SpaceX Launches Starship’s Final Test Flight of 2023

SpaceX successfully launched the eleventh full-scale test flight of its Starship rocket on Monday evening, marking the end of a challenging year for the company. The launch took place from South Texas, with the rocket aiming for a one-hour flight trajectory that concluded in the Indian Ocean. Liftoff occurred at 6:15 PM CDT (7:15 PM EDT; 23:15 UTC), as SpaceX operated within a 75-minute launch window.

The Super Heavy booster, equipped with the Starship upper stage, lifted off with a staggering thrust of approximately 16.7 million pounds. This power is 60 percent more than that of the Soviet N1, the second-largest rocket in history. Notably, this flight utilized a previously flown Super Heavy booster that had successfully launched and landed during a test in March.

Flight Details and Objectives

The test flight followed a trajectory over the Gulf of Mexico, similar to the previous August mission. Two and a half minutes into the flight, the Super Heavy booster was scheduled to separate from the upper stage. As the two stages parted, the six engines on the Starship upper stage ignited to propel the rocket further into space.

SpaceX engineers monitored the flight closely, particularly the new 13-5-3 landing burn engine configuration for the booster. This sequence aims to enhance resilience against engine failures by transitioning from 13 to five engines before relying on three center engines for the final landing phase. The primary objective of this flight was to gather data on real-world vehicle dynamics during engine shutdowns.

Unlike previous missions, the booster targeted a splashdown in the Gulf of Mexico rather than a return to the launch pad for recovery. In orbit, Starship was set to deploy eight Starlink satellite simulators that would follow the same suborbital path and ultimately burn up upon re-entry into the atmosphere.

Testing the Heat Shield

A critical aspect of this mission involved testing Starship’s heat shield, a focus for SpaceX throughout the year. The initial three flights faced challenges with re-entry, but the August flight succeeded in achieving a controlled re-entry and splashdown northwest of Australia. Engineers noted several lessons learned, particularly regarding the replacement of ceramic tiles with metallic insulators.

For this flight, SpaceX removed tiles from specific areas of the Starship to intentionally stress-test vulnerable sections of the vehicle. Some of these tiles were removed from spots where they were directly bonded to the stainless-steel skin without a backup ablative layer. The goal is to identify an optimal tile design that can withstand the extreme conditions during re-entry, where temperatures can soar to 2,600° Fahrenheit (1,430° Celsius).

Future flights are expected to see the Starship returning to the launch site at Starbase, where engineers plan to catch the vehicle using tower arms, similar to the recovery methods employed for the Super Heavy booster. However, this capability is still a few flights away.

As 2023 concludes, this test flight represents the last for the current version of Starship. SpaceX is preparing for the introduction of Version 3, which is anticipated to debut in early 2026. This new iteration will feature upgraded Raptor engines and larger propellant tanks, along with capabilities for in-orbit refueling.

NASA is counting on an increased flight rate from SpaceX to fulfill its contract for a human-rated lander as part of the Artemis lunar program. With contracts valued at over $4 billion, SpaceX is focused on demonstrating reliable and rapid reuse of Starship, crucial for future missions to the Moon and Mars.

In preparation for these ambitious goals, SpaceX is building additional launch infrastructure, including a second launch pad at Starbase and new facilities in Florida. The upcoming test of in-orbit refueling remains a critical challenge as the company moves forward with its plans for deep space exploration.