Ship 20

History

Construction

The first component of Ship 20 (originally known as SN20) was the leg skirt which was spotted on March 7, 2021. It was reported by NASASpaceFlight.com that SN20 with BN3 would attempt an orbital test launch by July 1, 2021.

According to a filing with the FCC for the planned test flight, BN3 & SN20 would launch from Boca Chica with the Super Heavy booster then performing a partial return, touching down 20 miles/32.1 km off shore. SN20 would continue on its flight path between the islands in the Caribbean before performing an expendable splash down landing 100km north of Kauai in Hawaii. The soft landing is scheduled to take place after Starship performs a successful bellyflop, flip and landing manoeuvre.

In late June SN20 was re-designated from SN20 to Ship 20, with stacking operations underway in the Mid Bay not long after. The launch appeared to take on new urgency with Elon Musk ordering several hundred of SpaceX’s employees at Hawthorne to relocate to Boca Chica to speed up the development of Ship 20 and Booster 4, along with the Orbital Launch Platform to have the Starship system on the pad by August 5.

In early August Ship 20 had the flaps fitted to the dome and aft section, before being moved to the High Bay in preparation for final stacking on August 3 which had been vacated by Booster 4’s move to the Orbital Launch Pad. The dome was stacked in the early hours of August 4.

Testing

On August 5, Ship 20 was rolled out to the Orbital Launch Pad. Elon Musk noted that stacking the ship onto the booster had to be delayed due to higher than anticipated winds, but SpaceX took the opportunity to continue to attach more Thermal Protection Tiles to some of the exposed sections, completing tiling by 4:40am. The final stack took place on August 6 at 7:56am, marking the first time a Super Heavy Booster and the second stage Starship had been stacked, representing the largest rocket in human history to date.

Ship 20 remained stacked to Booster 4 for a few hours before being unstacked and returned to the production site for further works, including having its engines removed on August 7. At the same time it appeared that an inspection on the thermal protection tiles was being performed, as they were being marked with coloured tape. On August 11, Ship 20 was moved out of the High Bay.

Ship 20 returned to the launch site on August 13, despite having some of the TPS tiles removed and yet to be replaced. On August 17 it was lifted onto Suborbital Pad B, it is assumed that it will go through a period of cryogenic testing and static fires before it is again lifted on top of Booster 4. By the end of August the engineers had made visible progress on replacing and preparing the TPS tiles ahead of its test flight.

September 5 saw three new raptors (69, 73 and 78) arrive at the launch site, presumably for installation on Ship 20, with installation of the first being prepared for not long after with the  replacement of TPS tiles on the nosecone nearing completion. Ship 20 conducted an ambient pressure test, with a header tank vent resulting in several of the thermal protection tiles being dislodged as reported by Elon. During the night of September 27/28 the first cryogenic pressure test took place. A close up photo was taken after the testing by Nic Ansuini showed what he believed was the cause – gas being caught under the thermal blanket throwing some of the tiles loose.

On the night of September 29/30, Ship 20 underwent a second cryogenic pressure test. At 11:39pm on October 18, Ship 20 saw a preburner test with a brief flash observed on the NASA Space Flight stream. The first static fire test for Ship 20 took place on October 21 at 7:16pm with a single raptor sea level engine and one vacuum engine fitted and a second took place at 8:18pm. The static fires were observed by Starship Gazer, NASA Spaceflight Now and Austin Barnard as well as SpaceX releasing their own footage.

Two vacuum raptor engines were spotted being moved to the launch site on October 29, and both were installed onto Ship 20 after arrival. The first six engine static fire test took place on November 12 and was recorded by NASASpaceFlight as well as Starship Gazer. Scott Manley observed that the test firing had more thrust then any other rocket in the world. A flap test took place on November 16.

Elon Musk gave an interview to the SSB & BPA Joint Fall Meeting on November 17 (watch here), revealing more details about the Starship program including a targeted launch date of January/February 2022 for S20/B4. A static fire test was planned for December 1, but was aborted close to ignition.

On December 15 it was noticed that the crane attach points were being removed, and work on the nose cone TPS continued so that by December 24 the crane attachment points had been covered. A new static fire took place on December 29 which was observed by the NASA Spaceflight stream.

Milestones

All dates & times are local unless otherwise indicated.