PAPER PRESENTATION

PROPULSION

SUBMITTED FOR EXPOUND

Held at

MOHAMMED SATHAK COLLEGE OF ENGINEERING

on 20/08/2006 & 21/08/2006

Submitted by

VIJAY ANAND J, II year, BE, Mechanical engineering,

KONGU ENGINEERING COLLEGE, PERUNDURAI.

Email ID: vijay_anand7888@yahoo.com

VINAYAK RAJ KUMAR M, II year, BE, Mechanical engineering,

KONGU ENGINEERING COLLEGE, PERUNDURAI.

Email ID:mvinayak1012@yahoo.co.in

ABSTRACT

The only means of space travel is through ROCKET ENGINES. This rocket

engine is propelled through space by many ways. Some of them are nuclear fusion, light

and antimatter propulsion. The new idea of propulsion is ELECTROMAGNETIC

PROPULSION.

This idea was first proposed by Dr.DAVID GOODWIN, PROGRAM

MANAGER, U.S.DEPARTMENT OF ENERGY. He said that any conductor when coiled

by a current carrying wire attains magnetic property. Then they vibrate in the axis. When

this vibration is restricted in one direction it can be used as the method for propulsion.

The construction consists of a solenoidal wire and a metal conductor (super

conducting material). When the power supply is given to the coil, the metal conductor

attains magnetic property. Then they vibrate in their axis.

In order to restrict the vibration in one direction a SOLIDSTATE SWITCH is

used. During the passage of current there created a pulse which tends the metal conductor

to move the magnet. This solid state switch is used to increase the pulse. This pulse

created moves the magnet in one direction.

The main advantage is that the power required can be drawn from the thermal

energy given from the nuclear power station. This restricts difficulties in other type of

propulsions. The main disadvantage is that this just an idea and the metal vibrate in he

same place and they don’t move anywhere. Thus research over thi type of propulsion is

going on to restrict the vibration in one direction.

Spacecraft propulsion

A remote camera captures a close-up view of a Space Shuttle Main Engine during a test

firing at the John C. Stennis Space Center in Hancock County, Mississippi

Spacecraft propulsion is used to change the velocity of spacecraft and artificial

satellites, or in short, to provide delta-v. There are many different methods. Each method

has drawbacks and advantages, and spacecraft propulsion is an active area of research.

Most spacecraft today are propelled by heating the reaction mass and allowing it to flow

out the back of the vehicle. This sort of engine is called a rocket engine.

All current spacecraft use chemical rocket (bipropellant or solid-fuel) for launch, though

some (such as the Pegasus rocket and SpaceShipOne) have used air-breathing engines on

their first stage. Most satellites have simple reliable chemical rockets (often

monopropellant rockets) or resistojet rockets to keep their station, although some use

momentum wheels for attitude control. Newer geo-orbiting spacecraft are starting to use

electric propulsion for north-south stationkeeping. Interplanetary vehicles mostly use

chemical rockets as well, although a few have experimentally used ion thrusters with

some success (a form of electric propulsion).

ELECTROMAGNETIC PROPULSION

For decades, the only means of space travel have been rocket engines that run off

of chemical propulsion. Now, at the beginning of the 21st century, aerospace engineers

are devising innovative ways to take us to the stars, including light propulsion, nuclear-

fusion propulsion and antimatter propulsion. A new type of spacecraft that lacks any

propellant is also being proposed. This type of spacecraft, which would be jolted through

space by electromagnets, could take us farther than any of these other methods.

An Electromagnet

An electromagnet starts with a battery (or some other source of power) and a

wire. What a battery produces is electrons.

If you look at a battery, say at a normal D-cell from a flashlight, you can see that

there are two ends, one marked plus (+) and the other marked minus (-). Electrons collect

at the negative end of the battery, and, if you let them, they will gladly flow to the

positive end. The way you "let them" flow is with a wire. If you attach a wire directly

between the positive and negative terminals of a D-cell, three things will happen:

1. Electrons will flow from the negative side of the battery to the positive side as

fast as they can.

2. The battery will drain fairly quickly (in a matter of several minutes). For that

reason, it is generally not a good idea to connect the two terminals of a battery to

one another directly. Normally, you connect some kind of load in the middle of

the wire so the electrons can do useful work. The load might be a motor, a light

bulb, a radio or whatever.

3. A small magnetic field is generated in the wire. It is this small magnetic field

that is the basis of an electromagnet.

4. For example, if you wrap your wire around a nail 10 times, connect the wire to the

battery and bring one end of the nail near the compass, you will find that it has a

much larger effect on the compass. In fact, the nail behaves just like a bar magnet.

A simple electromagnet

However, the magnet exists only when the current is flowing from the battery. What you

have created is an electromagnet! You will find that this magnet is able to pick up small

steel things like paper clips, staples and thumb tacks.

When cooled to extremely low temperatures, electromagnets demonstrate an unusual

behavior: For the first few nanoseconds after electricity is applied to them, they vibrate.

