Raytheon AGM-289 Coral Snake
Notes: For some
reason, this did not occur to me until years after I came up with the R-5D
Aurora hypersonic reconnaissance/strike aircraft: If the R-5D was going to be
conducting a surprise nuclear strike against a North Korean division in the
Twilight War, it would need to have an even faster weapon to fire to conduct
that strike. That is the reason for this entry – something for the R-5D to use
in its strike, and potentially planned for other strikes.
Thus, the Coral Snake ASM.
Twilight 2000
Notes: As war clouds loomed over the world in the early 1990s, it was thought
that the Aurora aircraft could, with its modularity, be repurposed on occasion
as a strike aircraft for use against strategic targets where conventional
bombers or strategic missiles would not be appropriate or advisable.
In addition, the Aurora could also be used to strike targets where
further a rapid response time would be needed and pinpoint accuracy would be
warranted. However, no such weapon
was at that time in the US inventory. In January of 1993, Raytheon was secretly
contracted by DARPA and the US Air Force to come up with such a weapon.
The new weapon would need to be even faster than the Mach 5+ the R-5D was
capable of, have a range enough to keep the R-5D reasonably out of danger, and
be able to carry enough of a warhead to make the strike worth it.
Ideally, it would also need to be capable of bunker busting, able to
penetrate through up to 25 meters of reinforced concreate and earth with a
conventional warhead, or carry a decent throw weight of nuclear warhead.
Raytheon felt that this was too much for the DoD to ask, but gave it
their best shot, with excellent results, producing the AGM-289 in record time
for such a weapon – the XAGM-289 prototypes were flying by July of 1995, with
LRIP (there was never any full-rate production) beginning about a year later.
The prototypes were noted for their elaborate paint schemes, reflecting
the color pattern of the snake from which their name is drawn.
Raytheon began
with a modified Phoenix missile, but quickly found that the Phoenix’s airframe,
intended for use as an air-to-air missile, could not carry a large enough
warhead for the task. Raytheon then
enlarged the Phoenix, increasing its size by over 50%.
This also allowed for the fitting of a new high-impulse rocket motor
which accelerated the Coral Snake to Mach 7 in less than a minute when dropped
from a Mach 5-flying Aurora aircraft.
The high speed allowed the Coral Snake a satisfyingly long range when
fired from an R-5D at speed. (Attempts to mate the Coral Snake with other
aircraft, such as the B-52, B-1 and B-2 did not lead to as dramatic results,
with the AGM-289 able to accelerate to only Mach 4.5 when fired from such an
aircraft, and the AGM-289 became an Aurora-only weapon until late in the War.)
As the airfoils were not enough to give the missile enough control in
flight, thrusters were added near the tail to give the missile more control
authority.
The carriage of
an AGM-289 required a slight modification to the R-5D’s weapon bays due to the
weapon’s large size and the need to kick the missile into the slipstream and
away from the aircraft quickly. In
addition, the use of Coral Snakes required the replacement of some of the R-5D’s
reconnaissance fit with fire control avionics.
Warheads
initially tested were conventional, and primarily HE warheads with nose of the
missile tipped by a thick tungsten cap for additional penetration.
These proved to be effective enough to meet and even exceed the original
DoD specifications for penetration.
Initial guidance was to be by GPS, but as satellites began to fall, inertial
positioning was fitted with a TERCOM kicker.
This of course required the pilot of the Aurora to fix the position of
the target and link it to the AGM-289 before launch, something which required
about 15 seconds of minimal maneuvering.
However, a nuclear warhead was always considered for the Coral Snake, and
one modified from that of the B-61 bomb was fitted onto six Coral Snakes.
Perhaps the best
known, and most controversial, use of a Coral Snake from an Aurora aircraft was
the November 1997 nuclear strike on a North Korean division that was closing in
on Allied forces in North Korea.
The strike was until the 2030s known as “the nuclear strike from nowhere”, as no
side had any launch indications from any weapon system or aircraft carrying a
nuclear warhead in theater, and no one was going to send a relatively inaccurate
missile from out of theater.
Nonetheless, the Coral Snake scored an almost center-mass bullseye on the North
Korean division in question, with a warhead programmed for 100 kilotons of
yield. This saved the Allied
Forces’ bacon for a while, but the use of a tremendously expensive and
irreplaceable asset like an R-5D was discussed among military leaders until it
didn’t matter anymore.
Weapon |
Difficulty |
Guidance |
Weight |
Price |
AGM-289A |
Easy |
Inertial/TERCOM |
715 kg |
$209560 |
AGM-289B |
Easy |
Inertial/TERCOM |
715 kg |
$479560 |
AGM-289C |
Easy |
Inertial/TERCOM |
715 kg |
$20956000 |
Speed* |
Round |
Min Range |
Max Range |
Damage |
Pen |
|
AGM-289A |
12741/7645 |
KEP/HE |
3400 |
273300 |
C452 B215 |
695 |
AGM-289B |
12741/7645 |
KEP/Thermobaric |
3400 |
273300 |
C565 B162 |
695 |
AGM-289C |
12741/7645 |
Variable Yield Thermonuclear |
3400 |
273300 |
40-150 kt |
695 |
*The
speed is when fired from an R-5D at speed/subsonic launch.