Rockets

Why Does a Rocket Work?

In space, an engine has nothing to push against. So how do rockets move there?English scientist Sir Isaac Newton listed three Laws of Motion. He did this more than 300 years ago. Rockets work by a scientific rule he discovered known as Newton's third law of motion (Read it first then only read further). The rocket pushes on its exhaust. The exhaust pushes the rocket, too. The rocket pushes the exhaust backward. The exhaust makes the rocket move forward.

Source: NASA

What is a rocket?

The word "rocket" can mean different things. Most people think of a tall, thin, round vehicle. They think of a rocket that launches into space. "Rocket" can mean a type of engine. The word also can mean a vehicle that uses that engine.

In space, rockets zoom around with no air to push against. What's going on?

Rockets and engines in space behave according to Isaac Newton's third law of motion: Every action produces an equal and opposite reaction.

When a rocket shoots fuel out one end, this propels the rocket forward — no air is required.

NASA says this principle is easy to observe on Earth. If you stand on a skateboard and throw a bowling ball forward, that force will push you and the skateboard back. However, because your weight on the skateboard is heavier than that of the bowling ball, you won't move as far.

That's the challenge engineers face when designing space engines. Yes, a small amount of thrust does push the spacecraft forward, but it often takes a great deal of fuel to get going anywhere quickly. More fuel means more weight, which adds to the cost of a mission.

To save on money when shooting for far-away planets such as Jupiter, some spacecraft whip around a planet (say, Venus) and use its gravity to get a speed boost. This shortens the time it takes to get to other destinations. This is sometimes known as a "gravity slingshot".

Rocket Anatomy with Functions

These are basic components involved in rockets. Knowing them means you understand rocket launches (and failures as well) more than just an average SpaceX or NASA fan.

Structure: Provides support structure for all the components,protects the inner workings of the vehicle, contains fairings and interfaces for sub- systems and stages, and houses moving components.

Propulsion: Contains the fuel, oxidizer, flowsystems, combustion chamber, nozzles, and other components needed to propel the rocket.

Power: This subsystem contains power storage,conditions that power for use, and distributes it accordingly.

Guidance, Navigation, and Control(GN&C): Contains attitude control system (ACS), reaction control systems (RCS), which might include thrust vector controls (TVC) and control surfaces(such as fins or wings), navigational sensors, such as inertial navigation units (INUs) and star trackers.

Payload: This is the reason for the rocket and contains the science instruments, cargo, or crew. The essential component of all important space launch vehicles.

Command and Data Handling (C&DH): Command computers,data processors, data storage systems, and the data distribution protocols and infrastructure.

Communication: Radios, low and high gain antennas, and telemetry systems.

Reentry Systems: These are for rockets that must safely return a payload to Earth and contain special braking systems, such as the orbital maneuvering system (OMS) thrusters (Space Shuttle), and reentry thermal protection, such as the shuttle tiles or the ceramic shields (Apollo capsules).

Emergency Systems: These systems are for use in fault condition situations and include sensors for leak, fire, and damage detection, backup systems, and abort systems.

Landing Systems: Vehicles that return have some means of landing the payload safely on Earth, which could include parachutes, wings, airbags, or even rockets.

You just became an Amateur Rocket Anatomist!