As part of its Artemis program testing, SpaceX attempted to ignite its Raptor engine last month after cooling its components to simulate lunar landing temperatures. The "Raptor" engine will be the largest engine of its kind launched on the moon when the "Starship" lands. The August test video released yesterday afternoon comes as SpaceX races against time to conduct the second flight of the "Starship" rocket.
The rocket was destacked yesterday at the company's test site in Boca Chica, Texas, the same day SpaceX released test footage of the engines that will launch on a second-stage lunar Starship variant. This vehicle is the first choice for NASA's plan to develop a human colony on Mars. Kathy Leuders, a former NASA official who now works for SpaceX, also believes that the second Starship test launch will be conducted as soon as October.
The test launch was coordinated with NASA, which shared more details in a blog post. NASA revealed that SpaceX demonstrated the engine’s throttle curve and sturdy construction in 2021. The latest video shared by SpaceX is of an engine test last month. Since the Raptor engine is cooled to conditions that match temperatures in a vacuum, its main focus is on the engine's construction. Moon temperatures can be as low as minus 130 degrees Celsius, and the engine is made up of thousands of parts and its thermal profile may not be able to withstand extreme conditions.
The Raptor is the undisputed star of the Starship program, and most of the upgrades to the full-stack Starship rocket after SpaceX's test attempt in April involved the engine. However, these upgrades involve powering 33 engines simultaneously, which is more complex than starting the engines of a lunar starship. SpaceX has also conducted multiple tests of the second-stage Starship, and demonstrated the Raptor’s lunar descent ignition curve to NASA for the first time during this test event.
Since 2021 and 2023, SpaceX has also developed a streamlined and more powerful Raptor called Raptor 2. All engines built over the past few months have adopted the new design, so it's likely that yesterday's test footage featured a Raptor 2 as well.
Last month's Raptor 2 freezing test lasted just five seconds and was conducted during daylight hours. According to NASA, Starship's full sustained descent is expected to last 281 seconds, and 5 seconds is only a fraction of that. SpaceX demonstrated this capability during a 2021 test, impressing NASA.
SpaceX Starbase general manager Kathy Leuders, who oversees the test, launch and development base, is confident that Starship will conduct its second orbital test flight next month. Ms. Leuders shared the latest details of SpaceX's work with the FAA to create space for a launch license renewal that would include a second test flight.
SpaceX won't conduct test flights until it's ready, and Leuders shared that installing the flight termination system is one of the last steps before a rocket takes off. Installing the system also typically sets a time limit for rocket launches.