Navy Researchers Fire 1
Navy Researchers Fire
1,000th Shot on Laboratory Electromagnetic Railgun
By Grace Jean,
Office of Naval Research.
Arlington, Virginia -- October 31, 2011 -- (NNS)
-- Scientists at the Naval Research Laboratory (NRL) hit a materials research
milestone in the Office of Naval Research's (ONR) Electromagnetic Railgun
program when they fired a laboratory-scale system for the 1,000th time Oct. 31.
"A significant amount of development has been coming out of
NRL to support the program," said Roger Ellis, ONR's Electromagnetic Railgun (EMRG)
program officer. "It's a key piece of making railgun successful."
The EMRG is a long-range weapon that launches projectiles
using electricity instead of chemical propellants. Under development by the
Department of the Navy (DON) for use aboard ships, the system will provide
Sailors with multi-mission capability, allowing them to conduct precise naval
surface fire support, or land strikes; cruise missile and ballistic missile
defense; and surface warfare to deter enemy vessels.
"The weapon does all its damage because of its speed," said
Dr. Roger McGinnis, program executive for ONR's Naval Air Warfare and Weapons
Department, which oversees EMRG. Launched at 2 to 2.5 kilometers per second
(4,500 to 5,600 mph) without using explosives, the projectile reaches its target
at speeds that require only a small charge similar to that found in automobile
airbags to dispense its payload, eliminating the objective through the inherent
"EMRG will provide the Department of Defense with an
advantage in future conflicts by giving troops the ability to fire weapons
inexpensively against targets," McGinnis said.
As part of the EMRG development program, ONR and NRL co-funded
scientists at NRL to build and operate a 6-meter long, 50 mm diameter railgun as
a subscale experimental lab at the Materials Testing Facility (MTF). Researchers
fired the first shot in March 2007. After improving the gun's sliding armature
and rails, the lab has fired an average of 300 shots per year since 2008.
A railgun launches projectiles by generating magnetic fields
created by high electrical currents that accelerate a sliding metal conductor,
or armature, between two rails.
"The 1,000th shot is testing new ideas of how the armature
interacts with the rails," said Dr. Robert Meger, head of NRL's charged particle
physics branch, which conducts about 30 experiments annually on the railgun.
Following each test firing, researchers dismantle the gun to examine all the
components. They slice up the rails for further analysis under a microscope to
reveal surface damage.
During the course of firing all 1,000 shots, NRL scientists
have experimented with a variety of materials and geometries to determine which
ones can withstand the metal-melting temperatures and pressures of shooting a
1.5-megajoule energy weapon. One megajoule of energy is equivalent to a 1-ton
car traveling at 100 miles per hour.
"We've really explored a lot of territory," ONR's Ellis said.
"When you couple what we're seeing in testing with what we're seeing in modeling
and simulation, it results in some interesting barrel shapes that you wouldn't
intuitively think about. Railgun barrels don't necessarily have to be round as
in most conventional gun designs."
Since 2005, scientists have been working to increase the
railgun's barrel life, muzzle energy and size. Ultimately, their work will help
to produce a 64-megajoule railgun with a range of about 220 nautical miles.
"You really have to look at the course of our understanding
from the first day they shot to the 1,000th shot today, and how much our
understanding of the rail life has dramatically increased, and how much science
we have applied to ensure that we're on the path toward a future fieldable
system," Ellis said.
Materials science breakthroughs resulting from the test
firings have given researchers confidence to transition new technologies to a
scaled-up experimental launcher at Naval Surface Warfare Center Dahlgren,Va.,
which fired a world record setting 33-megajoule shot in December 2010.
ONR provides the science and technology necessary to maintain
the Navy and Marine Corps' technological advantage. Through its affiliates, ONR
is a leader in science and technology with engagement in 50 states, 70
countries, 1,035 institutions of higher learning and 914 industry partners. ONR
employs approximately 1,400 people, comprising uniformed, civilian and contract
personnel, with additional employees at the Naval Research Lab in Washington,
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