List of Super Heavy boosters
Since April 2023, Super Heavy has been launched times, with successes and failures. Starship, the vehicle Super Heavy composes when combined with the Starship spacecraft, has been developed with the intention of lowering launch costs using economies of scale. SpaceX aims to achieve this by reusing both rocket stages, increasing payload mass to orbit, increasing launch frequency, creating a mass-manufacturing pipeline and adapting it to a wide range of space missions. Starship is the latest project in SpaceX's reusable launch system development program and plan to colonize Mars.
There are currently three planned versions of Super Heavy: Block 1, Block 2, and Block 3. As of September 2025, Block 1 vehicles and Block 2 vehicles have flown. The Super Heavy booster is reusable, and is recovered via large arms on the tower capable of catching the descending vehicle. As of May 2025, booster has been refurbished and subsequently flown at least a second time, though boosters, Booster 12, 14, and 15, have been recovered after flight, with Booster 12 having damage to one of its chine sections, and Booster 14 being reused.
Development
Ground testing (BN1–B6)
BN1
BN1 was the first Super-Heavy Booster prototype, a pathfinder that was not intended for flight tests. Sections of the ~ tall test article were manufactured throughout autumn 2020. Section stacking began in December 2020. BN1 was fully stacked inside the High Bay on March 18, 2021, and was scrapped on March 30, 2021.B3
Booster 3 completed stacking in the High Bay on June 29, 2021, and moved to the test stand. A cryogenic proof test was completed on July 13, followed by a static fire test on July 19. BN3/Booster 3 was partially scrapped on August 15, while the liquid oxygen tank remained welded to the Test Stand until January 13, 2022.B4–B5
B4 was fully stacked on August 1, with all 29 engines installed on August 2, 2021. Grid fins were added to support atmospheric reentry testing. S20 was stacked on top of Booster 4 on August 6, 2021 for a fitting test, making it, for two years, the tallest rocket ever fully integrated. B4 completed its first cryogenic proof test on December 17, 2021, followed by a pneumatic proof test, another cryogenic proof test and a full-load cryogenic proof test. B4 and Ship 20 were then retired. On March 6, 2024, B4s grid fins were removed, it was moved to the Mega Bay on March 21 where it was scrapped the following day.Parts for B5 were observed as early as July 19, 2021. Stacking for B5 completed in November, although on December 8, B5 was retired alongside SN15 and SN16. It was later scrapped.
Block 1 launches (B7–B13)
B7–B8
B7 was placed on the orbital launch mount on March 31, 2022, and completed two cryogenic proof tests in April, resulting in the rupturing of the downcomer. After being repaired, it was returned to OLP-1, and completed two cryogenic tests. It was then moved to Mega Bay 1 for engine and grid fin installation. On July 11, after returning to OLP-1 for engine testing, B7 experienced a detonation underneath the engines during an attempted 33-engine spin prime test. It returned to OLP-1 on August 4 with only the 20 outer Raptor engines, and completed its first single-engine static fire test on August 9, followed by a second two days later. After receiving its thirteen inner engines, B7 conducted a series of spin prime and static fire tests throughout August and September, before again returning to the Mega Bay on September 21. After receiving additional upgrades it was lifted on the launch pad on October 8. Ship 24 was stacked on top B7 on October 12, and was removed after completing multiple cryogenic load tests. B7 then completed a spin prime test of multiple engines on November 12, a 14-engine static fire test on November 14, and finally an 11-engine static fire in an autogenous pressurization test on November 29. In January 2023, Booster 7 and Ship 24 conducted a wet dress rehearsal, before attempting a 33-engine static fire on February 9. On April 20, 2023, Booster 7 was launched on Integrated Flight Test 1, being destroyed before stage separation after a fire in the aft section severed connections between its engines and flight computers, resulting in a loss of attitude control and FTS activation.B8 was fully stacked on July 8, 2022. It was moved to the launch site on September 19, 2022, though it was not tested there. Booster 8 was scrapped in January 2023 in favor of Booster 9. Booster 8's hydraulic power units were used to replace Booster 7's, along with several other parts, including the engine shielding.
