Introduction

There are a number of primary space research service (SRS) allocations that can be used by deep-space missions for telecommand, telemetry, and radiometric data collection. Some of these allocations are designated specifically for deep-space SRS missions and are not available to non-deep-space SRS missions, while other allocations are available to both deep-space and non-deep-space SRS missions.

The above primary SRS allocations are restricted to deep-space missions and are not available to non-deep-space missions. These allocations together provide a total of 555 MHz in the Earth-to-space direction and 560 MHz in the space-to-Earth direction.

In addition to these primary deep-space allocations in Table 1, there are two other general primary SRS allocations of 37-38 GHz (space-to-Earth) and 40-40.5 GHz (Earth-to-space). Since the 37.5-38 GHz part of the 37-38 GHz band is shared with FSS, it is not especially usable for deep-space missions, especially for manned planetary missions.

The use of the 2 110-2 120 MHz (Earth-to-space) band will be limited in the future at NASA's Madrid Deep-Space Communication Complex due to potential interference to IMT-2000 users. The 8 400-8 450 MHz (space-to-Earth) band is very congested, since it is being extensively used by all deep-space missions. The 34.2-34.7 GHz (Earth-to-space) and 31.8-32.3 GHz (space-to-Earth) allocations are not yet crowded, but deep-space missions have started using these bands. Currently, there are no known deep-space missions planning to use the 37-38 GHz (space-to-Earth) and the 40-40.5 GHz (Earth-to-space) allocations, and the ground infrastructure needed to support these frequencies has yet to be developed.