Falcon 9 Block 5

Falcon 9 Block 5 is a partially reusable two-stage-to-orbit medium-lift launch vehicle designed and manufactured in the United States by SpaceX. It is the fifth version of Falcon 9 Full Thrust, powered by SpaceX Merlin engines burning rocket-grade kerosene (RP-1) and liquid oxygen (LOX).
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 10 times with only minor attention and up to 100 times with refurbishment.
In 2018, Falcon 9 Block 5 succeeded the transitional Block 4 version. 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 (from to per engine). 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; achieved in 2021
up to 100 uses with refurbishment;
a reusable heat shield protecting the engines and plumbing at the base of the rocket;
more temperature-resistant cast and machined titanium grid fins;
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;
redesigned composite overwrapped pressure vessels (COPV 2.0) for helium, to avoid oxygen freezing inside the structure of the tanks that lead to rupture.
For rapid reusability:
reduced refurbishment between flights;
a set of retractable landing legs for rapid recovery and shipping.
the Octaweb structure is bolted together instead of welded, reducing manufacturing time.
Improvements
Since the debut of Block 5, SpaceX has continued to iterate on its design, manufacturing processes, and operational procedures. Among other changes, the initial Block 5 boosters did not have the redesigned composite overwrapped pressure vessel (COPV2) 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. To improve the rocket's performance, SpaceX has tweaked throttle settings and separation timings. Later Block 5 boosters are also easier to prepare for flight, so SpaceX "prefer to retire" older cores by assigning them to expendable missions when possible.
Mission extension kits
SpaceX CRS-18 featured a Falcon mission-extension kit to the standard second stage, which equipped the second stage with a dark-painted band (for thermal control), extra COPVs for pressurization control, and additional TEA-TEB ignition fluid. The upgrades afforded the second stage with the endurance needed to inject the payloads directly into geosynchronous or high energy orbit where the second stage needs hours after launch. Based on mission requirements, they are Medium Coast & Long Coast kits, i.e., the number of helium bottles for pressurization and added batteries for power and other hardware to make sure that the fuel and stages systems operate as long as needed.
Short MVac nozzle version
Transporter-7 mission launch debuted a new MVac nozzle extension design or variant aimed at increasing cadence and reducing costs. This new nozzle extension is shorter and, as a result, decreasing both performance and material usage; but with this nozzle, the MVac engine produces 10% less thrust in space. This nozzle is only used on lower-performance missions, as it decreases the amount of material needed by 75%. This means that SpaceX can launch over three times as many missions with the same amount of rare Niobium metal as with the longer design. As of June 2023, the characteristics of the small nozzle second stage are unknown.
Human rating
The NASA certification processes of the 2010s specified seven flights of any launch vehicle without major design changes before the vehicle would be NASA-certified for human spaceflight, and allowed to fly NASA astronauts.
The Block 5 design launched astronauts for the first time on May 30, 2020, on a NASA-contracted flight labelled Crew Dragon Demo-2. This was the first crewed orbital spaceflight launched from the United States since the final Space Shuttle mission in 2011, and the first ever operated by a commercial provider.
See also
Falcon 9 Full Thrust, has 1st & 2nd stage specifications
Falcon Heavy, derivative launcher
List of Falcon 9 and Falcon Heavy launches
List of Falcon 9 Block 5 first-stage boosters
Saturn IB, Apollo crewed LEO launcher (1966-1975)
SpaceX Starship
Falcon 9
Notes
References
External links
Link to Falcon User's Guide, by SpaceX. Updated in January 2019 specifically for Block 5 upgrades.
SpaceX launch vehicles
Partially reusable space launch vehicles
Vehicles introduced in 2018
Falcon 9