David Goodwin, a program manager at the U.S. Department of Energy's Office of High

Energy and Nuclear Physics, proposes that if this vibration can be contained in one

direction, it could provide enough of a jolt to send spacecraft farther and faster into space

than any other propulsion method in development.

Jolting Into Space

The U.S. Department of Energy (DOE) is typically not in the business of developing

propulsion systems for NASA, but it is continually working on better superconducting

magnets and very rapid, high-power solid-state switches. In the mid-1990s, Goodwin

chaired a session for NASA's Breakthrough Propulsion Physics Project, which is working

to design propulsion systems that have no propellant, use a very high energy system and

can eventually overcome inertia. "It seemed that there should be some way to use this

technology that [DOE scientists] were developing to help NASA meet their goals, and it

basically sprang from that," Goodwin said. What sprang from the DOE research

Goodwin's idea for a space propulsion system that uses super-cooled, superconducting

magnets vibrating 400,000 times per second. If this rapid pulse can be directed in one

direction, it could create a very efficient space propulsion system with the ability to

achieve speeds on the order of a fraction of 1 percent of the speed of light.

CONSTRUCTION

WORKING

The heart of the system is the super-cooled, solenoid-style

electromagnet and the metal plate that causes an asymmetry

in the magnetic field.

During the first 100 nanoseconds (billionths of a second) of an electromagnet ramping

up, the electromagnet is in a non-steady state that allows it to pulse very rapidly. After it

ramps up, the magnetic field reaches a steady state and no pulsing occurs. Goodwin

describes the electromagnet he is using as a solenoid, which is basically a

superconducting magnetic wire wrapped around a metal cylinder. The entire structure

will have a diameter of 1 foot (30.5 cm), a height of 3 feet (91.4 cm) and a weight of

55.12 pounds (25 kg). The wire used for this propulsion system is a niobium-tin alloy.

Several of these wire strands will be wrapped into a cable. This electromagnet is then

super-cooled with liquid helium to 4 degrees Kelvin (-452.47 F / -269.15 C).

For the magnet to vibrate, you need to cause an asymmetry in the magnetic field.

Goodwin plans to deliberately introduce a metal plate into the magnetic field to enhance

the vibrating movement. This plate would be made of either copper, aluminum or iron.

The aluminum and copper plates are better conductors and have a greater effect on the

magnetic field. The plate would be charged up and isolated from the system to create the

asymmetry. Then the plate would be drained of electricity in the few microseconds

(millionths of a second) before the magnet were allowed to oscillate in the opposite

direction.

"Now, the catch here is, can we use this non-steady state condition in such a way that it

only moves in one direction?" Goodwin said. "And that's where it's very uncertain that

that can be done. That's why we would like to do an experiment to find out." Together

with the cooperation of Boeing, Goodwin is seeking funding from NASA to perform such

an experiment.

The key to the system is the solid-state switch that would mediate the electricity being

sent from the power supply to the electromagnet. This switch basically turns the

electromagnet on and off 400,000 times per second. A solid-state switch looks something

like an oversized computer chip -- imagine a microprocessor about the size of a hockey

puck. Its job is to take the steady-state power and convert it to a very rapid, high-power

pulse 400,000 times per second at 30 amps and 9,000 volts.

Beyond Our Solar System

The U.S. Department of Energy also is working on plans for a nuclear space reactor for

NASA. Goodwin believes that this reactor could be used to power the electromagnetic-

propulsion system. The DOE is working to secure funding from NASA, and a 300-

kilowatt reactor could be ready by 2006. The propulsion system would be configured to

convert the thermal power generated by the reactor into electric power.

"For deep space, Mars and beyond, you pretty much need to go nuclear if you are

going to move any mass," Goodwin said. The reactor will generate power through the

process of induced nuclear fission, which generates energy by splitting atoms (such as

uranium-235 atoms). When a single atom splits, it releases large amounts of heat and

gamma radiation. One pound (0.45 kg) of highly enriched uranium, like that used to

power a nuclear submarine or nuclear aircraft carrier, is equal to about 1 million gallons

(3.8 million liters) of gasoline. One pound of uranium is only about the size of a baseball,

so it could power a spacecraft for long periods of time without taking up much room on

it. This kind of nuclear-powered, electromagnetically propelled spacecraft would be able

to traverse incredibly large distances.

HELIOPAUSE

The heliopause is the point at which the solar wind from the sun meets the interstellar

solar wind created by the other stars. It is located about 200 astronomical units (AU)

from the sun (the exact location of the heliopause is unknown). One AU is equal to the

average distance from the sun to the Earth, or about 93 million miles (150 million km).

For comparison, Pluto is 39.53 AU from the sun.

In order to move people, a much larger device would have to be built, but the 1-

foot diameter, 3-foot-tall electromagnetic could push small, unmanned spacecraft like an

interstellar probe to very far distances. The system is very efficient, according to

Goodwin, and it puts a lot of power through a superconductor. The rapid vibration would

likely bring the magnet to the edge of its strength. Thus the magnet can be vibrated, but it

will not go anywhere. And researchs said that there is one out of ten chance that it will

work. In future if it works it will be a major advantageous invention.