| Time (approximate)
| Activity
| Project conceptualization (At least 3 years before launch; Ref. § 1215.108(a)) | Request NASA Headquarters perform study to determine availability of TDRSS. If accepted as a user, begin contractual negotiation by submission of $25,000 non-refundable charge, and place into mission model.
| 3 years before launch (Ref. § 1215.109(c). | Submit general user requirements to permit preliminary planning. Begin payment for pre-mission activities (Ref. § 1215.115(b)(5)).
| 18 months before launch (earlier if interfacing is expected). | Provide detailed requirements for technical definition and development of operational documents and ICD's. (Ref. § 1215.109(e)). If appropriate, initiate action with the Federal Communications Commission for license to communicate with TDRSS at least 18 months prior to launch (Ref. § 1215.107(b)).
| 3 weeks prior to a scheduled support period (SSP). 2 weeks prior to an SSP | Submit scheduling request to GSFC covering a weekly period. Receive schedule from GSFC based on principles of priority (Ref. § 1215.109(b)(2)). Acknowledgement to GSFC required.
| Up to 12 hours prior to an SSP. | Can cancel an SSP without charge (Ref. § 1215.113(a)(1)).
| Up to 45 minutes prior to an SPP. | Can schedule an SSP if a time slot is available without impacting another user.
| Between SSP minus 45 minutes and the SSP. | Schedule requests will be charged at the disruptive update rate (Ref. § 1215.109(b)(5)).
| Real-Time. | Emergency service requests will be responded to per the priority system (Ref. § 1215.109(b)(3)) and assessed the emergency service rate. |
