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Falcon 9 Block 5

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Falcon 9 Block 5
The Block 5 variant of the Falcon 9 launching Crew Dragon during the Demo-2 mission from Kennedy Space Center on May 30, 2020. The rocket's distinguishing black thermal-protection coating on the interstage is discernible.
FunctionMedium-lift launch vehicle
Country of originUnited States
Height69.8 m (229 ft) with payload fairing[1]
Diameter3.7 m (12 ft)[2]
Mass549,000 kg (1,210,000 lb)[2]
Payload to LEO (28.5°)
  • 22,800 kg (50,300 lb) [expended][3]
  • 17,500 kg (38,600 lb) [reuse][4]
Payload to GTO (27°)
  • 8,300 kg (18,300 lb) [expended][3]
  • 5,500 kg (12,100 lb) [reuse][3]
Payload to TMI
Mass4,000 kg (8,800 lb)[3]
Associated rockets
FamilyFalcon 9
Based onFalcon 9 Full Thrust
Launch history
Launch sites
Total launches298
Landings304 (including use as side booster)
First flight11 May 2018 (Bangabandhu-1)
Type of passengers/cargo
First stage
Powered by9 × Merlin 1D+
Maximum thrust7.6 MN (1,700,000 lbf)[5][6]
PropellantLOX / RP-1[7]
Second stage (large nozzle[b])
Powered by1 × Merlin 1D Vacuum
Maximum thrust934 kN (210,000 lbf)[2]
PropellantLOX / RP-1
Second stage (short nozzle[b][9])
Powered by1 × Merlin 1D Vacuum
Maximum thrust840.6 kN (189,000 lbf)[2]
PropellantLOX / RP-1

Falcon 9 Block 5 is a partially reusable, human-rated, two-stage-to-orbit, medium-lift launch vehicle designed and manufactured in the United States by SpaceX. It is the fifth major version of the Falcon 9 family and the third version of the Falcon 9 Full Thrust.[10][11] It is powered by Merlin 1D engines burning rocket-grade kerosene (RP-1) and liquid oxygen (LOX).

The main changes from Block 3 (the original Falcon 9 Full Thust) to Block 5 are higher-thrust engines and improvements to the landing legs along with numerous other small changes to streamline recovery and re-use of first-stage boosters and increase production rate. Each Block 5 booster is designed to fly 10 times with only minor maintenance and up to 100 times with major refurbishment.[12]

In 2018, Block 5 succeeded the transitional Block 4 version. The maiden flight of the Block 5 launched the satellite Bangabandhu-1 on May 11, 2018. The CRS-15 mission on June 29, 2018 was the last Block 4 version to be launched, completing the transition to an all-Block 5 fleet.[13][14]


Bangladeshi satellite Bangabandhu-1 was the first payload launched by Falcon 9 Block 5.[15]

The Block 5 design changes are principally[16] 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.[17]

In April 2017, SpaceX CEO Elon Musk said that Block 5 will feature 7–8% more thrust by uprating the engines (from 176,000 pounds-force (780,000 N) to 190,000 pounds-force (850,000 N) per engine).[12] 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;[18][19] achieved in 2021[20]
  • up to 100 uses with refurbishment;[19][18][21]
  • a reusable heat shield protecting the engines and plumbing at the base of the rocket;
  • more temperature-resistant cast and machined titanium grid fins;[22]
  • 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;[19]
  • a set of retractable landing legs for rapid recovery and shipping.[23]
  • the Octaweb[24] structure is bolted together instead of welded, reducing manufacturing time.[25]


Since the debut of Block 5, SpaceX has continued to iterate on its design, manufacturing processes, and operational procedures.[26] Among other changes, the initial Block 5 boosters did not have the redesigned composite overwrapped pressure vessel (COPV2) tanks.[27] 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.[28] 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.[29]

A pressure relief valve was added to the grid fins’ hydraulic system following a stall that resulted in a landing failure in 2018.[30][31] Similarly, after a booster was damaged at sea in 2022, much of the fleet was upgraded with "self-leveling" landing legs. These legs help ensure the booster can be properly secured to the Octograbber, even in suboptimal sea states.[32]

To improve the rocket's performance, SpaceX has tweaked throttle settings and separation timings.[26][33]

Mission extension kits[edit]

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.[34] 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.[35][36]

Merlin 1D Vacuum short nozzle version[edit]

Transporter-7 mission launch debuted a new Merlin 1D Vacuum 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 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.[8][35] As of June 2023, the characteristics of the small nozzle second stage are unknown.

