During the entire launch sequences from liftoff to final orbital insertion of a space vehicle (SV), adequate link requirements are to be maintained for telemetry, tracking, and command (TT&C) for uplink and downlink services, from launch vehicle (LV) and SV to ground stations (GS). A successful space vehicle launch required adequate link coverage with good radio frequency (RF) performance. The chapter is an extension of the IEEE/Aerospace Conference 2019 paper entitled Dynamic Link Analysis and Application for a MEO Space Vehicle published by the authors. The emphasis in this chapter is on the addition of the three distinctively different tracking waveforms and their associated links, used from liftoff to final orbital insertion. This chapter will describe the three required dynamic link analyses (DLA) to cover (a) the LV link from liftoff to its end of line of sight (LOS), (b) the LV link from LOS to Tracking and Data Relay Satellite System (TDRSS) at beyond line of sight (BLOS), and (c) the final tracking link using Space-to-Ground Link Subsystem (SGLS) or non-SGLS (NSGLS) link for the earliest or best separation time of the SV from the LV. The chapter discusses the concept of the dynamic link analysis, SV antenna switching schedule, recommended SV separation time, as well as the performance for different launch scenarios within the 24-h launch window. Topics include antenna patterns, launch trajectories, elevation angle and clock and cone angle geometry, and dynamic link budget.
Part of the book: Satellite Systems