Yes, certain frequencies of radio waves can be blocked or attenuated by the Earth's atmosphere. The behavior of radio waves in the atmosphere depends on their frequency, and different frequency bands experience different levels of attenuation or absorption.
For example, certain radio frequencies in the microwave range, such as those used for satellite communication, can be affected by atmospheric phenomena like rain, fog, or atmospheric gases. Water droplets in the atmosphere can scatter or absorb microwave signals, leading to signal loss or degradation.
When communication is cut off between satellites or spacecraft and ground control stations, several methods can be employed to determine the status of the connection:
Telemetry Data: Satellites and spacecraft typically transmit telemetry data back to ground control stations. This data includes various parameters such as spacecraft health, status, and communication link information. Ground control stations continuously monitor and analyze this telemetry data to assess the status of the communication link. If the communication is lost, the absence of telemetry data or a sudden interruption in the received data can indicate the loss of connection.
Redundant Ground Stations: Ground control networks often consist of multiple stations distributed across different geographical locations. If communication is lost with a particular satellite or spacecraft from one ground station, other ground stations in the network can attempt to establish communication. The failure to establish communication from multiple redundant ground stations would indicate a more widespread issue.
Cross-Verification: Ground control stations maintain communication schedules with satellites or spacecraft. If a scheduled communication window is missed without any prior notification or expected downtime, it can be an indication of a communication failure. Ground control operators can cross-verify with other relevant parties, such as other mission control centers or international space agencies, to confirm if they are experiencing similar communication issues.
Ancillary Data Sources: In addition to telemetry data, ancillary data sources can provide insights into the status of the satellite or spacecraft. For example, radio astronomy observatories or amateur radio operators might detect signals from the satellite or spacecraft independently. If such external sources also report a loss of signal, it can help confirm the communication interruption.
When communication is lost between satellites or spacecraft and ground control stations, it often triggers investigations and diagnostic procedures to identify the cause of the communication failure. Troubleshooting efforts may involve analyzing telemetry data, checking hardware and software systems, evaluating the performance of ground-based communication equipment, and considering potential atmospheric or environmental factors that could affect the radio wave propagation.