| __TECH ISP - Solar Electric Propulsion Potential Mission Applications__ *(Site not responding. Last check: 2007-10-16)* |

| | The fundamental performance expectation of a space mission, regardless of propulsion type, is specified by the "Rocket Equation", which relates the ratio of final to initial masses to the ratio of the Delta V to the **specific** **impulse**, which is proportional to the propellant velocity. |

| | The trends shown on Figure 2 then imply that for a given mission there is a **specific** **impulse** that minimizes the total mass of the electric propulsion system (which is closely approximated by the sum of the power and propellant masses). |

| | It is important to note that the optimum **specific** **impulse** tends to increase both with increasing mission Delta V (as suggested by Figure 1) and with decreasing **specific** mass (the ratio of total mass to power level) of the spacecraft. |

| www.inspacepropulsion.com /tech/solar_elec_prop__missionapps.html (1070 words) |