LV2 Launch Sequence
| Up: | Software |
|---|---|
| Xref: | FlightComputerStateFlowSep2003,LaunchControl |
| LC | Launch Controller (a person) |
| LTC | Launch Tower Computer |
| FC | Flight Computer |
| launchcontrol | java program that sequences the launch - run by the LC |
ASSUMPTIONS
- Bullet points are basically sequential; one must happen before the other.
- Any deviation (warning, error, or missed step) after T-120 seconds will abort the countdown and return the FC to Preflight checking
SETUP
- The avionics system is bench tested.
- The "Ready for Flight" bit is set (non-debug mode).
- The avionics system is turned off and stowed in LV2.
- The rocket is brought to the pad; the umbilical cord connector is plugged in.
- LC turns on shore power via launchcontrol.
PRE-COUNT DOWN
- LC toggles the shore power relay using launchcontrol to turn on the avionics system.
- FC boots up and initializes system.
- FC sends message to launchcontrol that it's in Idle state.
- LC using launchcontrol sends message to FC to enter Preflight-check state (LC_START_PREFLIGHT_CHECK)
- FC starts and waits for CAN node initialization (longest wait = GPS) and then sends message to launchcontrol that it's in the Ready state.
LC verifies FC state using rocketview, ATV using VCR, and does a sanity check before continuing (lots of checklists here).
LC starts countdown using launchcontrol.
COUNT DOWN: T-120 SECONDS
- launchcontrol turns off the shore power (LTR_SHORE_POWER_OFF).
COUNT DOWN: T-110 SECONDS
- launchcontrol sends a message to FC to enter Armed state (LC_ARM_FC_FOR_COUNTDOWN)
- FC confirms the entire avionics system is armed.
COUNT DOWN: T-30 SECONDS
- launchcontrol turns on sirens and strobes (LTR_SIREN_ON,LTR_STROBE_ON)
COUNT DOWN: T-10 SECONDS
- LC MUST confirm launch via keypress or password or whatever before T-5 seconds
COUNT DOWN: T-5 SECONDS
- launchcontrol tells FC it's T-5 seconds (LC_T-5_SECONDS)
- FC acknowledges the T-5 message.
- FC sets and checks recovery timers.
- FC asserts rocketready and informs launchcontrol that rocketready is on.
COUNT DOWN: T-0 SECONDS
- launchcontrol turns on igniter relay.
ON LAUNCH DETECT
- FC detects launch and tells launchcontrol.
- launchcontrol turns off igniter relay, sirens, strobes and resets.
- launchcontrol stands by; nothing left to do
COUNT DOWN: T+15 SECONDS (NO LAUNCH DETECT)
- launchcontrol turns off igniter relay
- launchcontrol stands by.
ABORT
- launchcontrol turns off igniter relay.
- launchcontrol tells FC to abort (LC_ABORT_LAUNCH).
- On cofirmation of abort, launchcontrol turns off siren and strobe.
- FC goes back to Pre-flight check state.