Ballistic Capture Dynamics and Trajectory Optimization for Observation of Enceladus

Enceladus, a cryovolcanic moon of Saturn, presents a high-priority target for astrobiological investigation due to its subsurface ocean and hydrothermal activity. However, traditional high-thrust orbital insertion into the deep Saturnian gravity well imposes severe propellant penalties, limiting scientific payload capacity. This study investigates a low-energy mission architecture utilizing ballistic capture mechanisms within the Circular Restricted Three-Body Problem (CR3BP) framework. By exploiting the Weak Stability Boundary (WSB) and invariant manifolds associated with the Lagrange points (L1 and L2), we identify transfer pathways that minimize deterministic ∆V . An analysis of seven interplanetary transfer strategies was conducted, comparing direct transfers against complex gravity assist sequences. Numerical simulations utilizing MATLAB’s ode45 integrator indicate that a Cassini-like Venus–Venus–Earth–Jupiter Gravity Assist (VVEEGA) trajectory, combined with ballistic capture, reduces the total mission ∆V to approximately 5.09 km/s, compared to 7.75 km/s for a direct transfer. This reduction in ∆V validates the feasibility of using chaotic gravitational dynamics to enhance mass fractions for deep-space orbiters.