大 Motivation Traditional propulsion uses propellant as a reaction mass Advantages ability to move center of mass of spacecraft (Momentum conserved when propellant is included) Independent (and complete) control of each spacecraft Disadvantages Propellant is a limited resource Momentum conservation requires that the necessary propellant mass increase exponentially with the velocity increment(AV) Propellant can be a contaminant to precision optics DIl EMFF Final review ug.29,2003DII EMFF Final Review Aug. 29, 2003 Motivation Motivation • Traditional propulsion uses propellant as a reaction mass • Advantages – Ability to move center of mass of spacecraft (Momentum conserved when propellant is included) – Independent (and complete) control of each spacecraft • Disadvantages – Propellant is a limited resource – Momentum conservation requires that the necessary propellant mass increase exponentially with the velocity increment (∆V) – Propellant can be a contaminant to precision optics