Human rating[edit]

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.[27][28]

The Block 5 design launched astronauts for the first time on May 30, 2020, on a NASA-contracted flight labelled Crew Dragon Demo-2.[37] 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.[38]

See also[edit]


  1. ^ Starlink Group 9–3 second stage engine disintegration
  2. ^ a b Transporter-7 mission launch debuted a new Merlin 1D Vacuum nozzle extension design aimed at increasing cadence and reducing costs. This new nozzle extension is shorter and, as a result, the engine has a lower specific impulse and therefore performance. Due to this, it will only fly on missions that don't need Falcon 9's full performance capability.[8]


  1. ^ "Falcon User's Guide" (PDF). January 14, 2019. Archived from the original (PDF) on December 2, 2020. Retrieved February 26, 2019.
  2. ^ a b c d "Falcon 9". SpaceX. November 16, 2012. Retrieved April 30, 2016.
  3. ^ a b c d "Capabilities & Services (2016)". SpaceX. November 28, 2012. Archived from the original on August 2, 2013. Retrieved May 3, 2016.
  4. ^ Elon Musk (February 26, 2024). "Due to continued design improvements, this Falcon 9 carried its highest ever payload of 17.5 tons of useful load to a useful orbit".
  5. ^ SpaceX (May 11, 2018). "Bangabandhu Satellite-1 Mission". Retrieved February 25, 2019 – via YouTube.
  6. ^ SpaceX. "FALCON 9". SpaceX. Archived from the original on July 15, 2013. Retrieved March 2, 2019.
  7. ^ @elonmusk (December 17, 2015). "-340 F in this case. Deep cryo increases density and amplifies rocket performance. First time anyone has gone this low for O2. [RP-1 chilled] from 70F to 20 F" (Tweet). Retrieved December 19, 2015 – via Twitter.
  8. ^ a b "Transporter 7". Retrieved March 17, 2023.
  9. ^ Sesnic, Trevor (July 22, 2023). "EchoStar 24 | Falcon Heavy". Everyday Astronaut. Retrieved July 29, 2023.
  10. ^ "Falcon 9 & Falcon Heavy". Archived from the original on July 21, 2020. Retrieved February 3, 2021. The v1.2 design was constantly improved upon over time, leading to different sub-versions or "Blocks". The initial design, flying on the maiden flight was thus referred to as Block 1. The final design which has largely stayed static since 2018 is the Block 5 variant.
  11. ^ "Acme Engineering". Retrieved February 3, 2021.
  12. ^ a b Clark, Stephen (April 4, 2017). "Musk previews busy year ahead for SpaceX". Spaceflight Now. Retrieved April 7, 2018.
  13. ^ Ralph, Eric (June 5, 2018). "SpaceX will transition all launches to Falcon 9 Block 5 rockets after next mission". TESLARATI.com. Retrieved February 26, 2019.
  14. ^ Shanklin, Emily (June 29, 2018). "Dragon Resupply Mission (CRS-15)". SpaceX. Archived from the original on May 24, 2019. Retrieved February 26, 2019.
  15. ^ "SpaceX launch of first "block 5" Falcon 9 rocket scrubbed to Friday". CBS News. May 10, 2018. Retrieved July 1, 2021.
  16. ^ "Falcon-9 v1.2 (Block 5) (Falcon-9FT (Block 5))". Gunter's Space Page. Retrieved June 27, 2022.
  17. ^ NASA (February 17, 2017). "NASA Holds Pre-launch Briefing at Historic Pad 39A at Kennedy Space Center". Youtube. Public Domain This article incorporates text from this source, which is in the public domain.
  18. ^ a b SpaceX Test-Fires New Falcon 9 Block 5 Rocket Ahead of Maiden Flight (Updated). Robin Seemangal, Popular Mechanics. May 4, 2018.
