Inflatable devices could slash fuel costs for Mars and Venus missions

Future missions to Mars and Venus aim to save fuel by using atmospheric drag for orbital insertion—a technique called aerocapture—rather than relying solely on propulsion. While aerobraking (gradual orbit lowering) has been flown, aerocapture requires a single, precise pass through the atmosphere. Philippe Reynier's survey (arXiv:2605.26125) catalogs inflatable devices—ballutes, sails, and inflatable heat-shield capsules—that could enable this maneuver. These structures deploy after entry, increasing drag surface area to slow the spacecraft without additional propellant.

The paper emphasizes the tight guidance, navigation, and control needed for aerocapture: even a small density variation can destroy the vehicle. It also reviews existing test data and flight heritage, noting that no full-scale aerocapture demonstration exists despite promising concepts like the Mars Premier project. For engineers and mission planners, the survey consolidates state-of-the-art trade-offs between mass savings, thermal protection, and maneuver accuracy—critical for enabling heavier scientific payloads to the inner planets.