Abstract:
Starting with the Apollo missions, precious lunar and asteroid samples have been brought back to Earth. Specific facilities have been designed to curate and to study these samples. These facilities focus on maintaining the samples as shielded as possible from any source of contamination, but do not take into account a potential biohazard, since the bodies that have been sampled are known to be devoid of life or traces of life. However, with the plan of Mars sample return missions in the next decades, the scientific community will have to deal with samples from worlds that may bear past or present life. To prevent cross-contamination between Earth and other solar system objects (see the Outer Space Treaty, 1967), extra care will have to be taken while designing the sample return mission, and especially when samples are brought back to Earth.

The EURO-CARES (European Curation of Astromaterials Returned from Exploration of Space) multinational project funded under the European Commission's Horizon2020 research programme (www.euro-cares.eu) aims at designing a facility to receive, contain, and curate extraterrestrial samples with or without biohazard, from various sample return missions. This facility will provide a clean environment to store and study samples, while guaranteeing terrestrial planetary protection. For samples from Mars and other potentially habitable worlds, a portion of the returned samples will be devoted to life detection. Biohazard assessment protocols (BAP) will be a core activity of the facility, a necessary step to assess whether the samples can leave containment (i.e., there is no evidence of life) or not. Designing such a European Extraterrestrial Sample Curation Facility (ESCF) raises a lot of issues and questions for and from the scientific community: What are the best conditions to curat!
e samples from Mars to keep them as pristine as possible? What kind of tests/experiments, destructive or not, have to be conducted to assess the presence of (potentially harmful living) extraterrestrial organisms in the returned samples? How much of the limited amount of available samples should be used for these tests to obtain reliable results? If there is "life" in the samples, should they be sterilized to allow sample distribution to the scientific community, or should (all) the investigations be conducted inside the ESCF? Since the type of life we may encounter is still unknown, what kind of sterilization and decontamination techniques should be installed in the facility (autoclave, chemical showers,...)?

For samples returned from Mars, detection of life is a very important topic, not only in terms of the "planetary protection perspective" (i.e., these samples are regarded as having the potential of containing life or signatures of life), but in the "science perspective" (i.e., to know whether life ever arose on Mars). Accordingly, specific and appropriate handling and analysis of these samples will be required.

To answer some of these crucial questions and others that will arise, we are looking forward to the input and expertise from planetary scientists, in particular from the astrobiology community, as well as from biosafety laboratories, cleanroom manufacturers, electronics and pharmaceutical companies, nuclear industry, etc.