Human Space Flight

Simulating Supersonic Parachute Inflation for Atmospheric Entry

Image from simulation showing pastel-colored simulation of a vehicle parachute during atmospheric entry
Video of a fluid-structure interaction simulation of the third ASPIRE flight test, showing density on the cut plane, payload, and parachute surface to highlight bow shock and low density in the wake. Suspension lines, gap lines, and vent lines are shown in white. The payload and parachute are moving steadily at nearly twice the speed of sound and are held rigid until time 0, after which the parachute is allowed to deform and the system allowed to decelerate. Francois Cadieux, Michael Barad, NASA/Ames

Over the next decade, NASA has planned three interplanetary robotic exploration missions that will require the use of supersonic parachutes during their landing phase: Mars Sample Return (Mars, 2028), DaVinci (Venus, 2031), and Dragonfly (Titan, 2034). The agency’s Entry Systems Modeling project is funding research and development toward improving our understanding of the complex physics surrounding parachutes and our ability to predict their behavior during inflation, where parachutes are under the most stress and most likely to fail. As part of this effort, the Launch, Ascent, and Vehicle Aerodynamics (LAVA) team at NASA’s Ames Research Center is developing the capability to computationally simulate supersonic parachute inflation, continuing an iterative process of validation where they perform several fluid-structure interaction (FSI) simulations of the Advanced Supersonic Parachute Inflation Research Experiments' (ASPIRE) third flight test, called SR03, and compare simulation predictions to the flight test measurements. The SR03 test was conducted in the upper Earth atmosphere in 2018, and it helped to certify the parachute used by Mars Perseverance, which landed on Mars in 2021.

Quick Facts

Access to the NASA Advanced Supercomputing facility’s resources allows us to quickly iterate on the details of physics-based models used in simulating the complex fluid-structure interactions that occur during supersonic parachute inflation, and turn around meaningful solutions to flight projects on a mission-relevant timeline.

Aaron Brandis,
Entry Systems Modeling Principal Investigator,
NASA Ames Research Center
  • The LAVA simulations model approximately 0.8 seconds of real-world time, during which the parachute inflates fully, closes slightly, re-opens, and finally reaches its “steady” descent state. Each simulation typically uses 50 Skylake nodes (2,000 cores) on the Electra system at the NASA Advanced Supercomputing facility for roughly 48 hours, accumulating roughly 30 terabytes of volume and surface data.
  • The team found that by improving the level of fidelity of the simulation and incorporating the parachute and vehicle’s deceleration, they saw a 12% drop in the predicted force the parachute exerts on the payload (pull force), and were able to obtain better agreement with flight measurements, demonstrating the importance of modeling the system’s deceleration for supersonic parachute inflation.
  • Best practices developed by the LAVA team for these simulations will inform future work for upcoming missions where flight test data may not yet be available and where FSI predictions can complement other data and models in the design process to ultimately reduce risks to the mission.
  • The team is continuing to develop the LAVA FSI tool by adding related physics-based models to enhance its predictive capabilities and optimize its runtime efficiency, so the tool can be used to inform future interplanetary robotic missions.

Researchers

  • Francois Cadieux, NASA Ames Research Center
  • Michael Barad, NASA Ames Research Center

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