B5

B5
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Booster 5 (B5) was the second orbital capable Super Heavy booster prototype after Booster 4. It has been fully assembled in the high bay. It then was rolled to the Sanchez Site (PPS), where booster 5 joined SN15 and SN16 in the rocket garden. In summer 2022, booster 5 finally rolled into the newly constructed mega bay (high bay 2) where it got cut in half and scrapped.

## History

The first parts of booster 5 were spotted at the end of July and the beginning of August. Major assembly work on the LOX tank section has been done during September and the CH4 tank followed in early October.

On 24 September 2021, a tank with smaller diameter was spotted in high bay. It is believed that this could be the "header tank" for the booster which contains fuel for the landing. Such a tank would be necessary, similarly to the ship, because it would be much harder to extract fuel from a nearly empty main tank in comparison to a full "landing"-tank. The community seemed to be unclear whether this tank was placed in the middle (around the methane transfer tube) or on the side of the booster.

With previous prototypes, SpaceX used to stack the segments first and install the other components such as avionics, plumbing, wiring, cables and grid fins only in a second step. Contrarily, on booster 5, work on installing those components began as they were still stacking the segments (Mid October, November).

On 19 November 2021, the CH4 tank section has been stacked onto the LOX tank in the high bay, completing the stacking process. On 08 December 2021, booster 5 was rolled from the high bay to the display stand at PPS/Sanchez site next to SN15 and SN16.

