S21

Ship 21 (S21) was a Starship prototype that had been partially built before being scrapped. By the end of December 2021, the nosecone had reached a mostly finished state, following months of meticulous work on the Thermal Protection System (TPS) tiles. However, the tank section was still missing its aft fins, and extensive repair work was required for the TPS tile coverage. At this point, the two parts had not yet been stacked together. Ship 21 appeared to be put on hold from late December 2021 onwards.

In February 2022, Ship 21's nosecone was reassigned to Ship 22 (S22). Subsequently, in April 2022, Ship 21 was scrapped.

It is likely that Ship 21 was constructed using 3.6mm stainless steel.

## History

The first part was likely spotted on 21 May 2021, but this part was then reused for GSE5. In June, new parts have been spotted. By the end of September 2021 most sections except the aft flaps have been spotted. Unlike with previous prototypes, it was thought that the improvements from S20 to S21 are bigger. After the landing of SN15, SpaceX aimed to do several orbital flights. It was believed that Ship 21 could go orbital with booster 5 however this never happended.

From October to December, the nosecone saw extensive three-month work on the TPS tiles. It can be assumed that the crew has been able to learn a lot about TPS tile attachment during this period. On 07 November 2021, the nosecone has been stacked onto its barrel section and the tank section has been completely stacked. In December 2021, the tank section of ship 21 saw a lot of movement at the production site between high bay and mid bay, the reason of this however is unknown.

In February 2022, its nosecone was reassigned to Ship 22 (S22) and in April 2022, the tank section was finally being scrapped.

