Key facts
- An analysis of European Space Agency missions finds that planetary protection costs for category IV Mars landings are estimated at up to approximately 5 percent of total mission cost.
- An analysis of European Space Agency missions finds that planetary protection costs for category III orbiters to Mars and icy worlds are estimated at less than 1 percent of total mission cost.
- An analysis of European Space Agency missions finds that missions to planetary protection category I and II target bodies require no supplementary investments or manpower.
- Planetary protection investments aim to keep spacecraft from spreading harmful contamination through the solar system and to shield Earth's biosphere from dangerous extraterrestrial material.
Astrobiology Web published an analysis on Nov. 14, 2026, finding that planetary protection for European Space Agency category IV Mars landings costs up to approximately 5 percent of total mission cost.
Astrobiology Web reported that planetary protection investments aim to keep spacecraft from spreading harmful contamination through the solar system and to shield Earth’s biosphere from dangerous extraterrestrial material. The paper calls the first aim forward planetary protection, meaning the prevention of contamination of other solar system bodies, and the second backward planetary protection, meaning the guarding of Earth from extraterrestrial material. Those two categories structure the cost assessment.
Astrobiology Web reported that missions to planetary protection category I and II target bodies require no supplementary investments or manpower. The evaluation covers European Space Agency missions since the agency’s first deep-space exploration in 1985 and separates forward protection costs by mission type and target body. The lowest-cost category applies to target bodies with little relevance for planetary protection, where no additional financial or staffing burden is needed.
For restricted Earth-returned sample missions under backward planetary protection category V-r, Astrobiology Web reported that the analysis treats the entire mission as a planetary protection effort rather than a mission with an additional cost. Returning samples could release unwanted material into Earth’s biosphere, so safety must be built into the mission from the outset. The potential release makes safety integral to the mission rather than an extra expense.
Astrobiology Web reported that planetary protection implementation has at times been seen as a cost driver for projects, a perception that motivates the analysis. The study evaluates actual European Space Agency mission costs to test whether planetary protection requirements are prohibitively expensive from the agency’s perspective.
The cost analysis appears within the theme issue “Planetary Protection for sustainable space exploration.” Astrobiology Web reported that the article is part of a broader collection of articles on planetary protection, treated as part of a coordinated scholarly issue on sustainable space exploration.
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