SPORE Mission Design - Georgia Tech SSDL - Georgia Institute of ...

Altitude, km
For the 2U scenario, nominal entry trajectories were also designed to meet the constraints given in
Table 1. The LEO and GTO baseline trajectories are given in Table 11. Figure 13and Figure 16depict the
2x2U LEO and GTO trajectory profiles respectively. Figure 14 and Figure 17 show the maximum
acceleration the vehicle experiences over time. The maximum acceleration graphs demonstrates that
the 9g, 16g, and 40g loading constraints given in Table 1 are met. Figure 15 and Figure 18 give the
stagnation heat rate and dynamic pressure over time. The large increase in dynamic pressure during
parachute deployment is a property of the parachute model. The parachute is modeled as an infinite
mass which causes a sharp increase in deployment force and dynamic pressure. A higher fidelity
parachute model is underdevelopment.
Table 11: Baseline entry trajectory for 2U cases in spherical atmosphere relative coordinates.
R (km) Lon (°E) Lat (°N) V (m/s) γ (°) Σ (°)
LEO 6503.1 137.59 -14.85 7780.5 -5.04 183.0
GTO 6503.1 121.31 -40.89 9964.3 -6.23 57.8
The baseline entry trajectories in Table 10 and Table 11target Woomera, Australia at 31°12′0″S,
136°49′0″E. In order to reach Woomera from the GTO trajectory, a 2.5° inclination change will be
performed at apogee during the deorbit burn.
140
Altitude vs Velocity
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0
0 2000 4000 6000 8000
Velocity, m/s
Figure 13. 2x2U LEO trajectory profile.