Introduction to SpaceX’s Ambitious Fourth Launch
For the fourth time in just over a year, SpaceX is gearing up to launch its colossal Starship rocket from the development hub in southern Texas, known as Starbase. Dubbed Flight 4, this mission is a significant step towards achieving the goal of creating a mostly reusable rocket.
Mission Overview: Flight 4 Details
Like its predecessors, Flight 4 will not carry a payload and will follow a suborbital trajectory. The scheduled liftoff is at 7:50 a.m. CDT (8:50 a.m. EDT, 1250 UTC), with a launch window of 120 minutes. Spaceflight Now will provide live coverage in collaboration with LabPadre starting at 7:00 a.m. EDT (1100 UTC).
Rocket Assembly and Objectives
Recently, SpaceX stacked the Ship upper stage (Ship 29) onto the Super Heavy Booster (Booster 11), forming the 121 m (397 ft) Starship rocket. Both components will be expended during the flight. The mission aims to demonstrate their future reuse capabilities. Elon Musk highlighted on social media that the main goal is to delve deeper into the atmosphere during reentry, focusing on max heating.
Technical Challenges and Enhancements
During Flight 3, the upper stage experienced uncontrolled rolling, preventing the relight of one of its six Raptor engines. Despite this, the rocket streamed high-definition reentry views via the Starlink satellite internet. SpaceX attributed the issue to valve clogging and has since added additional roll control thrusters and upgraded hardware for improved resilience.
Super Heavy Booster Adjustments
The previous Super Heavy Booster prematurely shut down six of its 13 Raptor engines during the boostback burn. This led to a loss of thrust during the landing burn. The cause was determined to be filter blockage in the liquid oxygen supply. For Flight 4 and future missions, SpaceX is enhancing propellant filtration capabilities inside the oxygen tanks.
Eyes on the Moon: NASA’s Involvement
Flight 4 is pivotal not just for SpaceX but also for NASA, which plans to use the Starship for the Artemis 3 mission targeted for September 2026. Lisa Watson-Morgan, the manager of the Human Landing System program, and her team are closely collaborating with SpaceX. They are working on the development of the rocket that will serve as the Moon lander for the Artemis missions.
Propellant Transfer Success
One notable success was the propellant transfer demonstration, shifting liquid oxygen from the ship’s header tank to the main upper stage LOX tank. This fulfilled a $53.2 million contract with NASA’s Space Technology Mission Directorate (STMD). SpaceX aims to conduct ship-to-ship propellant transfers as a critical component of its Artemis Moon landing mission.
Expansion and Future Launches
To facilitate multiple Starship missions, SpaceX is constructing a second launch tower at Starbase. Components are being manufactured at NASA’s Kennedy Space Center and shipped to Texas. The FAA is hosting public meetings to gather input on allowing up to 44 Starship launches annually from Launch Complex 39A.
Human Factors and Astronaut Involvement
SpaceX is also gathering input from NASA’s Astronaut Office to ensure the human-rated version of Starship meets all requirements. This includes interface design, control systems, and other functionalities. Recent integrated tests of pressurized spacesuits alongside Starship mockups have been promising.
Aiming for Shorter Turnarounds
SpaceX aims to shorten turnaround times between launches. Flight 2 followed 212 days after Flight 1, Flight 3 came 117 days after Flight 2, and Flight 4 is set just 84 days after Flight 3. The goal is to reach a monthly launch cadence, incorporating lessons from each flight to improve subsequent missions.
