Extreme space weather represents a hazard to the spaceborne technology upon which our society depends, including GPS navigation and satellite communications, and to human exploration of space. The development of models to predict that generation of high-energy particles arising from natural phenomena in space is critical to protect robotic and human assets in space. It is well known that a phenomenon known as shock-drift acceleration can accelerate particles to high energy at the bow shock of the Earth. Here numerical simulations and spacecraft observations are used to identify shock-drift acceleration and quantify the energy channeled into high-energy particles. The new capabilities introduced here lay the foundation for the future development of predictive models of particle acceleration at shocks within our solar system.