Search results
Results From The WOW.Com Content Network
Delta-v in feet per second, and fuel requirements for a typical Apollo Lunar Landing mission. In astrodynamics and aerospace, a delta-v budget is an estimate of the total change in velocity (delta-v) required for a space mission. It is calculated as the sum of the delta-v required to perform each propulsive maneuver needed during
Delta-v is typically provided by the thrust of a rocket engine, but can be created by other engines. The time-rate of change of delta-v is the magnitude of the acceleration caused by the engines, i.e., the thrust per total vehicle mass. The actual acceleration vector would be found by adding thrust per mass on to the gravity vector and the ...
Propellant depots in LEO are of little use for transfer between two low earth orbits when the depot is in a different orbital plane than the target orbit. The delta-v to make the necessary plane change is typically extremely high. On the other hand, depots are typically proposed for exploration missions, where the change over time of the depot ...
In aerospace engineering, mass ratio is a measure of the efficiency of a rocket.It describes how much more massive the vehicle is with propellant than without; that is, the ratio of the rocket's wet mass (vehicle plus contents plus propellant) to its dry mass (vehicle plus contents).
Hybrid-propellant rockets use a combination of solid and liquid propellant, typically involving a liquid oxidizer being pumped through a hollow cylinder of solid fuel. All current spacecraft use conventional chemical rockets (solid-fuel or liquid bipropellant) for launch, though some [note 3] have used air-breathing engines on their first stage ...
Dense propellant launch vehicles have a higher takeoff mass due to lower I sp, but can more easily develop high takeoff thrusts due to the reduced volume of engine components. This means that vehicles with dense-fueled booster stages reach orbit earlier, minimizing losses due to gravity drag and reducing the effective delta-v requirement.
The propellant mass fraction is the ratio of just the propellant to the entire mass of the vehicle at takeoff (propellant plus dry mass). 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.
The longer it can accelerate its own mass, the more delta-V it delivers to the whole system. In other words, given a particular engine and a mass of a particular propellant, specific impulse measures for how long a time that engine can exert a continuous force (thrust) until fully burning that mass of propellant.