A satellite has to operate in very harsh conditions after launch. Also, building a good satellite requires billions of dollars. Therefore it’s crucial to test each satellite properly before it enters space to ensure good performance and safety. This article covers the various types of satellites testing and challenges that may occur during the process.
Satellites, one of the long-existing inventions, are exhibiting their muscular and exuberant strength in the right way. For years, satellites have been providing services like navigation, communication, remote sensing, surveillance, earth observations, etc. Since satellites face lots of hazards in space during their operation, efficient technological standards are required to design them.
Today, most of the people depend on satellites in one way or the other, from GPS-based vehicles to weather forecasting to many other things in their lives. Currently, there are almost 1,500 active satellites in orbit around Earth.
Building a good satellite is not cheap. Government or private companies spend millions or even billions of dollars a year on satellites, and it would result in a heavy loss if a satellite fails during or following launch. So, tests and measurements play an important role in the case of satellites.
Tests and measurements are required for components of satellites manufactured for sub-systems and final assembly. Evaluating the performance of satellites is essential even on the ground station terminal. Such smart test and measurement solutions ensure good performance and reliable safety and security on every stage during a satellite launch.
Radio Check-Out Equipment (RF SCOE) (Credit: https://atos.net)
Inside the world of satellite testing
Extreme vibrations and high acoustic levels exist during satellite launch. Further, a satellite has to operate in very harsh conditions after launch. It has to function in a vacuum while handling high levels of electromagnetic radiation and fluctuation in temperatures.
Companies like NTS maintain a network of facilities across the US to conduct necessary tests to analyse how a satellite responds to a vacuum of space or extreme changes in temperature.
More tests are required for vibration, solar radiation, dealing with the dust of space, or pyroshock, which might occur during the booster separation stage or satellite separation stage from exploding bolts. Sometimes explosive shock might also occur during the booster separation stage. This can even damage circuits, lodge contaminants into satellites, or short circuit electrical components.
Other elements of a satellite that need testing during its construction, design, and payload include:
- Solar panels
- Electrical circuits
- Centre of gravity and mass measurements
- Information transmitting systems from satellite to the ground station
- Fuel cells
Currently, NASA and other private companies are trying to build smaller vehicles that would be capable of repairing satellites. NASA is also working on ideas that would help assemble satellites in space itself.
The satellite’s assembly team is the first group to test it. Next, a quality control team conducts a separate series of tests. The team often repeats many of these tests to gather enough data to decide whether or not the satellite is fit to go into orbit.
Testing has to be carried out in a clean room. Scientists and engineers involved in testing can be usually seen wearing a white suit. A clean room or environment is an integral part of satellite testing because one tiny outside contaminant can produce a drastic effect on a satellite.
The United Launch Alliance Atlas V rocket stands ready for liftoff with NOAA’s GOES-S satellite on Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida (Credit: NASA)
The two major satellite tests are as follows:
Antenna deployment test
The uplink/downlink commands and telemetry data are established once the satellite antenna is perfectly deployed in space. So, for establishing reliable communication between the ground control station and satellite, this test is essential.
It involves activities such as battery voltage and bus voltage testing, primary and secondary battery voltage testing, solar panel voltage testing, actuator and sensor testing, momentum wheel testing, magnetic voltage testing, sun sensor testing, etc.
Testing story of GOES-S
National Ocean and Atmospheric Administration tested its Geostationary Operational Environmental Satellite-S (GOES-S), a weather satellite, in March