The navy is probably going all magnetic rail guns on their warships. In 2008, the Chief of Naval Operations Adm. Gary Roughead witnessed firsthand a successful and world-record test firing of an electromagnetic rail gun at Naval Surface Warfare Center, Dahlgren.
A rail gun uses electricity vice chemical propellants, which current shipboard guns use, to fire projectiles at a range exceedingly 200 miles and at a velocity of mach seven. In comparison, the fleet's standard shipboard MK45 five-inch gun has a range of about 20 miles.
http://www.navy.mil/search/display.asp?story_id=34727So our ships can sit over 100 miles away from shore or more and pound almost any enemy fortification or army no matter where they are. Now that's power projection.
Why is the Navy thinking about magnetic rail guns? What's wrong with the old tried and true?
The launcher (barrel) contains a pair of metal conducting rails embedded in a structure made of composite materials. Very strong opposing magnetic fields are generated within the launcher by a high current pulse that flows through the rails and a bridging armature positioned behind the projectile when the rail gun is fired. These fields create a propulsive force that accelerates the armature and projectile out of the barrel. The GPS-guided projectile will exit the launcher at approximately 2500 meters/second. On the way to its target, the projectile would leave the Earth’s atmosphere, making it less susceptible to jamming or interception, and minimizing interference with friendly aircraft upon re-entry into airspace.
When operational, the EMRG will provide high-volume, precise, and time-critical fires in all-weather conditions. The goal of the Office of Naval Research rail gun project is to develop and smoothly transition prototype system that can deliver fires with high accuracy and lethality at distances greater than 200 nautical miles. The rounds will contain little or no high explosive material. Instead, they will inflict damage bway of high-velocity impact. With no explosives or propellants, the logistics of supporting the weapon will be simplified and crew and shsafety will be enhanced.
Railguns provide a capability for sustained, offensive power projection, complementary to missiles and tactical aircraft. Railguns may be a cost-effective solution to the Marine Corps Naval Surface Warfare Support future assault requirements for expeditionary maneuver warfare because of their unique capability to simultaneously satisfy three key warfighting objectives: (1) extremely long ranges; (2) short time-of-flight; and (3) high lethality (energy-on-target).
One important distinction between railguns and propellant-based guns is the difference in muzzle velocity. The 5-inch/54and 5-inch/62guns of today achieve muzzle velocities of approximately 800 m/s. In contrast, a railgun can accelerate a projectile to hypersonic velocities of 2500 m/s or Mach 7 and greater, enabling more that 200 nautical mile ranges within a six-minute time of flight. Such high muzzle velocities preclude the need for post-launch rocket-assist to achieve extended ranges. In an indirect fire mode, the projectile flight profile is predominantly exo-atmospheric, reducing the deconfliction problem and potential for Global Positioning System jamming.
http://www.globalsecurity.org/military/systems/ship/systems/emrg.htmIt has now been shown that magnetic launch systems are possible, not just some wacky science fiction dream. The small units that can fit aboard a Navy ship can get a projectile to 2500 meters per second (m/s), escape velocity is 11,200 m/s so we're almost a quarter there with a small unit. The only thing required is to increase the size and power. The last link gave a power requirement of 30 mega watts for the 2500 m/s system. The required amount of power will be quite a bit more than that but we should be able to power it with solar, a fairly large sized wind farm, or a coal or nuclear power plant.
Here is more about the maglev launch system:
A new approach for greatly reducing the unit cost to launch payloads into space is described. The approach, termed Maglev launch, magnetically levitates and accelerates space craft to orbital type speeds in evacuated tunnels at ground level, using superconducting Maglev technology similar to that already operating for high speed passenger in Japan. Two Maglev launch systems are described. The near term Gen-1 Maglev launch system would accelerate heavy cargo craft (-40 tons) to 8 km/sec using electrical energy at a unit energy cost of only 50 cents per kilogram. No propellants would be required. After achieving orbital speed the Gen-1 cargo craft would exit into the atmosphere at a high altitude point (> 4000 meters) on the surface, and climb through the atmosphere to orbit. The aerodynamic deceleration and heating loads during the ascent through the atmosphere appear acceptable. A single Gen-1 facility could launch over 100,000 tons annually at a unit launch cost of less than $50 per kg of payload, compared to present costs of $10,000 per kg.
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4526501At $50 per kg you could launch yourself (or something equally heavy) for less than $5,000 instead of a couple of million. This is a breakthrough technology, there is no doubt.
Researchers in a group including Wenjiang Yang and his colleagues from the Beijing University of Aeronautics and Astronautics and the Chinese Academy of Sciences have investigated the possibility of the “Maglifter,” a maglev launch assist vehicle originally proposed in the 1980s. In this system, a spaceship would be magnetically levitated over a track and accelerated up an incline, lifting off when it reaches a velocity of 1,000 km/hr (620 miles/hr). The main cost-saving areas would come from reduced fuel consumption and the reduced mass of the spaceship.
“Magnetic levitation is a promising technology for future space transportation,” Yang told PhysOrg.com. “The most expensive part of space missions to low-Earth orbit is the first few seconds—getting off the ground.”
In their model of a test vehicle on a seven-meter-long track, Yang’s group used a suspension system based on bulk high temperature superconductors, which achieve highly stable levitation due to their diamagnetic and flux pinning properties. The researchers used an arrangement of YBCO bulk superconductors, which achieve their remarkable property of zero resistance at 77 K. When the superconductors were cooled to this temperature, the test vehicle levitated freely over the track.
http://www.physorg.com/news91272157.htmlThe Gen-1 reference design launches a 40 ton, 2 meter diameter spacecraft with 35 tons of payload. At 12 launches per day, a single Gen-1 facility could launch 150,000 tons annually. Using present costs for tunneling, superconductors, cryogenic equipment, materials, etc., the projected construction cost for the Gen-1 facility is 20 billion dollars. Amortization cost, plus Spacecraft and O&M costs, total $43 per kg of payload. For polar orbit launches, sites exist in Alaska, Russia, and China. For equatorial orbit launches, sites exist in the Andes and Africa. With funding, the Gen-1 system could operate by 2020 AD.
http://adsabs.harvard.edu/abs/2010AIPC.1208..121P
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