SpaceX’s Starship Production facility in Boca Chica, Texas is basically filled with new and flight-proven Starships. The company is preparing its next round of major tests for its Starship rocket prototypes.
SpaceX is apparently building several Starship prototypes at a very rapid pace.
According to NASASpaceflight, parts built for the SN11 prototypes were spotted at SpaceX’s facility.
As a result, it is widely speculated that the SN8, SN9, SN10 and SN11 are all in production simultaneously.
The Evolution of Starship Prototypes
SpaceX spent the better part of a year building and conducting an array of tests to several prototypes.
The first Starship design unveiled by the company was the Starship Hopper. SpaceX conducted a series of tethered flight tests using the Raptor Engine.
Tethered flight tests is a form of flight testing whereby a machine is connected by a tether to the ground.
SpaceX then conducted an untethered hop test to the Starship Hopper on August 28, 2019. The Hopper launched 150m into the air using a single Raptor engine.
The successful test effectively proved that the Raptor can be integrated into a prototype.
This enabled SpaceX to start conducting tests with full-scale prototypes.
A cryogenic proof test is when a spacecraft of any kind is filled with cold liquid nitrogen to verify that its tanks can whistand flight pressures. In other, it is a standard test used by engineers to see if the launch vehicle can hold up to extreme temperatures. Liquid nitrogen has a boiling point of -195.8 Celsius.
Next, SpaceX rolled out its Starship SN4 prototype. After undergoing a successful cryogenic proof test, the Raptor engine powering the SN4 failed during the static fire test and the prototype exploded on May 28, 2020.
A static fire test is the process of firing the engines of a rocket at full thrust. The engine is fired for a few seconds while the launch vehicle remains attached to the launch mount.
A static fire test is essentially a quality-control and risk assessment test. It tests the durability of the rocket’s first stage engines. It also examines the countdown process. This means fueling the rocket’s first and second stages. Secondly, the ability of the payload to run off on internal power. And Thirdly, the ability to communicate with ground control before liftoff.
The same thing applied with the SN6. Both the SN5 and SN6 prototypes successfully hopped barely 30 days apart.
Although SpaceX still plans to hop the SN5 again and may hop the SN6 twice, the company’s priorities lay elsewhere.
SpaceX is now shifting to high-altitude, high-velocity flight tests and the adoption of a new steel alloy. The company is effectively adopting a 304L-class steel alloy instead of the 301 stainless steel. The latter was used to build the SN1 prototype through SN6.
SpaceX’s first 304L test will be used on the Starship SN7. The SN7 test campaign is scheduled to begin today at 10pm EDT.
Assuming everything goes according to plan, this will prove that the 304L steel alloy is superior to 301.
It will be then used to build the Starship SN8, which will make it the first full new-alloy prototype. The SN8 will also be fully outfitted with a nosecone and header tanks before SpaceX undertakes tests on it.
All in all, SpaceX has enough hardware on hand to fully assemble the SN8 and SN9 prototypes.
Starship is indeed SpaceX’s priority!