// PROPULSION SYSTEMS AND ENGINE TECHNOLOGY TERM
Total Impulse
Total impulse is the measure of the total propulsive push a rocket engine provides over its entire operating time. It is calculated by multiplying the average thrust by the duration of the engine's burn.
TECHNICAL DEFINITION
Total impulse is a key performance metric in aerospace propulsion, representing the integral of thrust with respect to time for the entire duration of a rocket engine's firing. Measured in Newton-seconds (N-s) or pound-force-seconds (lbf-s), it quantifies the total change in momentum a propulsion system imparts to a vehicle and is a function of propellant mass and specific impulse.
BACKGROUND
Specific impulse is a physical quantity defined as the ratio of change in momentum (impulse) to the mass used, usually fuel. It typically uses units of metres per second or feet per second. It is equivalent to thrust per mass flow rate.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- thrust-time integral
- I_t
- total propulsive impulse
- burnout impulse
- impulse bit
- propulsion energy
USAGE NOTE
It is a primary figure of merit used to classify and compare the overall performance capability of different rocket motors, especially solid rocket motors.
DEVELOPERS
Organizations developing technology related to Total Impulse.
Designs and manufactures reusable rockets and spacecraft. The total impulse of its Merlin and Raptor engine systems is a critical performance metric for achieving orbit and landing its launch vehicle boosters.
A world-recognized aerospace and defense leader in propulsion. The company develops engines like the RS-25, where delivering a precise and immense total impulse is a fundamental requirement for heavy-lift vehicles like NASA's Space Launch System.
An aerospace manufacturer developing rockets for commercial and governmental use. Its powerful BE-4 engine is designed to generate a very high total impulse, enabling heavy-lift launch capabilities for vehicles like New Glenn and ULA's Vulcan Centaur.
A leading developer of solid rocket motors (SRMs), including the large boosters for NASA's SLS. The total impulse for an SRM is a fixed, non-throttleable quantity that is precisely engineered during design to meet mission performance goals.
A provider of launch services for the small satellite industry. The design of its Rutherford engine for the Electron rocket is centered on delivering the exact total impulse needed to place small payloads into precise orbits.
The European prime contractor for the Ariane family of launch vehicles. It develops liquid propulsion systems, such as the Vulcain 2.1 engine, that are optimized to provide the required total impulse for launching heavy satellites to geostationary orbit.
The research and development arm for the U.S. Air Force and Space Force. Its Rocket Propulsion Division explores next-generation technologies aimed at increasing key metrics like total impulse to enable new military and space capabilities.