Before entering XRPS, users should first assess the technical feasibility of the intended observations, based on the available information (primarily the UHB) and tools from the SOC web server at the URL http://astro.estec.esa.nl/XMM/.
Based on the feasibility calculations a scientific justification should be prepared, following the Policies and Procedures for AO-1, which are available via anonymous ftp or web browser at the URL ../../../ao1.html.
This will be included in the online submission of the proposal using XRPS (§ 5.8).