4000 + 3500 ◆Biprop 3000 +Cryo A Electric 2500 x Nuclear 留 2000 芭 AA 1500- XX X 1000 A△ 500. 0 0.0 0.2 0.4 0.6 0.8 1.0 Utility(dimensionless) Fig.4.Trade space for nominal user,with propulsion system indicated 4000 4000 3500 3500 +Low Capabaity Medium Capability Medium Capability 3000 △High Capablity 3000 △High Capablity x Extreme Capabality x Extreme Capabality 2500 2500 2000 2000 1500 1500 1000 44 1000 500 500 0 0 0.0 0.2 0.40.60.8 1.0 0.0 0.2 0.40.6 0.8 1.0 Utility(dimensionless) Utility(dimensionless) Fig.5.Trade space for nominal user,with capability Fig.6.Trade space for capability stressed user indicated American Institute of Aeronautics and Astronautics5 American Institute of Aeronautics and Astronautics 0 500 1000 1500 2000 2500 3000 3500 4000 0.0 0.2 0.4 0.6 0.8 1.0 Utility (dimensionless) Cost (M$) Biprop Cryo Electric Nuclear 0 500 1000 1500 2000 2500 3000 3500 4000 0.0 0.2 0.4 0.6 0.8 1.0 Utility (dimensionless) Cost (M$) Biprop Cryo Electric Nuclear Fig. 4. Trade space for nominal user, with propulsion system indicated 0 500 1000 1500 2000 2500 3000 3500 4000 0.0 0.2 0.4 0.6 0.8 1.0 Utility (dimensionless) Cost (M$) Low Capability Medium Capability High Capablity Extreme Capability Fig. 5. Trade space for nominal user, with capability indicated 0 500 1000 1500 2000 2500 3000 3500 4000 0.0 0.2 0.4 0.6 0.8 1.0 Utility (dimensionless) Cost (M$) Low Capability Medium Capability High Capablity Extreme Capability Fig. 6. Trade space for capability stressed user