Booster 8 (B8)

Booster 8 (B8) was a Super Heavy booster prototype. It was the second booster, after B7, that had a full 33 raptor engine layout. First parts have been spotted in January 2022. After a successful 7 engine static fire with booster 7 on 19 September 2022, Elon Musk announced that booster 8 would soon roll out to the pad for testing, while B7 will roll back to the production site for upgrades. The booster rolled out to the launch site on the same day, grid fins and engines have not been installed. However, SpaceX decided to delay the start of B8's testing campaign in order to focus on more urgent OLM upgrades to support a 33 engine static fire on B7. Later it was decided to skip the booster and started testing booster 9. B8 was scrapped in early 2023.

## Timeline

* 24 Oct 2021: Booster methane transfer tube (downcomer) delivered (two parts) [add Dec: not first one; first one see early Oct, likely for B7/B8]
* 21 Jan 2022: B7/B8 aft dome section sleeved (4-ring segement, 2 rings stiffeners; smaller rings [???]; 33 engines) and lifted from sleeving stand; 3-ring booster fwd dome sleeve with 2-rings stiffeners infront of it
* 21 Jan 2022: Booster fwd dome attached to crane, lifted onto sleeving stand [likely B7/B8], sleeved with the 3-ring booster fwd dome sleeve
* 22 Jan 2022: [B7/B8?] fwd section lifted off sleeving stand, moved into tent 1
* 22 Jan 2022: [B7/B8?] section lifted into high bay for stacking (4-ring with lead-ins)
* 26 Jan 2022: Booster [B8] fwd dome sleeve rolled out of tent 1 again after being rolled back in; attached to crane, lifted and flipped; attached to another crane, sleeved
* 29 Jan 2022: Common dome section flipped at 10:57am
* 31 Jan 2022: B8? fwd dome section/segment spotted in tent
* 03 Feb 2022: LCH4 tank sump [connecting the main LCH4 tank with the transfer tube/downcomer] delivered to production site
* 14 Feb 2022: LCH4 sump next to transfer tube
* 15 Feb 2022: Aft #2 and aft #3 sections spotted (4-ring)
* 17 Feb 2022: Ship section (4-ring) test fit with a booster fwd section, possibly B8 and S24; then removed again; another fit check followed [**stage separation** / clamp system tests]
* 17 Feb 2022: Aft #2 section (4-ring) spotted outside high bay; being cleaned
* 18 Feb 2022: B8 **stacking began** in high bay; 4-ring section lifted by bridge crane; aft tank #2 (4-ring section) moved into high bay, lifted and stacked; B8 common dome section (4-ring with ullage vents below stringers) outside high bay
* 19 Feb 2022: Common dome section lifted in high bay and stacked
* 20 Feb 2022: Common dome section moved out of high bay (destacked, likely to be scrapped [see: [187]])
* 27 Feb 2022: Common dome seen
* 02 Mar 2022: Booster aft dome sleeve (4-ring) in front of tents, aft dome on sleeving stand, workers wrap up extending pipes for engines with plastic bags; aft dome sleeved [B8/B9?]
* 02 Mar 2022: Booster fwd section near high bay [B8?]
* 06 Mar 2022: Fwd tank #2 (3-ring) spotted ("goes directly underneath the forward dome section")
* 06 Mar 2022: B8? fwd dome section spotted
* 08 Mar 2022: B8 common dome section (4-ring) at scrap yard
* 11 Mar 2022: Fwd section moved into high bay to start with stacking
* 12 Mar 2022: B8 stacking [re]started: fwd dome section lifted and stacked on another 3-ring section (LCH4 tank now 6/13 rings)
* 13 Mar 2022: Booster aft section (4-ring) flipped; **header tank part visible** (with three-engine pipe outlets!) [B8/B9?]
* 17 Mar 2022: Booster header tank outside tents [B8/B9?]
* 18 Mar 2022: Booster header tank still outside tents (for LOX) [B8/B9?]
* 19 Mar 2022: Booster header tank lifted [B8/B9?] and moved into tent 2?
* 20 Mar 2022: New booster comn dome section moved out of tent 1 (4-ring, sleeved), ullage vents preinstalled [B8/B9?]; attached to flipping jig, flipped
* 25 Mar 2022: Fwd tank section #4 moved into high bay (4-ring)
* 30 Mar 2022: CH4 tank stacking continued in high bay; stacked onto fwd section #4, now 13/13 rings tall
* 01 Apr 2022: Aft tank #2 section (4-ring, no lead-ins) attached to crane and moved into high bay
* 02 Apr 2022: Common dome section moved in front of high bay, LOX tank vents seen; lifted onto aft #2 section (LOX tank now 8/24 rings tall)
