AAE 450 Spring 2008

Allen GuzikJanuary 31, 2008

Trajectory

Airplane Launch Trajectory Code andΔV Drag Comparison

Trajectory Optimization 1/5

AAE 450 Spring 2008

Sample Airplane Launch

Trajectory Optimization

Trajectory Code Can Now Predict Orbits From an Aircraft Launch

Ascent Trajectory

Launch Site

Initial Height of 12,200 m

2/5

AAE 450 Spring 2008

ΔV Drag Comparison Purpose

– Attempt to validate how the trajectory code estimates drag

– Compare vehicle mass to Δv drag– Compare drag from different

launching configurations

Trajectory Optimization

Airplane, Balloon, Ground, Drag ΔV Comparison

Launch Type

GLOW [kg]

With Atmosphere Model No Atmosphere Model

ΔV Drag ΔV Total% ΔV Drag of

TotalΔV Drag ΔV Total

Airplane 29,023 75 9,918 0.76% 0 9,876

Airplane 5,593 215 11,295 1.90% 0 10,447

Balloon 5,593 14 2,911 0.48% 0 2,895

Ground 29,023 359 9,271 3.87% 0 10,677

Ground 5,593 932 10,154 9.18% 0 9,982

Assumptions– Same initial steering law

conditions– Orbit obtained is not considered– Same dimensions

Conclusions– Lighter Vehicle Increases Δv drag– Airplane and Balloon Launches decrease Δv drag– Trajectory Code handles drag appropriately, however the magnitude of the results

need to be verified.

Future Work– More analysis to further verify if Drag is being modeled correctly.

3/5

AAE 450 Spring 2008

Backup Slides

Trajectory Optimization

Sample Affect of Atmosphere on Ascent– Both Cases are for a GROUND LAUNCH

With Atmosphere No Atmosphere

4/5

AAE 450 Spring 2008

Backup Slides

Trajectory Optimization

Sample Balloon Ascent

30,500 m

5/5