Editing Telemetry (section)

==={{anchor|Defense, space and resource exploration systems}}Defense, space and resource exploration===
Telemetry is used in complex systems such as missiles, RPVs, [[spacecraft]], [[Oil platform|oil rig]]s, and [[chemical plant]]s since it allows the automatic monitoring, alerting, and record-keeping necessary for efficient and safe operation. Space agencies such as [[NASA]], [[ISRO]], the [[European Space Agency]] (ESA), and other agencies use telemetry and/or telecommand systems to collect data from spacecraft and satellites.

Telemetry is vital in the development of missiles, satellites and aircraft because the system might be destroyed during or after the test. Engineers need critical system parameters to analyze (and improve) the performance of the system. In the absence of telemetry, this data would often be unavailable.

====Space science====
Telemetry is used by crewed or uncrewed spacecraft for data transmission. Distances of more than 25.1 billion kilometers (May 2025)<ref>https://www.theregister.com/2025/05/15/voyager_1_survives_with_thruster_fix/</ref> have been covered, e.g., by [[Voyager&nbsp;1]].

====Rocketry====
In rocketry, telemetry equipment forms an integral part of the [[rocket range]] assets used to monitor the position and health of a launch vehicle to determine range safety flight termination criteria (Range purpose is for public safety). Problems include the extreme environment (temperature, acceleration and vibration), the [[energy supply]], [[Antenna (radio)|antenna]] alignment and (at long distances, e.g., in [[spaceflight]]) signal [[time of flight|travel time]].

===={{anchor|Flight test}}Flight testing====
Today nearly every type of [[aircraft]], [[missile]]s, or [[spacecraft]] carries a wireless telemetry system as it is tested.<ref>“Foster, Leroy." "Telemetry Systems", ''[[John Wiley & Sons]]'', New York, 1965.</ref> Aeronautical mobile telemetry is used for the safety of the pilots and persons on the ground during flight tests. Telemetry from an on-board [[flight test instrumentation]] system is the primary source of real-time measurement and status information transmitted during the testing of crewed and uncrewed aircraft.<ref>”  ITU-R M.2286-0 Operational characteristics of aeronautical mobile telemetry systems”, ''[[International Telecommunication Union]]'', Geneva 2014.</ref>

===={{anchor|Enemy intelligence}}Military intelligence====
Intercepted telemetry was an important source of intelligence for the United States and UK when [[Soviet Union|Soviet]] missiles were tested; for this purpose, the United States operated a listening post in [[Iran]]. Eventually, the Russians discovered the United States intelligence-gathering network and encrypted their missile-test telemetry signals. Telemetry was also a source for the Soviets, who operated listening ships in [[Cardigan Bay]] to eavesdrop on UK missile tests performed in the area{{Citation needed|date=May 2024}}.