Falcon 9 Block 5

Block 5 was shaped by two outside customers: NASA's commercial crew certification and United States national security launch requirements. Building on Full Thrust, engine thrust rose by seven to eight per cent, the flight control system was reworked to hold a better angle of attack on descent — cutting the propellant held back for landing — and everything that made recovery expensive was redone.

The change list is long and unglamorous item by item: a reusable heat shield at the base of the rocket, cast and machined titanium grid fins, a black thermal coating on legs, raceway and interstage, requalified longer-life valves, retractable legs so a booster can be folded rather than dismantled, and an engine octaweb bolted together instead of welded. The helium pressure vessels were redesigned outright after the 2016 pad accident.

The first launch on 11 May 2018 carried the Bangabandhu-1 communications satellite, and that same booster flew again months later. The changeover finished on 29 June 2018, when the last Block 4 mission gave way to an all-Block 5 fleet. The stated target was ten flights per booster with nothing but inspections in between, and up to a hundred with periodic refurbishment; the first of those was reached in 2021.

Refinement never stopped: a relief valve in the grid fin hydraulics after a landing failure, self-levelling legs after a booster was damaged at sea, tweaks to throttle settings and separation timing, and mission extension kits that let the upper stage coast for hours before injecting a payload into a high-energy orbit.

With Block 5, reuse stopped being a demonstration and became the economic basis of access to orbit. Its reliability and flight rate have no precedent among orbital launchers, and it underpins crewed Dragon missions, the deployment of the Starlink constellation and most commercial traffic to low Earth orbit.