The core feature of the Cape Town Convention is that it creates an interna-tional register of security interests over various categories of mobileassets, beyond the parameters of national law. There was clear interest insecuring creditors’ rights over certain types of mobile equipment –aircraft, rolling stock and spacecraft –because of their inherently trans-border operations. The response of the Convention and the individualProtocols was to introduce a sui generis registrable international interestfor each type of mobile stock that would be recognised by the contractingstates, avoiding national disparities in the event of default. The subject ofthis review is the Space Assets Protocol (SAP): three years on from thesigning of the SAP, support from new contracting States has been singu-larly absent. Nevertheless, discussions on the Protocol continue, as doesthe task of identifying a competent international authority, which is in aposition of taking over the function of a Supervisory Agency under theConvention.