In space science and engineering, what is the measurement of physical quantities at remote distances by means of a radio link from the moving object to the ground station called?

Introduction / Context:
Modern space missions, missiles, aircraft, and even remote environmental monitoring systems often operate far away from human observers. Engineers still need to measure important physical quantities such as temperature, pressure, speed, and orientation in real time while the object is in motion. To do this, instruments on board the object send data back to a ground station using radio signals. This science and technology of measuring at a distance through such radio links has a specific name, and this question asks you to identify that term from the options given.

Given Data / Assumptions:
- Measurements are taken at a remote location, not directly by an observer standing at the object.
- Data such as pressure, temperature, or voltage are converted to electrical signals onboard the object.
- These signals are transmitted over a radio link to a receiving station on the ground.
- The term must refer to measurement at a distance, not just general communication or imaging.

Concept / Approach:
The key concept is measurement at a distance by electronic means. The word part tele means distance, and metry refers to measurement. Together they form the word telemetry, which literally means distance measurement. In telemetry, sensors convert physical quantities into electrical signals, which are encoded and transmitted by radio to the ground. The ground system decodes and records the measurements. This is different from general telecommunication, which may transmit voice or data without necessarily focusing on measured physical quantities, and different again from radar ranging or photogrammetry, which are specific techniques of distance or image measurement.

Step-by-Step Solution:
Step 1: Highlight the important phrase in the question, measurement at remote distances by means of a radio link. Step 2: Recognize that the prefix tele suggests distance, and the root metry suggests measurement. Step 3: Look at option A, telemetry, which exactly matches the idea of remote measurement via electronic signals. Step 4: Consider option B, telecommunication, which refers more broadly to the transmission of information such as voice or data, not specifically to measurement. Step 5: Note that option C, telepathy, is a term from parapsychology and does not involve scientific radio links. Step 6: Assess option D, radar ranging, which measures distance by sending and receiving radio waves but does not describe a general system of transmitting many different measured quantities. Step 7: Assess option E, photogrammetry, which uses photographs to measure shapes and positions, not radio telemetry. Step 8: Conclude that telemetry is the correct term.

Verification / Alternative check:
As an additional check, think about descriptions of space missions in documentaries or textbooks. They often mention that mission control receives telemetry from the spacecraft, which includes measurements from many onboard instruments. Engineers in mission control watch the telemetry to ensure that the spacecraft remains healthy and on course. The same word is used in other fields such as weather balloons and remote monitoring of pipelines. These examples confirm that telemetry is the appropriate term for remote measurement by radio link.

Why Other Options Are Wrong:
Telecommunication, option B, involves transmitting information over distance but does not specifically refer to the process of measurement and is therefore too broad.
Telepathy, option C, is a popular term for supposed mind to mind communication and has no relation to scientific radio based measurement systems.
Radar ranging, option D, is a specialized method that uses reflected radio waves to measure distance, not a general framework for sending many kinds of measured data from a moving object.
Photogrammetry, option E, deals with measurements from photographs, often in mapping and surveying, and does not involve a live radio link with sensors on a distant moving object.

Common Pitfalls:
A common error is to choose telecommunication because it sounds familiar and also includes the prefix tele. However, telecommunication describes the broad field of communication over distance and not specifically measurement. Another pitfall is confusing telemetry with radar, as both involve radio waves, but radar focuses on detection and ranging, while telemetry focuses on transmitting measured values. Learners should pay close attention to the word parts and the functional description in the question to avoid these confusions.

Final Answer:
Telemetry is the correct term for the measurement of physical quantities at remote distances by means of a radio link from the object to the ground station.