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Low-Thrust (LT) Trajectory Tool Development Activity What Is Low Thrust? Larry Kos MSFC Advanced Concepts Dept / TD30 Systems Analysis Team / TD33 6/9/2004. What Is Low Thrust?.
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Low-Thrust (LT) Trajectory Tool Development Activity What Is Low Thrust? Larry Kos MSFC Advanced Concepts Dept / TD30 Systems Analysis Team / TD33 6/9/2004
What Is Low Thrust? The thrust-to-weight (T/W0) ratio determines how long an in-space burn is to accomplish a particular DV. This is also the same as (initial) acceleration (a0). This determines if a mission (and its propulsion system) is considered low thrust or not. High thrust: -------> Short burn times: -------> T/W (a0): > ~0.1 g’s (Medium thrust: -------> Medium burn times: -------> T/W: ~0.12 g’s > a0 > ~0.002 g’s) Low thrust: -------> Long burn times: -------> T/W (a0): < ~0.001 g’s This leads to typical burn times (w/ m0 = 160 mt) for typical DVs of: Mission Isp Thrust DV Prop Mass Burn Time Accel: (sec) (lbf) (m/sec) (kg) (min) T/W0 (g's) TMI High Thr 461.3 74,250 3,887 92,241 210.21 TMI Med Thr 931.0 15,000 4,002 56,777 1290.043 TMI Low Thr 3931.0 76 7,622 28,704 54,6960.0002 (~10 MWe) (38 days) Larry Kos/MSFC/TD30 5/1/2003