T3-02 Main Engine Start

1. Zero-G Propellant Ullage & Main Engine Ignition

In microgravity, liquid bipropellant floats freely inside the main propellant tanks, uncovering the sump feedlines ([PROP_ULLAGE] UNSETTLED). Attempting to ignite the main orbital engine while propellant is unsettled draws gas bubbles into the turbopump, triggering cavitation and an automatic engine shutdown.

2. Ullage Settling & Orbital Burn Sequence

To execute a clean main engine burn:

• Stabilize Attitude: Null initial angular rates below 0.50 deg/s so the thrust vector remains aligned.
• Perform Ullage Burn: Fire forward-translating RCS thrusters to accelerate the hull forward and settle liquid propellant over the tank sumps until [PROP_ULLAGE] STATUS: SETTLED is reported.
• Ignite Main Engine: Command main engine thrust while propellant is settled to accumulate at least 15.0 m/s of forward delta-V, then cut off the engine and hold transverse rates below 0.50 deg/s.

3. Prompt Your Autonomous Agent

Prompt Antigravity to implement the ullage and main engine ignition sequence:

Read /api/specs/hardware/main_engine and /api/specs/hardware/rcs.
Update our flight computer to complete mission T3-02 (Main Engine Start & Burn):
1. Stabilize transverse attitude rates below 0.50 deg/s.
2. Fire forward RCS thrusters to settle propellant ([PROP_ULLAGE] SETTLED).
3. Ignite the main engine to achieve at least 15.0 m/s delta-V while keeping attitude stable.