SpaceX’s Starship rocket recently completed its second test flight, and one of the most striking visuals from the launch was the formation of “mach diamonds” or “shock diamonds” by its super-heavy rocket booster. This phenomenon occurs when there are significant pressure differences between two masses of air, leading to the formation of shock waves or expansion fans. While mach diamonds are typically seen in high-performance jets, the sight of them during the Starship launch was particularly impressive due to the 33 Raptor Vacuum engines working in unison.
The Starship system, consisting of a rocket booster and spacecraft, took off from SpaceX’s Starbase facility in Texas on November 18. In a significant achievement, the rocket booster successfully separated from the spacecraft, marking progress compared to the first test launch in April. However, the rocket booster later exploded over the Gulf of Mexico, and contact was lost with the spacecraft after it reached space.
The 33 Raptor Vacuum engines of the rocket booster generate a staggering 16.7 million pounds of thrust, making it more powerful than NASA’s Apollo-era Saturn V rocket. The exhaust from the engines, which burns methane with liquid oxygen, creates lower pressure than the atmosphere, resulting in the formation of shock diamonds.
Dr. Chris Combs, an aerodynamics professor, explained that the unique aspect of the Starship launch was the formation of a single mach diamond despite the large number of engines. Typically, a single engine or nozzle produces a shock diamond, but in this case, the engines acted as one, creating a larger mock diamond structure when viewed from a distance.
During the launch, the angle of the diamond changed as the rocket ascended, aligning with the rocket body. This change is due to the decreasing atmospheric pressure at higher altitudes. Combs emphasized that despite some considering the recent test a failure, it is important to view it as part of the ongoing development of a relatively immature technology. He acknowledged the ambitious and high-risk nature of the Starship project and emphasized the need to manage expectations while recognizing its potential.
Overall, the formation of shock diamonds during the Starship test flight was a visually stunning display of physics on a grand scale. The unique appearance of a merged mach diamond structure highlights the progress and challenges of SpaceX’s ambitious endeavor.