## Timeline

* 20 July 2021: B5 "aft dome" sleeve (unfinished) spodded
* 26 July 2021: B4/B5? downcomer pipe spotted
* 26 July 2021: Possible B5? thrust dome outside tents
* 07 Aug 2021: Lower bulkhead for Superheavy booster spotted [B5?]
* 10 Aug 2021: B5 comm dome sleeve (4-ring stack) and fwd tank #2 (3-ring stack with lead-ins) spotted
* 17 Aug 2021: Aft dome sleeve (3-ring) spotted
* 21 Aug 2021: B5? fwd tank #2 booster section (3-ring with lead -ins) spotted
* 22 Aug 2021: Aft dome booster section spotted (3-ring)
* 25 Aug 2021: Unknown 4-ring section lifted into mid bay at 11:05 pm [GSE8?, S21?, B5?]
* 27 Aug 2021: GSE7 in mid bay; unknown 6-ring section right to it [GSE8?, S21?, B5?]
* 01 Sept 2021: B5 [?] common dome sleeved (4-ring)
* 02 Sept 2021: B5? aft dome spotted
* 05 Sept 2021: B5? dome section (4-ring) prepared for flipping
* 06 Sept 2021: Booster [B5?] aft dome ready for sleeving on the stand
* 06 Sept 2021: Aft dome barrel section ready for sleeving; flipped at 2:47 pm
* 07 Sept 2021: Aft dome sleeved early in the morning
* 10 Sept 2021: Fwd dome sleeve flipped at 9:16 am
* 10 Sept 2021: Fwd dome placed on sleeving stand [B5 fwd dome sleeve right behind the yellow crane in the video]
* 10 Sept 2021: Cmn dome moved into high bay
* 11 Sept 2021: Fwd dome sleeved with 3-ring (enforced) section
* 12 Sept 2021: Thrust dome sleeve flipped at 2:01am
* 12 Sept 2021: Fwd section now sleeved, put on a stand
* 12 Sept 2021: Cmn dome section and aft #2 section stacked in high bay by bridge crane; now 8 rings tall
* 13 Sept 2021: Barrel sections at production site: some are likely for B5
* 13 Sept 2021: Cmn dome section and aft #2 section stacked in high bay by bridge crane; now likely 8 rings tall [actually already yesterday]
* 14 Sept 2021: Stacking in high bay seems to have continued (another LOX tank section?)
* 14 Sept 2021: Fwd tank section #2 (3-ring stack) infront of tents
* 14 Sept 2021: Fwd dome sleeve moved (with dome)
* 15 Sept 2021: Stacking in high bay continued; now apparently 12 rings tall
* 16 Sept 2021: Stacking in high bay; now at least 12 rings [?] tall LOX section
* 17 Sept 2021: Fwd dome moved into production tent; stacking of LOX section continued, now 16 rings tall
* 18 Sept 2021: Stacking continued; 16 rings tall and a new 4-ring segment prepared in high bay
* 19 Sept 2021: Stacking continued, now 20 rings tall LOX section
* 21 Sept 2021: B4/B5/B6?? fwd dome sleeve spotted (3-ring with strengthening/enforcement)
* 21 Sept 2021: B4/B5/B6?? aft tank #3 segment spotted (4-ring)
* 24 Sept 2021: Blue booster COPV cover [B4/B5?] spotted
* 24 Sept 2021: Large pipe spotted infront of high bay [B5 downcomer?]
* 24 Sept 2021: A small diameter tank spotted in high bay next to B5
* 24 Sept 2021: Lifted in high bay to facilitate further stacking operations [vid 25]
* 25 Sept 2021: B5? fwd section inside production tent spotted, with stringers (vertical supports)
* 26 Sept 2021: Fwd #4 section (4-ring and lead-ins) spotted
* 29 Sept 2021: B5? fwd section (3-rings with stiffeners) outside high bay
* 29 Sept 2021: Cmn dome section worked on in high bay; LOX section is hooked to bridge crane
* 29 Sept 2021: Two grid fins spotted
* 30 Sept 2021: Fwd dome section moved into high bay
* 30 Sept 2021: Grid fins ready for installation
* 02 Oct 2021: Booster thrust puck delivered [B5?, B6?]
* 04 Oct 2021: B5? fwd section prepared for stacking, attached to crane
* 04 Oct 2021: Booster 3-ring fwd section [thought to be B5?] stacked on the booster sleeve with ship thrust puck for unknown reason
* 05 Oct 2021: Fwd #4 section spotted (4-ring with lead-ins)
* 05 Oct 2021: B5 grid fins shown
* 05 Oct 2021: Booster fwd section spotted in a tent [B5/B6?]
* 05 Oct 2021: Booster [B5/B6?] thrust puck with 13 engine mounts delivered for booster with new 33 engine design (3, 10, 20 vs 1, 8, 20) [add: likely B7?]
* 06 Oct 2021: New booster thrust puck for 13 engines [B5/B6?] lifted from truck [add: likely B7?]
* 06 Oct 2021: B5? grid fin moved into tent 1
* 06 Oct 2021: Fwd section stacked in high bay (currently 6 rings?)
* 06 Oct 2021: Fwd CH4 tank section now likely 9 rings tall; more sections ready
* 09 Oct 2021: Stacking continued; 3 out of 3 sections stacked
* 12 Oct 2021: Stacking continued; CH4 tank now 13 rings tall and thus completely stacked
* 12 Oct 2021: First grid fin installed
* 13 Oct 2021: First grid fin installed during night; a second one was installed later Assembly of catch/stack arms "chopsticks" and carriage continued
* 17 Oct 2021: Construction in high bay continued
* 21 Oct 2021: Aft tank #5 (LOX section, 4-rings, no lead-ins) moved
* 22 Oct 2021: Booster aft tank#5 and #3 spotted [B6?, signs look like B4 and B5]
* 27 Oct 2021: Work in high bay continued
* 08 Nov 2021: Work in high bay continued
* 09 Nov 2021: Thrust section lifted in high bay
* 09 Nov 2021: LOX section stacked on thrust/aft section
* 10 Nov 2021: Work in high bay continued
* 15 Nov 2021: Scaffolding installed at the top of LOX section in prepartion of stacking; transport stand moved into high bay
* 18 Nov 2021: Methane section moved in high bay
* 19 Nov 2021: LOX tank lifted onto a transport stand
* 19 Nov 2021: Methane tank section load spreader attached lifted by bridge crane and **stacked onto LOX section** (final stacking)
* 20 Nov 2021: Welding of the two sections
* 21 Nov 2021: Work continued
* 02 Dec 2021: Unhooked from gantry crane in high bay
* 03 Dec 2021: Rolled out of highbay for a few minutes before rolling back in again
* 04 Dec 2021: B5 hooked to bridge crane again; has all the aft section hardware installed already, but no covers yet installed
* **08 Dec 2021**: B5 unhooked from bridge crane; **B5 moved** **out of high bay to the booster display stand recently constructed** (located at PPS next to SN15 and SN16; engine production is confirmed to be slower than booster productin, so either B5 is being retired or on a waiting position)
* 15 Dec 2021: B6 test tank moved to PPS, moved next to SN15, SN16, B5
* 17 Dec 2021: Rocket garden at PPS: B5, BN2.1, B2.1, SN15, B6, SN16
* 03 Feb 2022: B5 at PPS: hydraulic power unit removed