Falcon 9 Block 5 is a two-stage-to-orbitmedium lift launch vehicle designed and manufactured domestically in the United States by SpaceX. It is the fifth version of Falcon 9 Full Thrust, powered by SpaceX Merlin engines burning liquid oxygen and rocket-grade kerosene propellants. In 2017, Falcon 9 Block 5 succeeded the transitional Block 4 version. The main changes from Block 3 to Block 5 are higher thrust engines and improvements to the landing legs. Numerous other small changes helped streamline recovery and re-usability of first-stage boosters, increase production rate, and optimize re-usability. Each Block 5 booster is designed to fly ten times with only minor attention, and up to 100 times with refurbishment. The maiden flight launched the satellite Bangabandhu-1 on May 11, 2018. The CRS-15 mission on June 29, 2018 was the last Block 4 version of Falcon 9 to be launched. This was the transition to an all Block 5 fleet.
Overview
The Block 5 design changes are principally driven by upgrades needed for NASA's Commercial Crew program and National Security Space Launch requirements. They include performance upgrades, manufacturing improvements, and "probably 100 or so changes" to increase the margin for demanding customers. In April 2017, SpaceX CEO Elon Musk said that Block 5 will feature 7–8% more thrust by uprating the engines. Block 5 includes an improved flight control system for an optimized angle of attack on the descent, lowering landing fuel requirements. For reusability endurance:
expected to be able to be launched at least 10 times.
up to 100 uses with refurbishment.
a reusable heat shield protecting the engines and plumbing at the base of the rocket;
a thermal protection coating on the first stage to limit reentry heating damage, including a black thermal protection layer on the landing legs, raceway, and interstage;
Redesigned and requalified more robust and longer life valves.
a set of retractable landing legs for rapid recovery and shipping.
the Octaweb structure is bolted together instead of welded, reducing manufacturing time.
Human rating
NASA required seven flights without major design changes before the vehicle can be certified for human spaceflight for carrying NASA astronauts. The initial Block 5 boosters did not have the redesigned composite overwrapped pressure vessel tanks. The first booster with COPV2 tanks was booster B1047 on the Es'hail 2 mission on November 15, 2018, and the second booster using the COPV2 tanks was CRS-16/B1050, which had its first launch on December 5, 2018. The Block 5 design launched astronauts for the first time on May 30, 2020, on a NASA-contracted flight labelled Crew Dragon Demo-2.
