Advanced Technology in Propulsion - ELECTRON SPIRAL TOROID PROPULSION (EST)

ELECTRON SPIRAL TOROID PROPULSION (EST)

          A revolutionary method has been discovered to store large amounts of energy as magnetic field energy with virtually no mass, using the newly patented Electron Spiral Toroid (EST). The EST has large total energy and low mass, potentially resulting in the advances of the space propulsion. An EST is calculated to store 10 12 joules of magnetic field energy in a containment of 235 kg, replacing a Titan rocket's 700,000 kg of fuel with 32 kg of thruster gas.

    

   

 The EST is a hollow toroid of electrons, all spiraling in parallel paths in a thin outer surface. The EST is charge neutral, being surrounded by ions which provide the small electric field. This makes the EST force free. The parallel paths are current loops, which create a very large internal magnetic field. Microwave energy may be added to raise electrons to 10,000 ev. Propulsion would heat ions without combustion through collisions with the EST surface, ejecting them for thrust. The ions are contained by electric fields until ejected; thus protecting mechanical parts. The thrust can be shut off when required. Proof-of-concept tests have shown EST energy loss rates to be small.

WATER THE ULTIMATE PROPELLANT

Advanced Technology in Propulsion - PLASMA BALLON

PLASMA BALLON

         One intriguing prospect is a propellant less propulsion concept called as plasma sail. The concept was developed by Robert Winglee, a scientist at the University of Washington in Seattle. This Mini-Magnetosphere Plasma Propulsion, or M2P2 for short, takes advantage of the natural environment of space. M2P2 technology creates a huge magnetic bubble around an interplanetary craft. In deploying the mini-magnetosphere, this plasma "balloon" interacts with high-speed ionized particles shed by the Sun which, in turn, push the vehicle through space.  Plasma sail technologies are faster

than ion and chemical propulsion and therefore could cut conventional trip times to the outer planets in half.

AEROCAPTURE

         

           Aerocapture technology is a flight maneuver that inserts a spacecraft into orbit around a planet or moon by using the destination's atmosphere like a "brake." The dense atmosphere creates friction, which is used to slow down a craft, transferring the energy associated with the vehicle's high speed into heat. Therefore this approach requires significant thermal protection. There is no need for any on-board propulsion. The main advantage of aero capture is reduced mass and use of a smaller, less-expensive launcher. This technique gets a vehicle to a destination quickly, hastening start-up of science operations.

         Aerocapture is part of a unique family of "aero assist" technologies being developed by NASA for science missions to any planetary body with an appreciable atmosphere. These destinations could include Mars, Venus and Saturn's moon Titan, along with the outer planets.

ANTIGRAVITY PROPULSION

Advanced Technology in Propulsion - VASIMR MODE

VASIMR MODE

               The variable- specific-impulse magneto plasma rocket (VASIMR) is high powered, electro thermal plasma

rocket, capable of modulating the exhaust at constant power. An electrode less design enables the rocket to operate at power densities much greater than those of more conventional magneto plasma or ion engines. VASIMR is intended to bridge the gap between high-thrust, low-specific impulse propulsion systems and low-thrust, high-specific impulse systems. Therefore it is capable of functioning in either mode placing the VASIMR far ahead of anything available today. This rocket utilizes hydrogen as its propellant which can be operated at relatively low cost.

            The VASIMR is expected to be commercially useful for boosting communication satellites and other Earth-orbiting spacecraft to higher orbits, retrieving and servicing spacecraft in high orbits around the Earth, and boosting high-payload robotic spacecraft on very fast missions to other planets. The greatest potential of the VASIMR is expected to lie in its ability to significantly reduce the trip times for human missions to Mars and beyond. This reduction in times is expected to enable long-term exploration of outer space by humans — something that conventional rocket designs now preclude.

            The VASIMR contains three major magnetic cells — the forward, central, and after cells. A plasma is injected into these cells, then heated, then expanded in a magnetic nozzle.  During operation of the VASIMR, a neutral gas (typically, hydrogen) is injected into the forward cell, where it is ionized. The resulting plasma is then heated further in the central cell which serves as an amplifier, to the desired temperature and density, by use of radio-frequency excitation and ion cyclotron resonance. Once heated, the plasma is magnetically and gas-dynamically exhausted by the aft cell to provide modulated thrust.

Advanced Technology in Propulsion - Solar energy for propulsion (solar sail)

2) Solar energy for propulsion (solar sail)

            A solar sail is a spacecraft propelled by sunlight. Whereas a conventional rocket is propelled by the thrust produced by its internal engine burn, a solar sail is pushed forward simply by light from the Sun. This is possible because light is made up of packets of energy known as “photons,” that

act like atomic particles, but with more energy. When a beam of light is pointed at a bright mirror-like surface, its photons reflect right back, just like a ball bouncing off a wall. In the process the photons transmit their momentum to the surface twice – once by the initial impact, and again by reflecting back from it. Thus propelled by a steady stream of reflecting photons, the bright surface is pushed forward.

