Watch ESA’s Mars chief engineer Albert Haldemann explain the sterilisation process of one of the parachutes of the ExoMars Rosalind Franklin rover mission and why it matters.

Carefully wrapped inside a donut-shaped bag is a 35-m diameter parachute, about to be baked inside a specialised dry-heat steriliser oven. The parachute needs to be at least 10 000 times cleaner than your smartphone.

To get rid of any microbes it might have picked up during its time on Earth, the parachute was heated up in a specialised oven at the European Space Agency’s Life Support and Physical Sciences Laboratory at ESTEC, the agency’s technical centre in the Netherlands. All air inside the cleanroom continuously passes through a two-stage filter, and everyone entering the chamber must gown up more rigorously than a surgeon before passing through an air shower to remove any contaminants.

The 74 kg parachute, made mostly of nylon and Kevlar fabrics, will endure a six-minute dive into the thin martian atmosphere and slow down the ExoMars Rosalind Franklin rover for a safe landing on the Red Planet. This feat will make it the largest parachute ever to fly on the Red Planet, or anywhere else in the Solar System besides Earth.

The ExoMars Rosalind Franklin rover mission will launch in 2028 and spend over 25 months travelling to the Red Planet where it will search for signs of life beneath the martian surface.

The potential existence of past and perhaps even present-day life on our closest planetary neighbour requires rigorous sterilisation, to make sure that no microbes piggyback their way there from Earth. Any terrestrial microbes hardy enough to survive the ride through space could interfere with the investigation by causing ‘forward contamination’ and triggering a false positive.

Protecting the martian environment from ourselves, in accordance with international planetary protection measures, is as important as protecting the mission itself.