CAV 100 Rockets, Satellites & Spacecraft

Principles of Rocket Propulsion  Newton’s three laws of physical motion  1. A body remains at rest or in a state of motion in a straight line unless acted upon by an external force.  2. A force acting upon a body causes it to accelerate in the direction of the force. The acceleration is directly proportional to the force and inversely proportional to the mass of the object being accelerated.  3. For every action there is an equal and opposite reaction.

Energy Conversion  Potential energy-stored energy  Chemical form-gasoline  Nuclear form-plutonium  Kinetic energy-energy of motion

Classification of Rocket Engines  Chemically fueled liquid  Regenerative cooling  Bi-propellant  Mono-propellant  Hypergolic fuels

Chemically Fueled Solid  Grain or charge refers to how fuel is packed into the rocket case.  Fuel composed of fuel and oxidizer.

Nuclear and Electric Engines  Nuclear engine uses heat from fission.  Heats a working fluid to high temperature and expels it at high velocity.  Electric engines used for satellite station keeping.  Has low thrust rating-a few pounds-can operate a long time.

Guidance Systems  Preset-cruise missile  Command-wire guided  Homing-radar or infrared  Inertial-platform and gyros  Celestial-position of stars

Orbital Mechanics  An orbit is the path of a body or spacecraft under the influence of gravity or some other force.  Types of orbits-. Circle-most difficult to obtain. Circle-most difficult to obtain  Ellipse-most common  Parabolic-has energy to leave Earth orbit  Hyperbolic-leave Earth –transfer to gravity of moon

Newton’s Universal Law of Gravity  All bodies attract each other  Strength of attraction depends on-  The distance between objects  The mass of the objects

How A Satellite May Be Orbited  Orbital velocity-17,500MPH  Escape velocity-25,000MPH  Perigee-closest point  Apogee-most distant point  Satellite stays up because of a balance of forces-gravity and centrifugal force.  Satellites appear to stand still in a geosynchronous orbit 22,000 miles above equator

Satellite Technology  Meteorological  Communications  Navigation  Earth Resources  Scientific  Military

What coming?  Space station  Space shuttle  Duplication of systems  Space rescue  Ablation-removes heat by melting heat shield of spacecraft.  1000 passenger jets