Pocket Rocket
 Version 2.0
Copyright ©2021by Paul Niquette. All rights reserved.
NASA-GMP Satellite
NASA-GMP Satellite with Proposed Pocket Rocket Embedded at the Center-of-Mass

Wouldn't it be great to have an enclosed mechanical 'drive' that produces thrust and requires no interaction with material things on the outside? 
No torquing of wheels rolling on rails or pavement, no propellers churning through water or blowing holes in the atmosphere, no burning fluids passing through turbines, no exhaust gases expelled through nozzles. 
That would sure be great, all right.  And in space, there are no 'material things' to interact with!  Only one choice: rocketry and plenty of consumption and depletion, whether by chemistry or by ionized atoms accelerated through electrical grids.  Within the solar system, an 'ionic' propulsion system does benefit from a bountiful photovoltaic energy source, the sun!
So does any Inertial Propulsion (IP) system(If it can be made to work.)
For this entry, your puzzle-master has coined the expression Pocket Rocket to emphasize the isolation of the IP system from outside interactions.  The word 'pocket' also celebrates the mechanical benefits of zero windage losses assured by the vacuum in space.

Solvers are invited to regard the Pocket Rocket challenge as a sequel to Trampoline Deorbiting System puzzle.  Imagine equipping every orbital satellite with a Pocket Rocket.  At the end of the satellite's service life, when its thrusters have run out of fuel, the Pocket Rocket is turned on.  Operating in retrograte, the satellite simply nudges itself down into disposal orbits.  Hey, operating in prograde, the Pocket Rocket can use solar energy to enable the satellite to overcome atmospheric drag indefinitely without chemical thrusters!

There are hundreds of Inertial Propulsion inventions.  Just take a look at these IP searches by Google and by Bing.  Consider one inventor named Robert Cook who has spent his life developing versions of Cook Inertial Propulsion (CIP).  His work is documented in the 1980 e-book...

Death of Rocketry by Joel Dickenson with Robert Cook

...an immense literary effort, which also includes information about other IP inventors...

Cuff, Dean, Farrall, Foster, Goldschmidt, Kellogg, Laskowitz, Matyas, Novak, Nowlin


In those ten thumbnail drawings from patent applications, there are mechanical proposals for devices invented to produce Inertial Propulsion.  Seven clearly feature spinning counter-weights or eccentrically driven masses constrained to follow circular motion; three invention-disclosures show spring-loaded contraptions and trip-hammers.

Whether any of those patents were actually issued is not important to us here, because after 41 years they would all have expired.

 The filing of a patent application is a clerical task.  The USPTO will not refuse filings for IP inventions -- even for perpetual motion machines.  The application will be filed and then may or may not be rejected by the patent examiner, after he or she has done a formal examination.  If a patent is granted, it does not mean that the invention actually works.  It just means that the examiner believes that it works, or was unable to figure out why it will not work.  Hmm.

But every inventor knows that patent attorneys do not work for free.  Thus, we can assume that each of the 10 inventors put plenty of effort -- and money -- into their respective IP concepts. Along comes a most elegant invention named 'Niquette Inertial Propulsion'.  NIP was invented in 2021, and it does not appear in a patent application. Yet.


Fig. 0. Niquette Inertial Propulsion (NIP) Concept

Fig. 0 and the other schematic sketches in the Pocket Rocket puzzle use their black frames to represent rigid structures, each containing all their NIP elements inside -- the Pocket.

Let us begin our analysis of the NIP concept, which applies...

Nine Design Criteria
  1. Twin Masses on Telescopic Arms
  2. Common Eccentric Drive Axis E
  3. Counter-Rotating and Synchronized
  4. Coaxial and Coplanar Configuration
  5. Motion Constrained by Circular Track
  6. Solar Powered Electrically Driven Motor
  7. All Forms of Friction Matched by Drive Torques
  8. Radial Inertial Forces Matched by Rigid Frame
  9. No Expenditure of Mass in Operation
Theory of Operations

We start with how the NIP concept achieves Inertial Propulsion. 

Fig. 1 depicts one
mass M of the 'twin' masses inside the NIP unit as a sphere or cylinder (in red) rotating at constant angular velocity ω clockwise around a circle with radius R.  Motion is constrained by a rigid track (in blue).  For convenience, numbers mark the positions of twelve points around the circle.  The mass M passes each successive mark at equal time intervals (t = θ / ω).

NIP-Theory of Operation

Fig. 1. Simplified NIP showing one mass M rotating clockwise.

The mass M is connected to the drive axis by a telescopic arm (also in red).  The drive
axis itself is offset by
∆R from the center of the circular track. The outward pointing arrows (in black) represent the instantaneous centrifugal force imposed on the track by the rotating mass M.  That force varies with the tangential velocity v, which is determined by the instantaneous length of the telescopic arm r from the drive axis.

The changing tangential velocity
v of mass M exerts a variable centrifugal force on the track, which is strongest at the 12-o’clock position where r = R + R, and the centrifugal force is weakest at the 6-o’clock position where r = R - R.  That intentional imbalance converts circular motion into a pulsating linear force inside the NIP unit.  Meanwhile, a synchronized, counter-rotating mass (not shown in Fig. 1) produces matching centrifugal forces at those locations (12-and-6), thus making them additive in the 6-to-12 direction (vertically upward in Fig. 1)!  Happily, in the lateral positions (1-11, 2-10, 3-9, 4-8. 5-7) components of the centrifugal forces from the two masses (horizontal in Fig. 1) cancel each other out. 

Therefore, the
Pocket Rock with NIP provides a vectored force from inside the spacecraft.

Does the NIP concept work?



Centrifugal versus Centripetal

The expression centrifugal force is the subject of confusion -- even occasional controversy.  Solvers of the Circling: Ground and Sky will find a rather informal treatment of this subject -- only mentioning that the terminology defined elsewhere as a particular kind of fictitious force also known as a pseudo force. the fictional force fCENTRIFUGAL is directed away -- "fleeing" -- from the center of curvature and thus sharing a common root with the word "fugitive."

Hypernote: Patent drawings collected by Joel Dickensen and Robert Cook and published in Death of Rocketry (1980)...

  IP Inventions