S39.1 is test tank located at Massey Outpost and undergoing testing. It is the 18th 9m diameter test tank constructed by SpaceX and first for the Block 3 ship design. While the designation S39.1 has not been seen on any sections when rolled into stacking of the tank, a label for 'S39.1 mid barrel' was previously spotted in May 2025[1] indicating that the designation for the first Block 3 Test Tank would likely be S39.1.
History[]
On the 24th of August 2025 a triple barrel was moved into MB2, followed by a triple barrel forward section on the 26th, which was stacked on the triple barrel on the 27th, commencing stacking. Stacking was completed on November 8th 2025 and the test article was moved into Starfactory later the same day.
S39.1 was rolled out to the Massey Outpost ahead of testing to verify the design of the new Block 3 aft on November 25th, 2025.
Timeline[]
- May 2025: S39.1 spotted in Starfactory
- 24 Aug: S39.1 M:3 moved into MB2
- 26 Aug: S29.1 FX:3 moved into MB2
- 11 Oct: Upper section moved into MB2
- 27 Aug: S39.1 FX:3 stacked on M:3
- 6 Nov: S39.1 moved out of SFC
- 6 Nov: S39.1 AX:4 moved out of SFC
- 7 Nov: S39.1 AX:4 moved into MB2 and lifted onto turntable
- 7 Nov: S39.1 F:6 moved into MB2
- 8 Nov: S39.1 F:6 stacked atop AX:4 creating F:10
- 8 Nov: S39.1 moved to Starfactory
- 19/20 Nov: TT18 S39.1 moved out of SFC, into MB2 and lifted onto the Ship thrust sim
- 25 Nov: S39.1 rolled from Megabay 2 to Massey Outpost
- 4 Dec: S39.1 cryo
- 5 Dec: S39.1 cryo
- 6 Dec: S39.1 cryo
Testing Campaign[]
| Date | Test type | Outcome | Details |
|---|---|---|---|
| 4 December 2025 | Cryogenic proof test | Success | S39.1 conducted a cryogenic proof test. |
| 5 December 2025 | Cryogenic proof test | Success | S39.1 conducted a cryogenic proof test. |
| 6 December 2025 | Cryogenic proof test | Success | S39.1 conducted a cryogenic proof test. |
Gallery[]
