Ground segment

In colder climates, electric heaters or hot air blowers may be necessary to prevent ice or snow buildup on the parabolic dish.

A single spacecraft may make use of multiple RF bands for different telemetry, command, and payload data streams, depending on bandwidth and other requirements.

Ground station tracking and ranging data are passed to the control center along with spacecraft telemetry, where they are often used in orbit determination.

Flight control software performs the initial processing of received telemetry, including: A spacecraft database provided by the spacecraft manufacturer is called on to provide information on telemetry frame formatting, the positions and frequencies of parameters within frames, and their associated mnemonics, calibrations, and soft and hard limits.

Commands may be issued manually in real time, or they may be part of automated or semi-automated procedures uploaded in their entirety.

As on-board computing power and flight software complexity have increased, there is a trend toward performing more automated data processing on board the spacecraft.

Staffing is typically greatest during the early phases of a mission,[3]: 21  and during critical procedures and periods, such as when a spacecraft is in eclipse and unable to generate power.

[16] Flight control software will typically generate notifications of significant events – both planned and unplanned – in the ground or space segment that may require operator intervention.

Mission-specific I&T provides an opportunity to fully test communications between, and behavior of, both the spacecraft and the ground segment prior to launch.

Reliability is a particularly important consideration for critical systems, with uptime and mean time to recovery being of paramount concern.

Costs associated with the establishment and operation of a ground segment are highly variable,[17] and depend on accounting methods.

According to a study by Delft University of Technology,[Note 1] the ground segment contributes approximately 5% to the total cost of a space system.

[19]: 10 Ground segment cost drivers include requirements placed on facilities, hardware, software, network connectivity, security, and staffing.

[20] Ground station costs in particular depend largely on the required transmission power, RF band(s), and the suitability of preexisting facilities.