaring setting I came up with
(27th century), consisted of:

1 heavy cruiser of around 30,000 tons mass, with lasers and missile
racks and very heavy armor and shielding.
6 long-range interceptors, single human pilot, with guns (for use
against their counterpart craft) and missiles (heavy ship-killers with
nuclear warheads); loosely inspired by the Backfire supersonic bomber.

The interceptors didn't require a carrier, because the interstellar
drive system was a gravitic warp drive (loosely inspired by Alcubierre's
idea, with some handwaving about Higgs bosons and quantum gravity),
which also provided a lot of mid-range maneuverability in combat, so you
want it anyway, so the small craft automatically get independent
interstellar capability. They did have limited endurance, however, so
the cruiser served as a tender. (So not like TIE fighters, more like
beefed-up X-wings with intended endurance in days rather than hours.)

If I were going for pure realism (modulo the warp drive as a setting
premise), the cruiser would still be manned, but the interceptors would
be best-guess unmanned. An autopilot cannot be the subject of drama the
way a human pilot can, however, so I fiated even 27th century autopilots
to be less capable than humans at making split-second tactical decisions
in combat.

--
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