From Joe Tegtmeyer.

As we get closer to SpaceX Starships flight #7 in early January 2025, I thought it might be helpful to go over many of the key milestones and objectives of this first mission with the second generation of Starship and then go into more detail about the aerodynamics of reentry and how this relates to many of the upgrades to the heat shield and flap designs of this new ship version.

The redesign of the ship forward flaps is something that has been talked about over the past few years and most recently with Tim Dodd (The Everyday Astronaut) and Elon Musk in June 2024 during a tour of the launch site ahead of flight #4. The original design had significant heat flux issues causing burn-through of the flaps and compromising parts of the ship structure. This also presented some undesirable aerodynamic forces on the ship which complicated controllability and pitch attitude during the reentry phase of flight.

In this video, we discuss the basics of the ship aerodynamics, atmospheric composition and the four main phases of flight (hypersonic, supersonic, transonic and sub-sonic), axis definitions, Center of Pressure and Center of Gravity, stability, underlying equations and discussion of which variables can be modified and the effects of these modifications.

My intent with this video is to prepare the viewer to understand many of the huge changes with the Starship debuting on flight 7 and the underlying reasons for the significant changes. Ultimately, I hope this helps put into context what SpaceX is attempting to master with the development of the Starship program.