[COSPAR]. Yesterday, 29 September, the COSPAR Panel on Planetary Protection (PPP) at its Executive meeting endorsed a proposed update to the Mars planetary protection policy, following a year-long consultation and a long-term process of engagement with the scientific community and stakeholders, including extensive discussions at recent Panel meetings, Workshops and Sessions at the 2026 COSPAR Scientific Assembly.
See Planetary Protection Directive From NASA Administrator Isaacman
The proposed update would introduce a Probabilistic Risk Assessment (PRA) framework alongside the existing prescriptive approach. Under the probabilistic pathway, missions would use mission-specific modelling of contamination pathways and controls to demonstrate that the probability of a contamination event does not exceed 1 × 10⁻⁴ per mission during the 50-year Period of Biological Exploration (PBE).
This represents an important evolution in planetary protection for future Mars missions, providing a risk-based pathway while maintaining the fundamental objective of protecting Mars and preserving the integrity of life-detection science.
The proposed policy update will now be submitted to the COSPAR Bureau for final approval and then be published in an upcoming issue of Space Research Today (SRT).
The meeting also welcomed new members to the Panel and reviewed a broad range of ongoing activities, including the publication of a new planetary protection policy for icy worlds earlier this year and several sessions and activities that occurred at the 2026 COSPAR Scientific Assembly in Florence.
Learn more about the COSPAR Panel on Planetary Protection: https://cosparhq.cnes.fr/scientific-structure/panels/panel-on-planetary-protection-ppp/
astrobiology