  19. ^ a b c SpaceX is about to land a whole lot more rockets. Loren Grush, The Verge. July 22, 2018.
  20. ^ "SpaceX flies historic 10th mission of a Falcon 9 as Starlink constellation expands". May 8, 2021. Retrieved July 1, 2021.
  21. ^ Elon Musk on Twitter: I don't want be cavalier, but there isn't an obvious limit. 100+ flights are possible. Some parts will need to be replaced or upgraded.
  22. ^ Musk, Elon (June 24, 2017). "Flying with larger & significantly upgraded hypersonic grid fins. Single piece cast & cut titanium. Can take reentry heat with no shielding". @elonmusk. Retrieved March 16, 2018.
  23. ^ "SpaceX Test-Fires New Falcon 9 Block 5 Rocket Ahead of Maiden Flight (Updated)". Popular Mechanics. May 4, 2018.
  24. ^ "Octaweb Structure". www.thespacetechie.com. July 10, 2021.
  25. ^ "I am Andy Lambert, SpaceX's VP of Production. Ask me anything about production & manufacturing, and what it's like to be a part of our team!". reddit.com. April 24, 2018.
  26. ^ a b "SpaceX Building Airline-Type Flight Ops For Launch | Aviation Week Network". aviationweek.com. Retrieved January 15, 2023.
  27. ^ a b Clark, Stephen. "New helium tank for SpaceX crew launches still waiting to fly – Spaceflight Now". Retrieved December 6, 2018.
  28. ^ a b "SpaceX landing mishap won't affect upcoming launches". SpaceNews.com. December 5, 2018. Retrieved December 6, 2018.
  29. ^ Starbase Tour with Elon Musk [PART 2 // Summer 2021], August 7, 2021, retrieved January 15, 2023
  30. ^ Elon Musk & NASA/SpaceX DM1 - Post Launch Press Conference. Event occurs at 12:02. Retrieved April 13, 2024 – via www.youtube.com.
  31. ^ Graham, William (December 5, 2018). "Falcon 9 successfully lofts CRS-16 Dragon enroute to ISS - Booster spins out but soft lands in water". NASASpaceFlight.com. Retrieved April 13, 2024.
  32. ^ Dontchev, Kiko [@TurkeyBeaver] (December 26, 2023). "...Tippy boosters occur when you get a certain set of landing conditions that lead to the legs having uneven loading... In this state, securing with the OG is super challenging and often only partial successful. We came up with self leveling legs that immediately equalize leg loads on landing after experiencing a severe tippy booster two years ago on Christmas (first flight of 1069). The fleet is mostly outfitted, but 1058, given its age, was not..." (Tweet) – via Twitter.
  33. ^ Clark, Stephen. "SpaceX launches heaviest payload on Falcon 9 rocket – Spaceflight Now". Retrieved January 27, 2023.
  34. ^ Ralph, Eric (October 11, 2022). "SpaceX's first Falcon Heavy launch in three years eyes late-October liftoff". TESLARATI. Retrieved October 11, 2022.
  35. ^ a b Sesnic, Trevor (July 22, 2023). "EchoStar 24 | Falcon Heavy". Everyday Astronaut. Retrieved July 29, 2023.
  36. ^ "Falcon rockets use three configurations of their upper stage. How are they different?". July 31, 2023.
  37. ^ "NASA, Partners Update Commercial Crew Launch Dates – Commercial Crew Program". blogs.nasa.gov. February 6, 2019. Retrieved February 26, 2019. Public Domain This article incorporates text from this source, which is in the public domain.
  38. ^ "SpaceX Speeding Astronauts to Space Station in Landmark Trip". Bloomberg News. May 30, 2020.

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