## Timeline

* 21 May 2021: Marcus House: Combinations SN20-BN3, SN21-BN4, SN22-BN5, SN23-BN6, then major upgrades for SN24-BN7
* 21 May 2021: SN21 common dome spotted [Starship Gazer]
* 22 May 2021: SN21 common dome [not yet stacked] now for GSE5 (fwd dome)
* 14 June 2021: Starship SN21 or above thrust puck spotted
* 25 June 2021: New S21[?] thrust/aft dome sleeved (3-ring stack)
* 27 June 2021: S21 aft dome with vacuum raptor engine mounts spotted
* 03 July 2021: B4? fwd dome section and S21? aft section near each other after stacking test
* 03 July 2021: SN21/S21 thrust dome upgraded
* 04 July 2021: Booster fwd dome [B4?], Starship aft skirt, S21 aft dome infront of tents
* 06 July 2021: Single ring section stacked onto 2-ring section infront of tents [SN20/S21 aft section used on June 30??]
* 07 Aug 2021: S21 nosecone spotted in tent 3
* 12 Aug 2021: S21 legskirt spotted (2-ring); label still "SN"
* 12 Aug 2021: Aft dome spotted
* 13 Aug 2021: Aft dome moved into production tent
* 19 Aug 2021: Aft dome sleeve (3-ring) spotted
* 19 Aug 2021: Aft dome prepared for lifting; lifted on stand; sleeved with 3-ring aft stack
* 20 Aug 2021: S21 sleeved aft section lifted off from sleeving stand
* 22 Aug 2021: Fwd flap "flap py - studded" arrived at tent 4
* 24 Aug 2021: Nosecone barrel section (seen already yesterday, 4-ring) in tent 3 spotted
* 24 Aug 2021: New ship or tank section with lead-ins spotted in mid bay [GSE8 or S21??]
* 25 Aug 2021: Unknown 4-ring section lifted into mid bay at 11:05 pm [GSE8?, S21?, B5?]
* 26 Aug 2021: Aft section (3-ring sleeve with dome) on stand, not yet flipped
* 27 Aug 2021: Aft dome section (3-ring and dome) flipped infront of tents; inside of dome clearly visible
* 27 Aug 2021: Nosecone barrel section moved; a label on it indicates that it is made of **3.6mm steel** [!!!!]
* 27 Aug 2021: GSE7 in mid bay; unknown 6-ring section right to it [GSE8?, S21?, B5?]
* 14 Sep 2021: S21 (potentially?) cmn dome and a methane header tank spotted
* 14 Sep 2021: Cmn dome sleeve (4-ring section) spotted
* 14 Sep 2021: S21? cmn dome has been placed on sleeving stand
* 16 Sep 2021: Deliveries to production site; aerocovers for new Starship delivered [S21?]
* 17 Sep 2021: Methane transfer tube [S21?]delivered to production site (downcomer)
* 18 Sep 2021: Ship [S21?] aerocover delivered
* 21 Sep 2021: Nosecone receiving thermal blankets ahead of TPS tile installation
* 21 Sep 2021: Mid LOX section with lead-ins and a lot of TPS tiles installed spotted
* 21 Sep 2021: Fwd dome on sleeving stand, 4-ring barrel section connected to crane
* 23 Sep 2021: Fwd dome sleeved
* 23 Sep 2021: Fwd flaps spotted
* 23 Sep 2021: S21 4-ring barrel section with TPS blankets spotted
* 24 Sep 2021: Barrel sections with TPS tiles attachement in progress spotted
* 24 Sep 2021: Nosecone TPS installation continued in tent
* 26 Sep 2021: Aft section outside tents (5 rings and lead-ins; thrust and skirt sections)
* 26 Sep 2021: Nosecone TPS installation continued
* 26 Sep 2021: S21 cmn "comm" dome section (3-ring) spotted; previously slated for S22
* 27 Sep 2021: Barrel section with lead-ins [S21?] spotted in mid bay
* 28 Sep 2021: Nosecone TPS tiles installation continued
* 29 Sep 2021: Nosecone TPS tiles installation continued inside tent 3
* 30 Sep 2021: Nosecone and nosecone barrel section TPS tiles installation; first fwd flap installted to nosecone
* 01 Oct 2021: Ship [S21?] cmn dome with TPS tiles attachment points and CH4 header tank spotted
* 01 Oct 2021: Nosecone work continued, second aft flap installed
* 02 Oct 201: S21 4-ring section in mid bay waiting for stacking to begin
* 05 Oct 2021: Nosecone [S21?] work in tent 3 continued, TPS tiles being attached
* 07 Oct 2021: Nosecone work continued; progress on TPS installation marginal; as well as on barrel section
* 08 Oct 2021: Nosecone TPS heat shield tiles installation continued, red tape added to the top, some tape on the flap TPS tiles
* 09 Oct 2021: Barrel section with TPS tiles (some empty spots) (3-rings with lead-ins) hooked to crane in front of mid bay, possibly for S21?; another 4-ring section in front of mid bay
* 09 Oct 2021: Common dome moved into mid bay
* 11 Oct 2021: Nosecone TPS tiles installation has progressed
* 11 Oct 2021: S22 [sic! it's S21] in mid bay likely 6-7 rings tall
* 12 Oct 2021: Nosecone TPS work continued
* 12 Oct 2021: S21? nosecone barrel section (the one that has been standing there since a long time) TPS installation
* 12 Oct 2021: Tent 3: 4-ring barrel section with a lot of TPS tiles attached [vid 13 labelled S21 fwd section]
* 13 Oct 2021: Fwd section in tent 3 TPS tiles installed [also see yesterday]
* 14 Oct 2021: Nosecone and nc barrel section TPS installation continued
* 17 Oct 2021: Crane detached from S21 nosecone barrel section
* 19 Oct 2021: Nosecone and nc barrel section look nearly ready
* 21 Oct 2021: Fwd dome section work
