Pendulum rocket fallacy

About: Pendulum rocket fallacy is a research topic. Over the lifetime, 35 publications have been published within this topic receiving 177 citations.

The Physics of Rockets

Abstract: Although the Chinese are credited with the use of gunpowder rockets as early as several centuries B.C., and Hero of Alexandria invented a steam jet propulsion device about 100 B.C., most of the serious effort to develop rockets has occurred in the last three decades. Goddard in America made a complete study of rocket performance in 1914. The German all-out rocket program commenced in 1935 culminating in the V-2, which was first fired in September of 1944. Since 1938, intensive rocket research has been carried out by a number of American agencies, including a basic theoretical contribution by Malina in 1940. The present paper will concern itself only with that type of jet propulsion device designated as a "pure" rocket, i.e., a thrust producer which does not make use of the surrounding atmosphere. This restriction excludes propulsive duct devices such as the "turbojet" engine used in jet propelled airplanes of the P-80 type. No attempt will be made to discuss the aerodynamics of bodies moving at supersonic speeds, the electronic problems of rocket missile guidance and control, the measurement of physical quantities in the upper atmosphere, or the properties of weapon rockets. Even omitting these interesting fields, the science of rocketry embraces many phases of physics and chemistry, as will appear in later sections.

A Solution of the Goddard Problem

Abstract: The problem of optimizing the thrust of a vertically ascending rocket is solved here under the assumption of isothermal atmosphere in two important cases: 1) the jet Mach number and the fuel supply are sufficiently large; 2) the drag is a convex function of the velocityThe first case embraces all physical drags and is valid for the Earth; the second extends to all atmospheres, but is restricted to drags that arc fairly commonWith impulsive boosts in velocity admitted, the solution is shown to contain a finite number of such boosts in the sonic region of the rocket velocity, and to contain no coasting arcs except in the terminal stageAn absolute minimum is proved with the aid of a sufficient condition applicable to problems of optimum control

A more thorough analysis of water rockets: Moist adiabats, transient flows, and inertial forces in a soda bottle

Abstract: The water rocket 1 is a popular toy that is often used in first year physics courses to illustrate Newton’s laws of motion and rocket propulsion. In its simplest version, a water rocket is made of a soda bottle, a bicycle pump, a rubber stopper, and some piping see Fig. 1. The bottle is half-filled with water, turned upside-down, and air is pushed inside the bottle via a flexible pipe that runs through the stopper. When the pressure builds up, the stopper eventually pops out of the neck. The water is then ejected and the rocket takes off. Witnesses of the launch of a water rocket cannot but be amazed that such a simple device can reach a height of tens of meters in a fraction of a second. The popularity of water rockets extends beyond physics classrooms, with many existing associations and competitions organized worldwide. 1 The more than 5000 videos posted on YouTube with the words “water rocket” in their title testify to their popularity. Some of these videos involve elaborate technical developments such as multistage water rockets, nozzles that adapt to the pressure, the replacement of water by foam or flour, underwater rocket launches, and even a water-propelled human flight. The public’s passionate explorations with water rockets contrast with the small number of articles devoted to their analysis. I found only two papers 2,3 that treat the simplest possible rocket, similar to

Introduction to Rocket Science and Engineering

Abstract: What Are Rockets? The History of Rockets Rockets of the Modern Era Rocket Anatomy and Nomenclature Why Are Rockets Needed? Missions and Payloads Trajectories Orbits Orbit Changes and Maneuvers Ballistic Missile Trajectories How Do Rockets Work? Thrust Specific Impulse Weight Flow Rate Tsiolkovsky's Rocket Equation Staging Rocket Dynamics, Guidance, and Control How Do Rocket Engines Work? The Basic Rocket Engine Thermodynamic Expansion and the Rocket Nozzle Exit Velocity Rocket Engine Area Ratio and Lengths Rocket Engine Design Example Are All Rockets the Same? Solid Rocket Engines Liquid Propellant Rocket Engines Hybrid Rocket Engines Electric Rocket Engines Nuclear Rocket Engines Solar Rocket Engines Photon-Based Engines How Do We Test Rockets? The Systems Engineering Process and Rocket Development Measuring Thrust Pressure Vessel Tests Shake 'n Bake Tests Drop and Landing Tests Environment Tests Destructive Tests Modeling and Simulation Roll-Out Test Flight Tests Are We Thinking Like Rocket Scientists and Engineers? Weather Cocking Fuel Sloshing Propellant Vorticity Tornadoes and Overpasses Flying Foam Debris Monocoque The Space Mission Analysis and Design Process Back to the Moon Suggested Reading for Rocket Scientists and Engineers Index A Chapter Summary and Exercises appear at the end of each chapter.

Beating the Rocket Equation: Air Launch With Advanced Chemical Propulsion

Abstract: Performance figures are presented for reusable, winged rocket stages launched from several large transport aircraft, including the Boeing 747, the Russian Anotonov An-226, a large supersonic aircraft comparable to the XB-70 aircraft, which achieved Mach 3.1 flight with conventional turbojet propulsion in 1964, and a Mach 6 conceptual aircraft based on the MA145-XAB ramjet demonstrated in 1968. Advantages of air launch include a reduced ascent-to-orbit delta-velocity, reduced drag, the capability to launch at any latitude, and simplified abort modes. Launch from the XB-70 flight condition would allow a 22% reduction in delta-velocity required of the rocket and a significant reduction in drag incurred by rocket flight beginning at an atmospheric density 1/20th that of sea level. Launch from a Mach 6, 85,000-ft altitude condition would allow a 33% reduction in delta-velocity; ar eusable rocket of 262,000 lb launched at this condition could deliver a 23,500-lb payload to orbit utilizing a 523-s vacuum specific impulse advanced rocket engine. Fluorine/lithium‐hydrogen engines achieved 523 s in U.S. Air Force and NASA development programs of the 1960s and 1970s. Comparisons to ground-launched, all-rocket vehicles delivering equivalent payloads to orbit are presented. Fluorine propellant reactivity and engine development history are also discussed.