Nine Merlin 1D engines ignite in a precise sequence, ramping to full thrust while hold-down clamps keep the rocket grounded. Onboard computers verify all engines are healthy before releasing — if anything looks off, the system automatically aborts.

The hold-down clamps release and Falcon 9 lifts off the pad. The nine Merlin engines produce 1.7 million pounds of thrust, pushing the 549-tonne rocket skyward at an increasing rate. The first few seconds are the most critical — the rocket must clear the launch tower cleanly.

Maximum dynamic pressure — the moment the rocket endures the greatest aerodynamic stress. The atmosphere is still thick enough to create enormous force against the vehicle traveling at supersonic speed. Falcon throttles down its engines slightly to keep structural loads within limits, then throttles back up once past this point.

Main Engine Cutoff. The first stage's job is done — it has burned through roughly 400 tonnes of RP-1 kerosene and liquid oxygen in under 3 minutes, accelerating the vehicle to about 6,000 km/h. The engines shut down in preparation for stage separation.

Pneumatic pushers fire to separate the first and second stages. This is a critical moment — the two halves must separate cleanly at supersonic speed in near-vacuum. The first stage begins its journey back to Earth while the second stage continues to orbit.

The single Merlin Vacuum engine on the second stage ignites. Optimized for the vacuum of space with a much larger exhaust nozzle, this engine will burn for about 6 minutes to push the payload to orbital velocity — roughly 28,000 km/h.

The two halves of the payload fairing — the protective nose cone — split apart and fall away. The fairing shielded the payload from aerodynamic forces and heating during ascent. Each half is 13 meters tall and worth about $3 million. SpaceX catches them with ships or recovers them from the ocean for reuse.

The first stage flips around using cold gas thrusters and fires three of its engines to slow down for atmospheric re-entry. This "boostback" and entry burn reduces velocity from ~6,000 km/h to ~2,000 km/h, protecting the engines and airframe from destructive heating as it slams back into the thickening atmosphere.

The final deceleration burn. A single Merlin engine fires at nearly full thrust to bring the 25-tonne first stage from hundreds of km/h to a gentle touchdown. The burn lasts only ~20 seconds — there's no hovering. The engine's thrust exceeds the booster's weight, so the timing must be perfect: too early and it runs out of fuel, too late and it hits too hard.

The first stage touches down on SpaceX's drone ship at sea or on the landing pad at the launch site. Four deployable landing legs absorb the impact. This booster will be inspected, refurbished, and can fly again — some boosters have flown over 20 times. Each successful landing saves SpaceX roughly $30 million.

Second Engine Cutoff. The Merlin Vacuum engine shuts down after achieving the precise orbital velocity and altitude. The payload is now in its target orbit or transfer trajectory. For some missions, the second stage will coast and reignite later for a more precise orbit insertion.

The payload separates from the second stage and is released into its target orbit. Springs or actuators push the satellite away cleanly. The payload will then deploy its own solar panels and antennas and begin its commissioning phase. The second stage will either deorbit itself or remain in a disposal orbit.