B9–B13
B9 finished stacking in late 2022, and featured upgrades, including electric thrust vector control gimbaling system of the raptor engines, replacing the previous hydraulic power units that were used up to Booster 8. It was moved to the OLS cryogenic station on December 15. Two cryogenic proof tests were conducted on December 21 and December 29, both of which were successful. After engine installation, Booster 9 was rolled to OLP-1 on July 20, conducting a cryogenic proof test on OLP-1, followed by a spin prime test on August 4. On August 6, Booster 9 fired 29 engines for 2.7 seconds, instead of the planned 33 engines for five seconds. It was then moved off of OLP-1 and rolled back to Mega Bay 1, where its vented interstage was added on August 16. B9 was moved back to OLP-1 on August 22 and underwent another spin prime test the next day. On August 25, Booster 9 underwent a static fire of all 33 engines, with two engines shutting off early. Ship 25 was lifted onto B9 for the first time on September 5, and was destacked several times throughout the rest of the month and mid October. On October 22, B9 underwent two partial cryogenic tests, while S25 was not tested, followed by a full wet dress rehearsal two days later. On November 18, Booster 9 and Ship 25 lifted off with all 33 engines lit at 7:02 am CST. Following the successful separation from S25, B9 was destroyed after several engine failures during the boost-back burn.B10 was fully stacked in March 2023. B10 was moved to Massey's test site for cryogenic testing on July 7, undergoing a cryogenic proof test on July 18. Additional cryogenic tests were performed in mid September. B10 was moved back to Mega Bay 1 on September 19 for engine and interstage installation. On December 18, B10 was moved to the orbital launch site, followed by a lift onto OLP-1 the next day. It completed a 33-engine static fire test on December 29. On January 2, 2024, B10 was moved back to the Production Site, and was transported to the Orbital Launch Site for a WDR. On February 9, B10 was lifted onto OLP-1, and on February 10, Ship 28 was lifted onto B10, with the combined vehicle aborting two wet dress rehearsal attempts. The wet dress rehearsal was completed on March 3. The vehicles were destacked for FTS arming on March 5, which occurred on March 8, followed by S28 being restacked on March 10. On March 14, B10 was launched with S28 on IFT-3, completing the ascent burn with zero engine failures. Six engines failed during the boostback burn. During its landing burn, only three engines started up with two failing shortly thereafter.
B11 was fully stacked in June 2023. On October 12, B11 was moved to Massey's test site, where it was cryo-tested on October 14 and October 18. On November 19, B11 was moved back to Mega Bay 1 for engine and interstage installation. B11 was moved to OLP-1 for static-fire testing on April 4, where it conducted a 33-engine static-fire on April 5. On April 7, it was removed from OLP-1, and rolled back to Mega Bay 1 for preflight modifications. On May 10, B11 was rolled out of Mega Bay 1, and rolled to the Orbital Launch Site. It was lifted onto OLP-1 on May 11. On May 15, Ship 29 was lifted onto B11, with the combined vehicle completing a partial cryogenic test on May 16, and a full wet dress rehearsal on May 20, A second wet dress rehearsal was completed on May 28. On May 29, S29 was destacked for final tile work and Flight Termination System Installation, with FTS installation occurring on May 30. S29 was stacked onto B11 for the final time on June 5. On June 6, B11 and S29 launched on IFT-4, with a single engine failure occurring shortly after liftoff. The boostback burn saw no engine failures, though a second engine failed during the landing burn. B11 was destroyed after tipping over, with several components being recovered in late September. On October 9, Vice President of Build and Flight Reliability of SpaceX, Bill Gerstenmaier, claimed that B11 landed within "half a centimeter" of the target.
B12 began assembly in June 2023. On December 28, 2023, B12 was moved to Massey's for cryogenic testing, where it conducted two cryogenic tests on January 10 and January 12. B12 was moved production site in mid-January for engine installation. B12 was moved to OLP-1 on July 9 for static fire testing, where it conducted a pressurization test on July 11, followed by a 33-engine spin prime on July 12 and a 33-engine static fire on July 15. B12 was rolled back to the production site on July 16, 2024. SpaceX claimed that B12 and S30 were ready to fly on August 8. On September 20, B12 was rolled to the launch site, with S30 being lifted onto B12 the next day. A partial wet dress rehearsal was conducted on September 23. A second partial wet dress rehearsal occurred on October 7, followed by S30 being destacked for FTS installation. FTS was installed on both vehicles on October 9, and S30 was stacked onto B12 for Flight 5 on October 11. B12 and S30 launched on October 13, with B12 successfully conducting the ascent, boostback, and landing burns with no engine failures, before being caught by the tower's chopsticks, and lowered onto OLP-1. Musk claimed that B12 suffered damage that could be "easily addressed", including warping of the outer engine nozzles. B12's FTS was removed on October 14, followed by being returned to Mega Bay 1 for post-flight inspections. On October 22, B12's vented interstage was recovered, followed by B12 retirement to the rocket garden on October 28.
B13 and subsequent vehicles have upgraded liquid oxygen vents, a new raceway design, and reinforced chines. B13's assembly was completed on February 3, 2024. It was rolled to Massey's test site for cryogenic testing on April 25. B13 completed its first cryo-test on April 26, and a second cryogenic test on April 29. On October 22, B13 was rolled to OLP-A, where a partial cryogenic test was performed two days later. Following this, B13 conducted a static fire, and was subsequently rolled to Mega Bay 1. It returned to the launch site for IFT-6 on November 14, where Ship 31 was lifted onto the booster. FTS was installed on November 15, followed by a partial wet dress rehearsal on November 17. On November 19, B13 launched with S31, completing the ascent, boostback, and landing burns. However, the "catch" attempt was called off due to an issue with the launch tower, and the booster was diverted to splashdown in the Gulf of Mexico. B13's aft section was recovered in late July, 2025.