SpaceX's Starship SN4 prototype explodes after rocket engine test

SpaceX's latest Starship prototype exploded just after an engine test Friday (May 29), erupting in a dramatic fireball at the spaceflight company's South Texas proving grounds.

The Starship SN4 prototype exploded at about 1:49 p.m. CDT (2:49 p.m. EDT/1849 GMT) at SpaceX's test facility near Boca Chica, Texas according to a video provided by the South Padre Island tourism site SPadre.com. The explosion occurred about a minute after a short test of its Raptor rocket engine, but it was unclear what caused the conflagration.

SpaceX's Starship SN4 rocket prototype explodes on its test stand near Boca Chica, Texas on May 29, 2020. (Image credit: Spadre.com)

SpaceX successfully test-fired the Starship SN4 vehicle yesterday as part of its preparations for an upcoming launch test that could have carried the rocket about 500 feet (150 meters) up. That same day, SpaceX received a launch license for its Starship tests from the Federal Aviation Administration.

As its name suggests, the Starship SN4 vehicle is the latest in a series of stainless steel prototypes SpaceX has built to test technologies required for a truly massive space launch system: the 165-foot-tall (50 meters) Starship rocket and its Super Heavy megabooster. That vehicle is the one SpaceX hopes will carry up to 100 people at a time to space and, eventually, on to Mars.

Last month, NASA picked SpaceX's Starship as one of three commercial spacecraft that could land astronauts on the moon for the agency's Artemis program in 2024.

While several of the Starship prototypes of exploded, SpaceX CEO Elon Musk has said the company is committed to learning from each test and forging ahead.

The company's first prototype, the Starship Mk1, was destroyed during a pressure test in November 2019. Its successor SN1 was lost in similar test in February. The next iteration, SN2, successfully passed that pressure test in March. The SN3 prototype, meanwhile, collapsed during testing in April. Musk later said that leaky valves were the culprit and that it would be fixed on the next vehicle.

The Starship SN4 was by far the longest-lived and most-tested Starship prototype to date. Today's static-fire engine test was the fifth for the vehicle, the most of any to date.

SpaceX was already building another Starship prototype, the SN5, at the time of today's SN4 failure. That vehicle will likely take center stage for the company's next round of tests.

You can see another view of the explosion in the video below from NASASpaceflight.com.

SpaceX's Starship SN4 explosion comes as the company is counting down to another major launch on a different rocket.

A SpaceX Falcon 9 rocketand Crew Dragon spacecraft are scheduled to launch two NASA astronauts to the International Space Station in a historic test flight.

The mission, called Demo-2, is currently set to launch no earlier than Saturday (May 30) at 3:22 p.m. EDT (1922 GMT) from NASA's Kennedy Space Center in Florida. It will be SpaceX's first human spaceflight, and the first orbital crewed launch from the United States since NASA's space shuttle fleet retired in July 2011.

Bad weather prevented the Demo-2 mission's initial launch attempt on Wednesday (May 27). SpaceX has backup days on through Sunday (May 30) before likely standing down for a few days, NASA officials have said.

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Tariq is the Editor-in-Chief of Space.com and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became Space.com's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining Space.com, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at Space.com and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.

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10 Comments Comment from the forums

ngifford

Anyone else feel like this whole rocket program is like watching a train wreck in slow motion? The prototypes look amateurish, and the launch facility looks amateurish. This is not going to end well.
Reply
Wolfshadw

Looks can be deceiving. If they work, who cares how they look?

-Wolf sends

Edit:

Reply
Douglas E Knapp

It's called a prototype for a reason. Have you ever seen the very first apple computer? Did look like an Iphone to you? Why put spit and polish on something that is likely to fail? That would be nothing but a waste of money. Look at the astronaut launch, they look really cool and the finished starship will too, once they finish it.
Reply
HamyMac

Must be a fun wait til Saturday for the other guys then, eh?
Reply
Phantom-e

The launch facility, specifically launch pad 39A has a vast historical legacy. It was used to send the first Astronauts to the moon, so "looks" aren't everything. Most prototypes lack "window dressing", so don't go by the looks. A test on a prototype isn't doom if it fails, but helps to reveal flaws, learn from them and fix them.
Reply
Brian

You know darn well that things are going BOOM!
Why bother with good looking facilities and a shiny rocket.
That's for the finalized design.
People forget Redstone?
Reply
2NYaz

ngifford said:
Anyone else feel like this whole rocket program is like watching a train wreck in slow motion? The prototypes look amateurish, and the launch facility looks amateurish. This is not going to end well.
Sir, Your not understanding the full scope of this engineering? In Research and Development no one plans to fail and failures happen all the time. In this development of SN4 rocket engine Reliability of a Successful Firing is what you gain in knowledge so when the engine is fully developed what made this failure will not occur again. Whatever the cause Make Dam Sure it is not repeated. In aerospace there is a term called Murphy's Law. If something is going to go wrong it will and that's when everyone feels it's OK to GO too. Your might agree that the SS Main Engines worked well on all the Space Shuttles. What you don't know is how many failures we had before we brought them to perfection.
Reply
ChrisA

2NYaz said:
Sir, Your not understanding the full scope of this engineering? In Research and Development no one plans to fail and failures happen all the time....

Actually this is NOT how modern R&D works. Elon Musk is using a very different method that has not been used for rocket development since the 1940s. Today we tend to finish the engineering BEFORE we build anything and it generally just works. SpaceX is building before they have a final design. Blowing up four rockets of this size in a row is unheard up today. It is likely he will lose another four.

He might save money doing it this way, who knows. But this is far from the way thngs are typically done.

My guess is that he will have to change his method
Reply
annodomini2

ngifford said:
Anyone else feel like this whole rocket program is like watching a train wreck in slow motion? The prototypes look amateurish, and the launch facility looks amateurish. This is not going to end well.

They are using a different development methodology known as Agile, fail fast and fail often.

If you find your weaknesses early it is usually cheaper and more efficient.

There are always failures when you are pushing the boundaries of engineering.

The other thing is they are (for better or worse) doing it in the public eye, most developments have failures, SpaceX are choosing to publish them.
Reply
HamyMac

Ask yourself why a company that has hundreds of launches under its belt thought that delivering 6million kg of thrust to a concrete platform, with nothing but a shower of water to diffuse that power, would not disintegrate the launch pad and scatter the debris far and wide and why they would not anticipate that at least some of that debris would be blown in the direction of the ship itself and damage the engines during take-off, as it most obviously did.
I think the answer is cost-cutting or complete stupidity. If you can plan a trajectory to Mars and beyond, but cannot anticipate the trajectory of a large amount of concrete scatteting during the 'unscheduled disassembly' of the launch pad, then should you be launching at all?
Personally, I love the Starship, the concept and the sheer audacity of it and I can see the advantages that it could give us, the teflon pan buying public, but if someone thinks they can put a bomb under a spaceship and not expect or plan for the kind of debris we all saw, then I'm not sure I'd want to book a flight with them until someone else was in charge of health and safety.
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