cnotes11

75 seconds after h0 backup sri detects an internal

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: mmand Booster Nozzles Main engine Nozzle Diagnostic and flight information D SRI Measures attitude of launcher and its movements in space C Horizontal velocity Backup SRI Measures attitude of launcher and its movements in space; Takes over if SRI unable to send guidance info Strapdown inertial platform C Horizontal velocity Ariane 5: A rapid change in attitude and high aerodynamic loads stemming from a high angle of attack create aerodynamic forces that cause the launcher to disintegrate at 39 seconds after command for main engine ignition (H0). Nozzles: Full nozzle deflections of solid boosters and main engine lead to angle of attack of more than 20 degrees. Self−Destruct System: Triggered (as designed) by boosters separating from main stage at altitude of 4 km and 1 km from launch pad. OBC (On−Board Computer) OBC Safety Constraint Violated: Commands from the OBC to the nozzles must not result in the launcher operating outside its safe envelope. Unsafe Behavior: Control command sent to booster nozzles and later to main engine nozzle to make a large correction for an attitude deviation that had not occurred. Process Model: Model of the current launch attitude is incorrect, i.e., it contains an attitude deviation that had not occurred. Results in incorrect commands being sent to nozzles. Feedback: Diagnostic information received from SRI Interface Model: Incomplete or incorrect (not enough information in accident report to determine which) − does not include the diag...
View Full Document

Ask a homework question - tutors are online