Over the decades a plethora of different
missiles were tested and some were
fielded with varying degrees of success. But today's defensive missile success
can ultimately be traced to the navy's
decision to neck down its missiles into
one family the standard missile. Like the overall aegis weapon system the
basic standard missile has been upgraded
during the past 30 years to keep pace
with evolving threats. The SM-1 the first version of the
standard entered production in 1967.
Designed to replace and improve upon the
navy's earlier tartar and terrier
surface-to-air missiles an improved
version of the SM-1 is still used by 11
foreign navies. The navy however needed faster reaction
times, longer range, greater jamming
resistance and more reliability in its
primary air defense missile. Building upon the SM-1 development of
the improved SM-2 began in the early
1970s.
Designed to function in a demanding
tactical environment the SM-2 models
feature an inertial mid-course guidance
package that receives command updates
from the shipboard fire control system. The introduction of the MK 41 VLS on Aegis warships and SM-2's
ability to accommodate modular upgrades
has allowed the missile to pace evolving
air threats and maintain its
effectiveness in difficult electronic
countermeasures ecm environments.
Block 2 was designed to have better
performance against high altitude, maneuvering threats. Block 3 improved missile performance
against very low altitude threats and
block IIA added enhanced interception
capabilities against sea skimming, higher
speed missiles and crossing missile
threats. The navy began the development of the SM-2 block IV in 1987. This variant
featured major enhancements in the areas
of guidance, target detection, altitude
velocity, jamming resistance and missile
control as well as a blast fragmentation
warhead.
Another aspect of the block iv design
was the thrust vector control booster
which gave aegis warships the ability to
engage extremely high altitude targets, a
key consideration in the navy's later
ballistic missile defense effort. The basic missile design was sound
however and in may 2006 a modified
version was successfully tested in the
sea based terminal missile defense role, that led the navy to continue modifying
existing block iv missiles for the bmd
mission.
The SM-2 block eva thus became a key
albeit temporary part of the navy's
lower tier, terminal ballistic missile
defense system. Meanwhile the SM-3 had established
itself as a key us weapon for conducting
upper tier, exo-atmospheric engagements
of short medium and later
intermediate-range ballistic missiles. Entering service later in the decade in
conjunction with aegis 5 bermudian
dollars and 10 cents and as part of paa phase 2. The SM-3 block iia will provide
greater regional coverage against Intermediate-Range Ballistic Missiles (IRBM).
This version features a higher burnout
velocity a more advanced seeker better
able to discriminate between warheads
and decoys, engage on remote capability
and nearly double the range of earlier AM-3 interceptors. The SM-3 is not the final standard
missile variant. The SM-6 which currently
is in low rate initial production
combines an SM-2 block iv airframe in
the active seeker from the aim 120
advanced medium range air to air missile, amram and is the navy's next generation
extended range anti-air warfare
interceptor.
This will increase the ability of aegis
warships to engage air targets beyond
their radar horizon and reduces aegis
weapon systems reliance on radar
illuminators. A variant also may play a role in future
sea based terminal ballistic missile
defenses.
