Potential users should become familiar with TDRSS capabilities and constraints, which are detailed in the SNUG, as early as possible. This action allows the user to evaluate the trade-offs available among various TDRSS services, spacecraft design, operations planning, and other significant mission parameters. It is recommended that potential users contact the NIMO as early as possible for assistance in performing the trade studies. When these evaluations have been completed, and the user desires to use TDRSS, the user should initiate a request for TDRSS service.

Initial requests for TDRSS service from non-U.S. Government users shall be addressed to SCaN at NASA Headquarters, as follows: Deputy Associate Administrator: Space Communications and Navigation Division, National Aeronautics and Space Administration, Washington, DC 20546.

Upon review and acceptance of the service request, preliminary analyses shall be performed to determine the feasibility of meeting the proposed requirements.

If the request is determined to be feasible, the user and SCaN shall negotiate an agreement for provision of the requested services. Acceptance of user requests for TDRSS service is the sole prerogative of NASA.

Upon approval of the agreement by both parties, GSFC will be assigned to produce the detailed requirements, plans, and documentation necessary for support of the mission. Changes to user requirements shall be made as far in advance as possible and shall be submitted, in writing, to both SCaN at NASA Headquarters (see Section 108, paragraph (a) for mailing address) and GSFC, as follows: Chief: Networks Integration Management Office, Code 450.1, NASA Goddard Space Flight Center, M/S 450.1, 8800 Greenbelt Road Greenbelt, MD 20771.