Single-Event Lift Modulation Aerocapture for Small, Low-Cost Interplanetary Missions

Aerocapture has been shown to enable and enhance interplanetary missions, and it can be particularly beneficial for small, low-cost missions, as propulsive orbit insertion can be prohibitive for small planetary missions due to the mass constraints. This study investigates the use of single-event lift modulation aerocapture maneuvers to achieve efficient orbit insertion at planetary destinations such as Venus for small missions. Single-event lift modulation as a control method is implemented as a simpler control method other than bank modulation, drag modulation, or active force control. This paper focuses on the development and performance of the guidance algorithm and uses the Cupid's Arrow Mission Concept-a Nanosat concept to sample Venus' atmosphere [1]-as the baseline mission concept. The guidance uses a numerical predictor-corrector algorithm which is derived from the optimal control theory. A Monte Carlo simulation is used to compare and show the performance of the single-event lift modulation aerocapture. The study evaluates and compares the different lifting configurations to allow for the highest mass savings while ensuring a guaranteed safe capture. The analysis also includes the assessment of aerothermal heating environments from empirical relations developed by Sutton and Grave, dynamic pressure, and peak deceleration. The results show the benefits of single-event aerocapture as compared to propulsive orbit insertion for Cupid's Arrow. For an arrival hyperbolic velocity of 2.7 km/s at Venus, we can achieve 100% capture rate without crashes and escapes for a probe with a nominallift-to-drag (L/D) ratio of 0.2. The results also show a peak heat rate of 220 W /cm
²
which is well within the capability of the PICA TPS materials selected as the baseline of Cupid's Arrow.