Mean Time Between Failures (MTBF) is used to gauge which aspect of a space system?

Mean Time Between Failures (MTBF) is used to gauge which aspect of a space system?

• A. Propellant usage
• B. Reliability and expected time between failures
• C. Thermal margins
• D. Data bandwidth

Answer: (B)

Mean Time Between Failures is a reliability measure that tells you how long a system can be expected to operate before a failure occurs. It reflects the average uptime between failures and is used to plan maintenance, anticipate failures, and gauge the overall dependability of the spacecraft hardware or software. A higher MTBF means longer periods of normal operation between interruptions, which is exactly what reliability metrics aim to convey. It is not about how much propellant is used, the thermal safety margins, or the amount of data that can be sent; those describe resources and performance, not the frequency and timing of failures. For a system with a constant failure rate, MTBF is the inverse of that failure rate, giving a practical sense of expected operational life between failures.