SpaceX set to launch 4th test flight of Starship rocket — critical ...

Nicole Mortillaro · CBC News

· Posted: Jun 06, 2024 4:00 AM EDT | Last Updated: 27 minutes ago

Hot on the heels of the successful crewed launch of Boeing's new CST-100 Starliner on Wednesday, we have another rocket launch: This time it's SpaceX's massive Starship.

This is the fourth test flight of the rocket — which will be uncrewed — that SpaceX founder Elon Musk hopes will one day take astronauts to Mars.

The 120-minute launch window opens at 8 a.m. ET. This will be a suborbital flight, meaning that it won't go around Earth. Instead, it aims to have a soft water landing in the Indian Ocean about an hour after liftoff from the launch site in Boca Chica, Texas. 

Getting Starship to work as it should isn't just a flight of fancy for SpaceX: It's a critical component for NASA's return to the moon. 

A variation of Starship, called the Human Landing System, will dock with the space agency's Orion spacecraft for the planned 2026 Artemis III mission, then shuttle a pair of astronauts to the lunar surface.

Starship is made up of two stages: the first stage is the Super Heavy rocket, while the second stage is also referred to as Starship. 

Just as with SpaceX's Falcon 9 rocket, the first stage is meant to be reusable and return to Earth shortly after launching. The second stage would house cargo — or astronauts� in the case of the Human Landing System — and also be fully reusable.

SpaceX has met many of its goals in testing this behemoth. The first, in April 2023, was a test to see if it would be capable of lifting off the pad, and it did. However, it severely damaged the launch pad in doing so, and blew up four minutes into its flight.

In the second launch, in November 2023, SpaceX tested its "hot staging" where the rocket of the second stage ignites just before the pair separate. While that was successful, the first stage was lost in an explosion, and the second stage made it to suborbit before it, too, exploded.

The third launch, on March 14, was a test of several more components, including a boostback burn where the first stage uses 13 of its 33 engines to guide it to where it would land (in this case, it would make a water landing in the Gulf of Mexico). However, it had engine issues and failed to achieve a soft water landing.

Starship also reached its full ascent and began to re-enter the atmosphere — which was a test of the tiles that protect the spacecraft as it heats up during re-entry — but an unplanned roll caused it to break up. It also opened and closed its payload bay door.

WATCH | The moment SpaceX's Starship re-entered Earth's atmosphere in March: 

Perhaps most importantly for NASA , it tested a propellant transfer within the rocket. For the Artemis missions to the moon, SpaceX will have to prove that it can do this between two ships. This was just the first step.

While not everything went as planned in the last launch, SpaceX regarded it as a successful testing of crucial components. That's SpaceX's modus operandi: Test things in the real world.

"SpaceX is doing what SpaceX is good at, which is getting the flight test off and running, and learning from the flight test, taking what they learned and get it into the next one," said Dan Dumbacher, an engineer and former NASA official who is now the CEO of the American Institute of Aeronautics and Astronautics.

WATCH | Why SpaceX rocket explosion isn't hampering plans for Mars mission: 

For this test, SpaceX's primary goals are to successfully conduct the landing burn of the Super Heavy booster, once again, aiming to softly splash down in the Gulf of Mexico.

As well, it hopes to achieve a successful re-entry of Starship, where it will splash down in the Indian Ocean.

Canadian Jordan Bimm, a postdoctoral researcher at the University of Chicago and a space historian, says there's a lot riding on SpaceX's latest uncrewed test flight of Starship.

"So far, the public has accepted the iterative design approach, and have tolerated the failure-as-progress-toward-success model," he said. "A failure to push further towards a complete, successful flight than previous tests could erode public acceptance and tolerance of the iterative approach."