Poll: Would you volunteer for a trip to Mars if you knew you could never come back?

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=34727

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.htm

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=4526501

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.html

The 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

Dr. Howard M. Resh, in his book HYDROPONIC FOOD PRODUCTION, cites vegetable yield increases that are dramatic; identical cucumber plants produced 7,000 pounds per acre in soil but 28,000 pounds per acre when grown hydroponically and tomato yields that ranged from 5 to 10 tons per acre in soil but 60 to 300 tons per hydroponic acre. The reported results are typical for practically any plant. Said another way, to produce the total number of tomatoes consumed annually in Canada (400 million pounds) requires 25,000 acres of soil. Hydroponically, it would require only 1,300 acres.

http://www.simplyhydro.com/f_a_q.htm

The dramatic increase in yields with hydroponics is best illustrated if we consider the actual production figures of soil grown and hydroponically grown produce. Field grown tomatoes average yields ranging between 40,000 to 60, 000 pounds per acre; on the other hand top growing hydroponics facilities in the US and Canada report average yields of more than 650,000 pounds of tomatoes per acre. Additionally, given the fact that only 10 years ago top hydroponics producers were producing around 400,000 pounds per acre, the increase in yields with improvements in growing practices has been truly phenomenal. Similar production figures can be quoted for other agricultural produce like cucumbers with 10,000 pounds per acre for field production and 200,000 per acre for hydroponic greenhouse yields. Hydroponics lettuce and pepper yields too average around four times the corresponding yields of agricultural production.

http://www.buzzle.com/articles/hydroponics-in-commercial-food-production.html