            There are three components to a solar sail-powered spacecraft:

• Continuous force exerted by sunlight
• A large, ultra thin mirror
• A separate launch vehicle

Advanced Technology in Propulsion - PHOTON PROPULSION

PHOTON PROPULSION

A form of rocket propulsion, still in the earliest stages of development, in which the reaction is produced by electromagnetic radiation. Types of photon propulsion are:

1) Antimatter (photon rocket)

             Antimatter is the opposite of normal matter, of which the majority of our universe is made. The presence of antimatter in our universe was considered to be only theoretical.

            These anti-particles are, literally, mirror images of normal matter. Each anti-particle has the same mass as its corresponding particle, but the electrical charges are reversed. Here are some antimatter discoveries of the 20th century:

• Positrons - Electrons with a positive instead of negative charge. Discovered by Carl Anderson in 1932, positrons were the first evidence that antimatter existed.
• Anti-protons - Protons that have a negative instead of the usual positive charge. In 1955, researchers at the Berkeley Bevatron produced an antiproton.
• Anti-atoms - Pairing together positrons and antiprotons, scientists at CERN, the European Organization for Nuclear Research, created the first anti-atom. Nine anti-hydrogen atoms were created, each lasting only 40 nanoseconds. As of 1998, CERN researchers were pushing the production of anti-hydrogen atoms to 2,000 per hour.

              When antimatter comes into contact with normal matter, these equal but opposite particles collide to produce an explosion emitting pure radiation, which travels out of the point of the explosion at the speed of light. Both particles that created the explosion are completely annihilated, leaving behind other subatomic particles. The explosion that occurs when antimatter and matter interact transfers the entire mass of both objects into energy. Scientists believe that this energy is more powerful than any that can be generated by other propulsion methods.

Advanced Technology in Propulsion - LASER PROPULSION

c) Traveling wave

 

    A third type of plasma accelerator, sometimes called the magnetic-induction plasma motor, offers potential advantages over both the foregoing accelerators. It requires neither magnets nor electrodes, and relies on currents being induced in the plasma by a traveling magnetic wave. If the current in a conductor surrounding a tube containing plasma increases, the magnetic field strength in the plane of the conductor will increase. Then an electromotive force will be induced in any loop in this plane. If the conductor current increases rapidly enough, the induced electric field will establish substantial plasma current. The induced magnetic field and plasma current then interact to cause a body force normal to both, which tends to compress the plasma toward the axis of the tube and expel it axially. A traveling-wave accelerator makes use of a number of sequentially energized external conductors along the tube. As the switches are fired in turn, the magnetic field lines move axially along the tube, interacting with induced currents and imparting axial motion to the plasma.

               The inward radial force on the plasma this accelerator appears to offer an advantage in keeping the high temperature plasma away from the solid walls of the tube. The fact that no electrodes are needed is also an attractive feature

LASER PROPULSION

             

            Laser propulsion is a form of beam-powered propulsion where the energy source is a remote (usually ground -based) laser system and separate from the reaction mass. This form of propulsion differs from a conventional chemical rocket where both energy and reaction mass come from the solid or liquid propellants carried on board the vehicle. Types of laser propulsion are:

1) Ablative Laser Propulsion

Advanced Technology in Propulsion - INTRODUCTION

INTRODUCTION

          Any technique used for transmitting a mass from one point to another in the aerospace environment is called as propulsion. From past till now, propulsion has been one of the most active fields of research for many scientists. The main reason for this is the need for speed, faster trip time, exploration and discovery.

          Some of the advanced technologies in rocket and spacecraft propulsion which are used and to be used in the near future are given below:

ELECTRIC PROPULSION

           Some fundamentally different concept was introduced for accelerating the propellant mass to overcomes the limitations of chemical thermodynamic expansion. Into this breech steps the family of electric propulsion possibilities.

          Historically, conceptually and pragmatically this field has tended to subdivide into three categories:

1)       Electro thermal propulsion

             In this process propellant is heated by some electrical process then expanded through a suitable nozzle. The arc jet is an electro thermal rocket because it uses electrical energy to heat a propellant. In this method, an annular arc is created in the chamber and the propellant is heated to high temperatures as it interacts with the arc. After the heating, the propellant is expanded through a conventional nozzle. This type of propulsion takes advantage of using hydrogen as a propellant, and, like nuclear rockets, experiences a similar performance gain in specific impulse (up to 1,200 seconds). Unlike nuclear rockets, arc jets are small, producing little more than several pounds of thrust.

2) Electro static propulsion