* 03 Apr 2022: Work in high bay continued, weld cleaned while the tank got rotated
* 04 Apr 2022: **S24 aft section moved to high bay, and stacked onto B8 fwd section**
* 05 Apr 2022: S24 aft section removed from B8 aft section after fit check of **stage separation** system
* 06 Apr 2022: LOX tank has been moved into mid bay recently [RGV aerial]
* 14 Apr 2022: Methane tank section rolled out and moved into mid bay again; B8 LOX section moved out of mid bay
* 14 Apr 2022: Common dome and aft #2 section outside high bay (8 rings tall stack); moved into high bay later
* 15 Apr 2022: LOX tank stacked: cmn dome and aft #2 sections stacked onto aft #3 section (now 12/24 rings tall)
* 17 Apr 2022: Aft #4 tank section (4-ring, part of LOX tank) prepared for lifting in front of high bay; lifted and placed on a stand; LOX tank moved within high bay, lifted by bridge crane and stacked onto aft #4 section (LOX tank now 16 rings tall)
* 18 Apr 2022: LOX tank moved within high bay by bridge crane; then moved out of high bay, likely to make place for B7
* 22 Apr 2022: B8? thrust section flipped
* 25 Apr 2022: LOX tank worked outside
* 26 Apr 2022: Fwd section seen in mid bay
* 08 May 2022: LOX tank section still waiting outside bay area
* 09 May 2022: Aft tank worked on the outside
* 10 May 2022: LOX tank worked on
* 15 May 2022: LOX section (16 rings tall) moved into high bay 1, attached to bridge crane to resume stacking operations; stacked onto another 4-ring section (LOX tank now 20 out of 24 rings tall)
* 17 May 2022: S24 and B8 worked on in high bay 1
* 18 May 2022: High bay 1 bridge crane connected to B8 LOX tank section
* 19 May 2022: Methane transfer tube lifted into LOX tank
* 20 May 2022: Still connected to bridge crane in high bay 1
* 23 May 2022: LOX tank work continued in high bay 1
* 25 May 2022: Worked on in high bay 1, while still being connected to high bay bridge crane
* 28 May 2022: Booster fwd tank #2 spotted [B8/B9, barely readable]
* 31 May 2022: Engine section moved from tent to high bay (header tank visible)
* 01 June 2022: LOX tank stacked on engine section in high bay 1; after being stacked and destacked twice
* 03 June 2022: LOX tank section rotated in high bay
* 03 June 2022: B8 transport stand moved to the build site
* 03 June 2022: LOX tank moved inside high bay 1; placed on new booster transport stand [vid 04]
* 05 June 2022: LOX tank moved from high bay 1 to high bay 2
* 11 June 2022: Methane tank in high bay
* 27 June 2022: Methane section spotted in mid bay
* 06 July 2022: Fwd section (13-rings tall CH4 section) moved into mega bay/high bay 2
* 07 July 2022: Bridge crane attached to CH4 tank in mega bay
* 07 July 2022: B8 stacked in high bay 2/mega bay; CH4 tank lifted (**final stacking)**
* 08 July 2022: B8 has been stacked (hidden in mega bay/high bay 2); now **fully stacked**
* 13 July 2022: Fwd dome section spotted; camera attached at the top
* 30 July 2022: Moved within mega bay, likely making way for B9 stacking
* 01 Aug 2022: Worked on in mega bay, B7 isn't visible in mega bay
* 03 Aug 2022: B7 and B8 spotted in mega bay [vid 04]
* 05 Aug 2022: SPMT moved into mega bay to move B8 away from the entrance
* 10 Aug 2022: Seen in mega bay
* 17 Aug 2022: B7 and B8 (hidden) in mega bay, worked on
* 23 Aug 2022: Spotted in mega bay
* 25 Aug 2022: Worked on in mega bay
* 31 Aug 2022: Smaller chines added at 9:49 in mega bay
* 06 Sep 2022: Worked on in mega bay
* 07 Sep 2022: Work continued in mega bay
* 13 Sep 2022: B8 with chines installed in mega bay
* 19 Sep 2022: **B8 rolled out to the launch site** (grid fins and engines not yet installed) [vid 20]
* 29 Sep 2022: Fwd section still without grid fins [vid 30]

## Testing Campaign

### 19 September 2022 - Roll out

Timeline according to LabPadre discord:

* 14:46 B8 moved inside mega bay
* 18:00 B8 left mega bay
* 19:03 Entered Hwy 4
* 20:12 Arrived at launch site

### 31 Ocotober 2022 - Roll back

Timeline according to LabPadre discord:

* 06:53 Started to move
* 07:13 Entered Hwy 4
* 08:53 Arrived at build site, continued towards Sanchez Site
* 10:06 Arrived at Rocket Garden

## References

1. ↑ https://twitter.com/elonmusk/status/1571935414448963586