09-30-2004, 10:05 PM
In a discussion over a couple of beers this evening, PhotoDan and I were looking for a new name to replace "Rockets Anonymous". We need some help from you fellow Rockets. If your suggestion for a new name is selected, I'll send you one of my world famous Toledo Team Scent air fresheners for your ride (see picture below). What a deal!!!
Here's some info on Rocketry to get your creative juices flowing (maybe we can all be Rocket Scientists).
A rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of a fast moving exhaust from within a rocket engine. The exhaust is formed from propellant which is carried within the rocket prior to its release. The thrust is due to Newton's 3rd Law of Motion. Often the term rocket is also used to mean a rocket engine.
In military terminology, a rocket generally uses solid propellant and is unguided. These rockets can be fired by ground-attack aircraft at fixed targets such as buildings, or can be launched by ground forces at other ground targets. During the Vietnam era, there were also air launched unguided rockets that carried a nuclear payload designed to attack aircraft formations in flight.
In military terminology, a missile, by contrast, can use either solid or liquid propellant, and has a guidance system.
Rockets range in size from tiny models that can be purchased at a hobby store, to the enormous Saturn V used for the Apollo program.
There are many different types of rockets, and a comprehensive list can be found in spacecraft propulsion.
Rockets have also been used for landing on the Moon, in the descent stage of the Apollo Lunar Module.
Most current rockets are chemical rockets. A chemical rocket engine may use solid propellant, such as the Space Shuttle's SRBs, or liquid propellant, like the Space Shuttle's main engines, or a hybrid. A chemical reaction is initiated between the fuel and the oxidizer in the combustion chamber, and the resultant hot gases accelerate out of a nozzle (or nozzles) at the rearward facing end of the rocket. The acceleration of these gasses through the engine exerts force ('thrust') on the combustion chamber and nozzle, propelling the vehicle (in accordance with Newton's Third Law). See rocket engine for details.
Rockets must be used when there is no other substance (land, water, or air) that a vehicle may push against, such as in space. In these circumstances, it is necessary to carry all the propellant within the vehicle.
Rockets are particularly useful when very high speeds are required, such as orbital speed (mach 25 or so). The speeds that a rocket vehicle can reach can be calculated by the rocket equation; which gives the speed difference ('delta-v') in terms of the exhaust speed and ratio of inital weight to final weight ('mass ratio').
Common mass ratios for vehicles are 20/1 for dense propellants such as liquid oxygen and Kerosene, 25/1 for dense monopropellants such as Hydrogen Peroxide, and 10/1 for liquid oxygen and liquid hydrogen. However, mass ratio is highly dependant on many factors such as the type of engine the vehicle uses and structural safety margins.
Sometimes, particularly in launch scenarios, the required velocity (delta-v) for a mission is unattainable because the propellant, structure, guidance and engines weigh so much as prevent the mass ratio from being high enough. This problem is frequently solved by staging - the rocket sheds excess weight (usually tankage and engines) to attain a higher effective mass ratio thus permitting a higher Delta-V.
![[Image: airfreshener.jpg]](http://img13.exs.cx/img13/4520/airfreshener.jpg)
Here's some info on Rocketry to get your creative juices flowing (maybe we can all be Rocket Scientists).
A rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of a fast moving exhaust from within a rocket engine. The exhaust is formed from propellant which is carried within the rocket prior to its release. The thrust is due to Newton's 3rd Law of Motion. Often the term rocket is also used to mean a rocket engine.
In military terminology, a rocket generally uses solid propellant and is unguided. These rockets can be fired by ground-attack aircraft at fixed targets such as buildings, or can be launched by ground forces at other ground targets. During the Vietnam era, there were also air launched unguided rockets that carried a nuclear payload designed to attack aircraft formations in flight.
In military terminology, a missile, by contrast, can use either solid or liquid propellant, and has a guidance system.
Rockets range in size from tiny models that can be purchased at a hobby store, to the enormous Saturn V used for the Apollo program.
There are many different types of rockets, and a comprehensive list can be found in spacecraft propulsion.
Rockets have also been used for landing on the Moon, in the descent stage of the Apollo Lunar Module.
Most current rockets are chemical rockets. A chemical rocket engine may use solid propellant, such as the Space Shuttle's SRBs, or liquid propellant, like the Space Shuttle's main engines, or a hybrid. A chemical reaction is initiated between the fuel and the oxidizer in the combustion chamber, and the resultant hot gases accelerate out of a nozzle (or nozzles) at the rearward facing end of the rocket. The acceleration of these gasses through the engine exerts force ('thrust') on the combustion chamber and nozzle, propelling the vehicle (in accordance with Newton's Third Law). See rocket engine for details.
Rockets must be used when there is no other substance (land, water, or air) that a vehicle may push against, such as in space. In these circumstances, it is necessary to carry all the propellant within the vehicle.
Rockets are particularly useful when very high speeds are required, such as orbital speed (mach 25 or so). The speeds that a rocket vehicle can reach can be calculated by the rocket equation; which gives the speed difference ('delta-v') in terms of the exhaust speed and ratio of inital weight to final weight ('mass ratio').
Common mass ratios for vehicles are 20/1 for dense propellants such as liquid oxygen and Kerosene, 25/1 for dense monopropellants such as Hydrogen Peroxide, and 10/1 for liquid oxygen and liquid hydrogen. However, mass ratio is highly dependant on many factors such as the type of engine the vehicle uses and structural safety margins.
Sometimes, particularly in launch scenarios, the required velocity (delta-v) for a mission is unattainable because the propellant, structure, guidance and engines weigh so much as prevent the mass ratio from being high enough. This problem is frequently solved by staging - the rocket sheds excess weight (usually tankage and engines) to attain a higher effective mass ratio thus permitting a higher Delta-V.