Slowing down requires a thermal shield, two main parachutes – each with its own pilot chute for extraction – and a retro-rocket propulsion system triggered 20 seconds before touching the martian surface.

Most of the supersonic velocity will decrease due to the aerodynamic drag of the capsule. The most efficient way to remove the remaining speed for a safe landing is with a combination of parachutes and retro-rockets.

“Using two parachutes allows us to design a strong, medium-sized parachute to decelerate the probe through supersonic speeds and then a much larger, lightweight parachute for the final descent,” explains John Underwood, principal engineer at Vorticity, the UK company entrusted with parachute design and test analysis.

The first stage main parachute is 15 m-wide, similar to the type of parachutes designed for landing NASA’s Viking Mars spacecraft in 1972. For ExoMars, teams are using a variant designed for the successful ESA Cassini-Huygens mission to Titan, Saturn’s largest moon. This three-stage parachute system still holds the record for the most distant landing from Earth ever attempted.