Time dependence of the distance from the Sun to the TS and HP under the influence of the solar-cycle (SC – dashed line) and the LISM-fluctuation (LF – solid line) effects. Panel a: results for Voyager 1 and panel b – for Voyager 2. Green color shows results for the TS, and red/blue color – for the HP. Two HP definitions are used to test the generality of the simulation results.