How quick to develop/field space warships?

In the background of my Pax Martiana game, there are:

regular robot shipments of LOX/LH2 fuel into Earth orbit
manned stations on/over Mars
manned stations over Earth, Mars, and Venus
civilian manned and unmanned spacecraft supporting these stations

Not long before that start of the game, the first space warships are
commissioned specifically to blockade Earth from incoming spacecraft by the USA.

How quickly could this be done? You can assume:

There's a moderate sense of urgency. The new administration wants to field
something in Earth orbit within 18 months, before the mid-term elections.

The USAF has been itching for an excuse for space warships for years, and
eagerly dusts off some sketchy paper studies. Most of these emphasize pure
laser armament, but pure laser armament is rejected mainly due to the influence
of aerospace lobbyists.

There are some off-the-shelf naval ABM/ASAT missile systems, albeit never used
in combat. These require the integrated naval radar systems. Aerial sensor
systems lack the required range; space sensor systems lack the required
resolution (they lack cooperative trilateration capability).

There are mature laser weapons already fielded and used in terrestrial combat.
These are particularly important for anti-aircraft work since they don't have to
fight gravity/drag like SAMs and they're cost effective to use against small
UCAVs.

There are some interservice rivalry issues, as USN personnel will be lent to the
USAF to support the radar/missile systems in the field. The Navy sees these
space warships as little more than dumb rockets used to haul Navy hardware into
the battlefield. But they can't wrest rocket ships from the USAF unless the
boosters are sea launched (ala Sea Dragon). The USAF wants to immediately start
development of "native" space missile systems, so they don't have any more navy
hardware foisted upon them. The USN wants to revive Sea Dragon so they can shut
out the USAF altogether.

The basic idea will be to put together a "minor" modification to a civilian ship
design, slapping on off-the-shelf naval ABM radar/missiles and commodity lasers.

However, see the stories of the M247 Sergeant York DIVAD and various criticisms
of NASA's Constellation program for cautionary tales about trying to slap
together "minor" modifications to off-the-shelf technology.

I'm guessing, based on typical development times for modern aircraft/ships, that
this development could take several years...but there's pressure to field
something faster than that.

Conversely, the Martians will be literally slapping weapons and armor onto
civilian ships (think Confederate ironclads). They don't have the time or
resources to figure out precision terminal guidance capability, so they'll just
have to live with civilian grade guidance precision. This will turn out not to
be a big disadvantage, since smoke/chaff create significant uncertainty zones
anyway, and because enemy missiles have grossly excessive mass ratios (due to
the original surface launch requirements).

Some hardware can be economically smuggled to the Martians before the
blockade--preferably civilian hardware, though. Rocket thrusters and controller
hardware are good. Military radar and ABM/ASAT missiles are too big/heavy and
too traceable. Lasers may be too big/heavy but they are less traceable.

In gameplay terms, I'm hoping to remove the strategic decisions of production
away from the players, to simplify playability. This simplifies the game from a
strategic/operational/tactical game down to operation/tactical. Production is
simply a matter of new "stuff" becoming available. The strategic level becomes
purely a matter of logistics, and those logistical decisions are plenty rich
enough already. You have to decide if/when to launch your Jovian tankers to
Earth or Mars...realizing it takes 3 years for them to arrive. Will you have
control over that space in that time? How will this affect the decisions of the
enemy? Conversely, will your forces have resupply when they need it?

But I still need an idea of what the design loop will be like for new designs.
Wartime can accelerate R&D, or it can retard R&D. Both the USA and Mars
sympathizers will be doing R&D on Earth, so better hardware may become available
to the players with time.

Thanks!

Isaac Kuo mechdan@...