Electronics & Avionics Flashcards

What is 'apogee delay' and why might a flyer enable it on their altimeter?

Answer: A brief pause after apogee detection before firing the drogue, to confirm the rocket is truly descending

Apogee delay adds a short wait after the pressure sensor detects apogee to confirm the rocket is actually descending, reducing false fires from pressure fluctuations.

When an altimeter is described as 'MACH immune' or 'MACH lockout capable,' what problem does this feature address?

Answer: It locks out apogee detection during transonic flight where shock waves cause false pressure readings

Transonic and supersonic shock waves cause pressure spikes that can mimic apogee; Mach lockout disables apogee detection until the rocket slows to subsonic speed.

What does a flyer typically verify during a 'pyro continuity check' on the launch pad?

Answer: That each pyro channel shows a continuous circuit through its connected e-match

Continuity checks confirm that each firing circuit has an unbroken electrical path through the e-match, ensuring the altimeter can fire the charge when commanded.

What is the advantage of using a telemetry-capable altimeter that transmits live data to the ground?

Answer: It allows the flyer to monitor altitude, velocity, and event status in real time during flight

Live telemetry lets the flyer see real-time altitude, velocity, and pyro event confirmations, helping diagnose deployment issues immediately after flight.

Why must avionics bay vent holes have a combined area proportional to the bay volume in HPR design?

Answer: Sufficient vent area ensures the internal pressure equalizes with ambient quickly for accurate altitude sensing

Vent holes must be large enough to allow rapid pressure equalization so the barometric sensor reads true ambient pressure without lag-induced errors.

What is the role of a 'flight computer' that includes an accelerometer in addition to a barometric sensor?

Answer: It provides inertial data for motor staging, boost detection, and fusing with pressure data for more robust event detection

Combining accelerometer data with barometric readings allows the flight computer to detect boost phase, staging events, and improve reliability of apogee and landing detection.

According to safe HPR electronics practice, when should the avionics bay be powered ON at the launch site?

Answer: After the rocket is on the launch rail and all personnel are a safe distance away

Avionics should be powered on only after the rocket is on the rail and bystanders are clear, minimizing the time an armed system is present among people.