SpaceX founder Elon Musk also hopes that the interstellar spacecraft will fly to Mars, which also requires mastering space and refueling. NASA may soon rely on starships and other giant commercial rockets to launch astronauts from Earth. The Trump administration proposes to cancel NASA's space launch system rockets after two other commercial options to reduce costs.

In any case, SpaceX must prove that it has overcome the setbacks encountered in the previous two test flights. The two flights took place around the same time (eight minutes after launch) at the end of the engine launch on board. SpaceX investigators working under the supervision of the Federal Aviation Administration determined that the Starship test flight failed in January after a propellant leak caused a fire in the stern carriage or attic in the rocket chamber. This led to early shutdown and ultimately decomposition of the rocket engine.

The engineer concluded that the leak was likely caused by vibrations during the ship's climb into space. The vibration resonates with the natural frequency of the vehicle, thereby enhancing shaking beyond SpaceX's predicted levels. During its next test flight on March 6, SpaceX made changes to the ship's feed line, adjusted the Raptor engine's routing fuel, adjusted the propellant temperature, and flew the engine under the new throttle settings.

But this doesn't solve the problem. The Starship's engine was cut off again too early and the rocket broke before it fell to Earth. SpaceX said the "vibrant events" after the Starship resulted in the loss of several Raptor engines, followed by loss of attitude control and communication with the ship.

Similarities between the two failures suggest that the upgraded "Block 2" version of Starship may have been a design problem for its debut in January and will fly again in March. The Starship 2 is slightly taller than the Ship SpaceX used in the first six rocket carriers, with redesigned flaps, improved batteries and aviation equipment, especially the ship's new fuel feed line system for the Raptor vacuum engine.

SpaceX has not released a finding of the Flight 8 failure, and the FAA has not issued a launch license for Flight 9. Similarly, SpaceX has not released any information about changes made to Starship by its flight next week.

What we know about the Starship Vehicle (designated ship 35) for Flight 9 is that it took several attempts to complete the full vein test. SpaceX completed a single-engine electrostatic fire on April 30, simulating the restart of the Raptor engine in space. Then, on May 1, SpaceX missed six-engine tests before reaching the planned 60-second duration. The video captured by the media from the observation test showed flashes in the engine plume and found at least one piece of debris was ingested from the flame ditch under the ship.

SpaceX ground crews returned 35 ships to production sites several miles away, perhaps to replace the damaged engine, and then returned Starship to the test station over the weekend for a successful engine shot on Monday.

Now the ship will return to the Constellation construction site, where technicians will make final preparations for Flight 9. These final missions may include loading the simulated Starlink broadband satellite into the payload compartment on the ship and touching the rocket's heat shield.

These are two elements of the Starship that SpaceX engineers are eager to showcase on Flight 9, not just solving problems in the last two missions. These failures prevented the spacecraft from testing its satellite deployers and upgraded thermal insulation panels, designed to make temperatures higher than 2,600 degrees Fahrenheit (1,430 degrees Celsius) during reentry.

This story originally appeared in ARS Technica.