* 23 Oct 2021: Nosecone and nc barrel section still missing some few tiles
* 23 Oct 2021: Fwd section **stacked** on common dome section in mid bay
* 24 Oct 2021: **Nosecone rolled out of tent 3**, at least 3 nosecone still inside
* 25 Oct 2021: Work in mid bay
* 26 Oct 2021: In mid bay at least 7-8 rings tall, work through hatch; mass simulator plate installed
* 26 Oct 2021: Nosecone TPS tiles work continued
* 27 Oct 2021: Work continued in mid bay
* 30 Oct 2021: Nosecone work continued
* 02 Nov 2021: Work in mid bay continued; work platform erected
* 05 Nov 2021: Engine section (5-rings, with lead-ins) moved to mid bay; lifted into mid bay
* 06 Nov 2021: Nosecone prepared for lifting, attached to crane
* **07 Nov 2021: In mid bay now 16 rings tall; stacking of tank section complete**
* **07 Nov 2021: Nosecone stacked on nosecone barrel section**; TPS tile rows on nosecone are labelled
* 08 Nov 2021: Nosecone welding work; nosecone still attached to crane
* 09 Nov 2021: Nosecone disconnected from crane; work continued
* 10 Nov 2021: Nosecone TPS tiles worked on
* 11 Nov 2021: Nosecone work continued
* 11 Nov 2021: In mid bay: preparation work for **aft fin** installation
* 12 Nov 2021: Nosecone TPS tiles worked on
* 13 Nov 2021: Nosecone work continued
* 14 Nov 2021: New black plate spotted on the hull, just left above the QD area
* 16 Nov 2021: Nosecone TPS tiles worked on
* 17 Nov 2021: Nosecone construction and TPS tiles work continued
* 17 Nov 2021: Work in mid bay continued
* 18 Nov 2021: Tank section worked on in mid bay
* 19 Nov 2021: Nosecone TPS tiles inspected
* 19 Nov 2021: Aerocovers staged for installation on S21; some tiles on it
* 19 Nov 2021: Nosecone green tape affixed; aft section prepared for aft fin installation
* 20 Nov 2021: Nosecone work continued, more tapes added
* 20 Nov 2021: New Starship segment [S22?] spotted next to S21 NSF
* 21 Nov 2021: Nosecone work on TPS tiles continue, more tapes added
* 22 Nov 2021: Tank section worked on in mid bay
* 23 Nov 2021: Nosecone TPS tiles work continued; many tapes around the flap
* 23 Nov 2021: Tank section work in mid bay continued
* 24 Nov 2021: Nosecone TPS tiles work continued; some tape removed
* 24 Nov 2021: Tank section in mid bay worked on
* 24 Nov 2021: S22 stacking has begun in mid bay; cmn dome section identified; next to S21
* 27 Nov 2021: Aft flap alignment jig fully installed on one side (other side not visible)
* 27 Nov 2021: Nosecone TPS tiles work continued, especially around flap; label spotted: "Attention do not move flap"
* 28 Nov 2021: Nosecone TPS tiles work continued
* 29 Nov 2021: Tank section work in mid bay continued
* 29 Nov 2021: Nosecone TPS tiles: new tapes added
* 30 Nov 2021: LOX header tank downcomer lifted into mid bay for installation in S21 (the\_denks)
* 30 Nov 2021: Nosecone TPS tiles work continued
* 01 Dec 2021: Nosecone TPS tiles, red tape added
* 02 Dec 2021: Nosecone TPS tiles work continued
* 03 Dec 2021: Nosecone TPS tiles work contineud
* 07 Dec 2021: Tank section work in mid bay through access hole
* 07 Dec 2021: Nosecone TPS tiles work continued
* 08 Dec 2021: Nosecone TPS tiles work continued
* 09 Dec 2021: Nosecone TPS tiles work continued
* 11 Dec 2021: Nosecone work continued, horizontal beam added between nc and nc barrel section
* 13 Dec 2021: Nosecone section moved towards high bay, tiles work continued
* 14 Dec 2021: Nosecone work continued infront of high bay, some tape has been removed
* 17 Dec 2021: Rolled out of mid bay; tiles not completely added, some broken or missing; aft flap mounting rig not yet installed; work platfrm on top has been removed some time ago
* 18 Dec 2021: Moved into high bay at around 7pm
* 19 Dec 2021: Tank section moved into high bay; moved back into mid bay later that day [???]
* 20 Dec 2021: Nosecone in [??]
* 22 Dec 2021: Tank section moved out of mid bay once again; crane attached, lifted off transport stand near high bay
* 22 Dec 2021: Nosecone moved out of high bay, tank section unhooked from crane after being placed on a shorter stand
* 23 Dec 2021: Tank section still waiting outside high bay, possibly being scrapped
* 28 Dec 2021: Nosecone still being worked on, S22 nc barrel section (5-rings) infront of it
* 28 Dec 2021: Tank section still waiting outside mid bay
* 29 Dec 2021: Tank section moved into mid bay (again)
* 17 Jan 2022: Tank section moved out of mid bay once again
* 20 Jan 2022: Tank section still outside mid bay
* 27 Jan 2022: Outside mid bay
* 28 Jan 2022: Production appearing to have paused
* 14 Feb 2022: S21 and S22: S22 tank section moved to high bay; S21 nosecone **reassigned** to S22; nosecone lifted and **stacked** onto S22 tank section in high bay
* 15 Feb 2022: S22 nosecone (ex S21) welded to its tank section
* 15 Feb 2022: Tanks section work remains paused
* 15 Apr 2022: Tank section finally being scrapped
* 16 Apr 2022: Scrapping continued
* 21 Apr 2022: At scrap yard; TPS tiles and white blanket torn off