"""
Maximum ΔV that a spacecraft can impulse for a given single time step
"""
function max_ΔV(duty_cycle::Float64,
                num_thrusters::Int,
                max_thrust::Float64,
                tf::Float64,
                t0::Float64,
                mass::Float64)
  return duty_cycle*num_thrusters*max_thrust*(tf-t0)/mass
end