A simplified trajectory analysis model for small satellite payload recovery from low Earth orbit

Abstract

The reentry trajectories of a small mass at low Earth orbit were analyzed with a modified three degree-of-freedom trajectory simulation. An estimate of the stagnation point heating was also made. The mass deployed an inflatable, three-element drag disk decelerator that was modeled as a single circular disk, trailing the payload, normal to the direction of flight. The downrange distance decreased and the time of flight increased with increased decelerator area. The stagnation-point heat transfer rates with a decelerator of sufficiently low ballistic coefficient of 24 Pa was 5–10 percent that of a typical ballistic reentry vehicle with a ballistic coefficient of 4.8 kPa. The study did not find that staged deployment of the decelerator disks provided any aerodynamic advantages, particularly in view of the anticipated complexities involved in deploying such a system. Finally, skip trajectories yielded slightly lower stagnation-point heat transfer than the non-lifting case. However, they may not be advantageous since the increased flight time would expose the decelerator to a longer period of heating, thereby possibly requiring more extensive thermal protection and a potential to damage on-board sensors and instruments.