On Tuesday, SpaceX tested its Super Heavy rocket for about 12 seconds, making it the longest-duration massive booster launch yet. The test, which ignited 11 of the Raptor’s 33 rocket engines, came as SpaceX continues to work toward an orbital launch attempt for the Super Heavy first stage and Starship upper stage.
Earlier this month, SpaceX fired 14 Raptor engines at this booster for a few seconds, so Tuesday’s test didn’t set a new record for the number of engines tested. However, this “long-duration” launch is the longest period of time that several Raptor engines have been fired at once.
So what happens now? The path to orbit for SpaceX and the Starship launch system is not clear. Previously, the founder of SpaceX Elon Musk said The next step was to fire a subset of the Super Heavy’s triggers for about 20 seconds for a self-stress test. This method of pressurizing fuel tanks uses gases generated on board the rocket instead of separately loaded inert gases such as helium.
Tuesday’s test may have been a slightly shorter version of the self-stress test — 12 seconds instead of 20 — or it could have been something else. The company takes an iterative approach to design and development for the Starship and the Super Heavy first stage, so its test plans are seamless, not unlike cryogenic rocket propellants.
In all likelihood, SpaceX still has two primary tests to complete before launching the joint Super Heavy rocket and Starship upper stage from the company’s Starbus facility in south Texas. SpaceX is expected to run at least a short-duration test run of all 33 Raptor engines simultaneously to gain confidence in the complex whole of fuel plumbing and pressurization of the rocket’s propulsion system. Then the Starship’s upper stage will be stacked on top of the Super Heavy, and the combined vehicles must complete a rehearsal.
What seems clear is that SpaceX is maturing its approach to working with spacecraft engineering, as recent tests, including Tuesday’s, have ended without any apparent failures.
After completing all the technical preparations, SpaceX must also obtain a launch authorization from the Federal Aviation Administration, which is in the process but not yet completed. While it is still theoretically possible for Starship to attempt an orbital launch in December, there is a growing possibility that the test flight will slip into the early part of 2023.