making can be even more severe. The presence of additional approval layers can hinder the ability of a project to respond to changes in performance and cost that often occur during the development of a facility. Legal requirements such as the U.S. International Traffic in Arms Regulations (ITAR) can add significant delays and costs. Finally, international commitments can make it much more difficult to terminate or descope projects but can also smooth out funding profiles if partners are able to contribute at different times or rates. Overall, the implied financial stability of government agency involvement can be a double-edged sword.
An alternative approach to partnership is to coordinate access across a suite of facilities. In this model, individual parties build or operate an instrument or facility but access and/or data rights are shared with partner communities. A more limited form of partnership is the sharing of archival data from a facility, even in cases where observing time is restricted. Other arrangements may prove to be just as effective. For example, access to both the northern and southern skies is essential for many areas of astronomy; a partnership could take the form of time swaps on solely owned telescopes in the two hemispheres. Likewise, one international partner might have a unique facility (e.g., the proposed Large Synoptic Survey Telescope), and access to its observing time or data could be traded for access to other unique facilities (e.g., VLT or E-ELT). The key advantage of such arrangements is that