Forty-nine years ago, the Holy See became a signatory to the Outer Space Treaty. On first blush, the Holy See becoming a signatory to the Outer Space Treaty may seem to be an enigma, but on closer examination there is a rationale for its participation.
Consider the legal effect of signature of an international treaty. Signature by a state demonstrates that it has agreed upon the content of the treaty, and expresses its intention to consider becoming legally bound to the treaty. Critically, the act of signature imposes a duty if not to be legally bound by the treaty, then to not act contrary to the treaty. This differs from the state ratifying or acceding to treaty in that both represent a willingness to be legally bound. To that extent, the signature of the Outer Space Treaty by the Holy See represents it has agreed upon the contents of the Outer Space Treaty and even though it may never ratify the accord, it does obligate the Holy See not to act contrary to it.
It’s likely the Holy See will never have a space program or participate in outer space activities, but being a signatory to the Outer Space Treaty allows the Holy See’s mission to the United Nations to be an informal observer to the Committee on the Peaceful Uses of Outer Space. This is consistent with the Holy See’s informal observer status in other bodies, including World Meteorological Organization in Geneva (WMO), International Strategy for Disaster Reduction (ISDR), International Maritime Organization (IMO), African Asian Legal Consultative Committee (AALCC) and the International Civil Aviation Organization (ICAO).
Aside from these, there are numerous other international bodies and agreements the Holy See has become a signatory to, including environmental pacts and international bodies. A discussion of some of the Holy See’s involvement can be found here.
Thus, while the Holy See’s signature of the Outer Space Treaty may at first pass provide an interesting space fact, a deeper look will show its participation has a pragmatic end as the world’s smallest nation.