Spacecraft Design and Sizing Dr Andrew Ketsdever MAE

Spacecraft Design and Sizing Dr Andrew Ketsdever MAE 5595 Lesson 14

Spacecraft Design and Sizing Introduction • Big Picture: The Mission drives the Payload and the Orbit, which drives the Spacecraft Design

Spacecraft Design and Sizing Overview of Spacecraft Design & Sizing

Spacecraft Design and Sizing Principal Requirements & Constraints for S/C Design

Spacecraft Design and Sizing Principal Requirements & Constraints for S/C Design

Spacecraft Design and Sizing Weight Budget

Spacecraft Design and Sizing Spacecraft Configuration Drivers

Spacecraft Design and Sizing • Can use historical data for next block of same S/C, or to generalize within a mission type

Spacecraft Design and Sizing Mass Distribution for Selected Satellites

Spacecraft Design and Sizing

Spacecraft Design and Sizing Mass Distribution for Selected Satellites

Spacecraft Design and Sizing Top-Down Sizing Example • Given: navigation mission with m. P/L = 50 kg • Find: subsystem masses and mdry

Spacecraft Design and Sizing Top-Down Sizing Example • Still need other masses to permit eventual launch vehicle choice • mkick is apogee kick motor – if needed • madapter counts against booster performance #s • Need to include margin

Spacecraft Design and Sizing S/C Budgets • For top-down designs, allocate so much of a quantity or capability to each subsystem • Types of budgets – – – – Mass Power Communication bandwidth Volume Reliability Pointing error Cost Schedule, etc

Spacecraft Design and Sizing Mass Budget • See previous navigation S/C example → Now add mass margin into calculation • Margin covers the uncertainty in our estimates – Typical range from 5% to 25% – Larger margin for new S/C, or earlier in design phase – Smaller margin for known S/C, or as design progresses

Spacecraft Design and Sizing Preparing a Power Budget

Spacecraft Design and Sizing Typical Power Consumption by Module or Subsystem

Spacecraft Design and Sizing Propellant Budget • List v’s • Use ideal rocket equation to convert v to propellant mass

Spacecraft Design and Sizing Propellant Budget

Spacecraft Design and Sizing Estimating Spacecraft Equipment Compartment Dimensions