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A space vehicle's flight is determined by application of Newton's second law of motion: =, where F is the vector sum of all forces exerted on the vehicle, m is its current mass, and a is the acceleration vector, the instantaneous rate of change of velocity (v), which in turn is the instantaneous rate of change of displacement.
Most spacecraft have some variety of rocket engine, and thus most research efforts focus on some variety of rocket propulsion, such as chemical, nuclear or electric. Spacecraft design – a specialized form of systems engineering that centers on combining all the necessary subsystems for a particular launch vehicle or satellite .
A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It is often needed so that the spacecraft high-gain antenna may be accurately pointed to Earth for communications, so that onboard experiments may accomplish precise pointing for accurate collection and subsequent interpretation of data, so that the heating and cooling effects of sunlight and shadow ...
For rocket-like propulsion systems, this is a function of mass fraction and exhaust velocity; mass fraction for rocket-like systems is usually limited by propulsion system weight and tankage weight. [ citation needed ] For a system to achieve this limit, the payload may need to be a negligible percentage of the vehicle, and so the practical ...
RS-68 being tested at NASA's Stennis Space Center Viking 5C rocket engine used on Ariane 1 through Ariane 4. A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed jet of high-temperature gas produced by the combustion of rocket propellants stored inside the rocket.
In spaceflight, an orbital maneuver (otherwise known as a burn) is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth, an orbital maneuver is called a deep-space maneuver (DSM). [1] When a spacecraft is not conducting a maneuver, especially in a transfer orbit, it is said to be coasting.
In the cases of a single-stage-to-orbit (SSTO) vehicle or suborbital vehicle, the mass fraction equals the propellant mass fraction, which is simply the fuel mass divided by the mass of the full spaceship. A rocket employing staging, which are the only designs to have reached orbit, has a mass fraction higher than the propellant mass fraction ...
Gas-generator rocket cycle. Some of the fuel and oxidizer is burned separately to power the pumps and then discarded. Most gas-generator engines use the fuel for nozzle cooling. The gas-generator cycle, also called open cycle, is one of the most commonly used power cycles in bipropellant liquid rocket engines.