Planetary protection, or the protection of celestial bodies from potentially harmful contamination, has been required by international law since the ratification of the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space in 1967. At that time, scientists were concerned about the potential of contaminating the Moon or bringing back a life form of lunar origin when astronauts returned to Earth with samples. The evidence is that the Moon does not contain indigenous life, but other celestial bodies may. Mars is of particular concern because of its habitability and plans to carry out a robotic sample return mission and even potentially human crewed missions in the near future (next 20–30 years). This article (recognizing that other national and international tasks are ongoing with detailed studies of technical aspects of containment and sample analysis) provides an overview of the policy aspects of planetary protection and sample return, discussing the history of planetary protection, lessons learned from the Apollo missions, and a potential strategy to ensure prevention contamination if a robotic sample return mission is carried out. It is recommended that the capability performed in the 1960s by the Interagency Committee on Back Contamination be reestablished, that regulations be developed to allow quarantine of anyone exposed to the samples, that scientific and technical personnel be trained in a receiving laboratory for at least 2 years prior to sample return, and that a test protocol be established for examining the samples. This will protect our biosphere while enabling groundbreaking research into conditions on Mars and any possible signs of life.

自1967年批准《国家探索和利用外层空间活动的原则条约》以来，国际法就​​一直要求保护行星或保护天体免受潜在有害污染的侵害。当宇航员带着样本返回地球时，担心污染月球或带回某种生命形式的月球起源的可能性。证据表明，月球不包含土著生命，但其他天体也可以。火星因其可居住性而特别引起关注，并计划在不久的将来（未来20至30年）执行机器人样本返回任务，甚至可能执行载人任务。本文（认识到其他国家和国际任务仍在进行中，正在对遏制技术和样本分析的技术方面进行详细研究）概述了行星保护和样本归还的政策方面，讨论了行星保护的历史以及从阿波罗中学到的经验教训任务，以及执行机器人样品返回任务时确保预防污染的潜在策略。建议重新建立机构间反污染委员会在1960年代的能力，制定法规以隔离任何接触样品的人，并建议科学技术人员在接收实验室中接受培训至少2年。在返回样品之前，应建立测试协议以检查样品。