New Propulsion System updated 10/10/01

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New Propulsion System

       
United States Patent
Patent number:     5,305,974
Date of patent:    Apr. 26, 1994
Spaceship Propulsion by Momentum Transfer

Abstract


A propulsion system for spaceships wherein a first electromagnetic projectile launcher(EMPL) accelerates "smart" projectiles into space and on appropriate trajectories to rendezvous with a distant spaceship at some later time. The smart projectiles stabilize themselves in space using a system of on board thrusters operated by computers. Laser beams and radio transmissions are directed at the spaceship and are monitored by sensors aboard the spaceship. Computers on board the spaceship determine any necessary course corrections for the projectiles based upon the spaceship's sensor system. Appropriate commands are radioed to the projectiles which execute the commanded maneuvers to alter their trajectories. The spaceship carries a second EMPL and a nuclear-powered electricity generating facility to provide electricity to operate the EMPL. The spaceship, the second EMPL and the nuclear power facility are all rotated axially about the long axis of the EMPL to provide both gyroscopic stabilization and also artificial gravity for the crew of the spaceship. The second EMPL is used to catch the projectiles which transfers the momentum of the projectiles to the spaceship thereby accelerating it in the desired direction. Additional acceleration of the spaceship is achieved by again launching the captured projectiles in a direction opposite to the desired direction of motion of the spaceship. The spaceship can be decelerated in a similar manner. Mars can be reached in two months using this system.


        Fixed these links  02/23/01

          Read my whole patent on Delphion Intellectual Property Network

          Or, check on any patent with the Delphion patent number search


Why is my propulsion system better?

     Because the specific impulse of my propulsion system is at least 3300 seconds and can be increased up to 10,000 seconds.  Perhaps you don't know what specific impulse is. Well, specific impulse is defined to be the ratio of the thrust of the rocket to the weight flow rate of the propellant. When stated in this manner it is difficult to understand. A simpler way to express it is the number of seconds that one pound of propellant would burn while producing one pound of thrust. It is a measure of the energy in the propellant.

The following is a table of specific impulses of various different propulsion systems.

Specific Impulse Comparions
Propulsion system        Specific Impulse (sec)
LOX-LH2 (space shuttle system)   450 - 475
O-BeH (most energetic chemical propellant)   705
Augustine Engine   900 - 1000
Nuclear thermal rocket (fission)      
      solid core    500 - 1100
      liquid core 1300 - 1600
      gas core    3000 - 7000
(*) Nuclear electric rocket      800 - 30000
Momentum exchange (my system)     3000 - 10000
(*) Ion drive (such as NASA Deep Space 1) 3000 - 25000
(*) Nuclear fusion rocket   1,000,000= (.033c)
(*) Anti-matter rocket 28,775,000=(.94c)
(*) Photon drive (light beam)   30,000,000= (1.0c)

 

The problem with all systems marked by (*) is that their total thrust is very low. Take the Ion drive used by the Nasa Deep Space 1 project. Its total thrust is measured in ounces (see Popular Science, 7/98, p.44)   These systems are therefore useless for transporting people to distant planets or other destinations.

So far it is still not clear why higher specific impulse is good - or how good it is. Let me give you a practical example. Consider the famous rocket equation given below:

          M/m = exp( dv/g*Isp )
where:
   M = initial total mass
   m = final total mass (after the fuel is used up)
   M/m = mass ratio
             exp = "e" raised to the power of  ( dv/g*Isp )
   dv = total delta velocity
   g = acceleration of gravity
   Isp = specific impulse of the fuel or the propulsion system

My plan calls for an outward velocity of 20 km/sec and the same for the return trip. This amounts to a total delta velocity of 40 km/sec or 40,000 m/sec.

Let's calculate the mass ratio for a LOX-LH2 rocket:

We have:   M/m = exp(40000/9.8 * 450) = exp(9.07) = 8693

Now we do the same for a nuclear thermal rocket with an Isp of 950 secs.

We now have:   M/m = exp(40000/9.8 * 950) = exp(4.296) = 73

Finally, try my system with an Isp of 3300 secs.

Now we get:   M/m = exp(40000/9.8 * 3300) = exp(1.24) = 3.44

The results are summarized in the table below.

Comparison of Propulsion Systems for 3000 MT Spaceship

Propulsion system Isp Total Mass(MT)   Total Cost at $1M/MT
LOX-LH2 (shuttle)    450    26,079,000 $26,079,000,000,000
Nuclear Thermal   950 219,000 $219,000,000,000
Momentum exchange 3300 10,320   $10,320,000,000