NASA fired the four engines of its towering Space Launch System rocket for the first time Saturday after a decade of development, but the engines were cut off well short of the intended duration, a sign that something went wrong.

NASA had been hoping to fire the four RS-25 rocket engines for eight minutes, but officials ended the test after about 60 seconds. It was not immediately clear what went wrong or what effect that would have on NASA’s schedule. Space agency officials had hoped the rocket would fly for the first time by the end of this year but that appeared to be uncertain as the reasons for the early shutdown remain unknown.

“We got lots of data that we’re going to go through and be able to sort through and get to a point where we can make determinations as to whether or not launching in 2021 is a possibility or not,” NASA Administrator Jim Bridenstine said at a briefing hours after the test.

Before the test, officials said they would need the engines to fire for at least two minutes to get all the data they needed to consider the test a success. At the briefing, NASA officials acknowledged that that threshold had not been met and that they didn’t yet know what caused the problem, or how long it would take to fix.

John Honeycutt, the SLS rocket program manager, confirmed there was an “MCF” reading, or a “major component failure,” a potentially significant issue. But he said, “I don’t know much more about that than you do. … Any parameter that went awry on the rocket could send that failure ID.”

He said it was unclear whether the problem was related to the rocket’s hardware, software or a faulty sensor. “I think we need to do our due diligence and go look at the data that we’ve collected,” he said.


The test was supposed to simulate a full-duration launch with the core stage – the main part of the rocket – clamped down on a test stand at NASA’s Stennis Space Center near Bay St. Louis, Miss. The ignition was successful, but the engines ran for just over a minute before they shut down.

During the briefing, Honeycutt said controllers saw a “flash” around one of the engines just before the shut down but said he didn’t have any information about what caused the flash or if it caused any damage to the engine.

The truncated test is another setback for a program that for years has suffered all sorts of problems, delays and more than $1 billion in cost overruns. It’s also yet another stumble by Boeing, the prime contractor on the core stage. The aerospace giant has had a series of problems in its space and defense divisions in addition to the crashes of its 737 Max airplanes.

Frustrated with the slow pace of progress, Vice President Mike Pence in 2019 threatened to sideline the SLS rocket, which has long been derided as a vehicle better suited for job creation than exploration. But NASA said it recently made significant progress, and on Saturday, the agency and Boeing had hoped to declare a successful test that would place the program on course to return astronauts to the moon for the first time since 1972.

“This powerful rocket is going to put us in a position to be ready to support the agency’s, and the country’s, deep space mission to the moon and beyond,” Honeycutt had said before the test.

The SLS has been described as more powerful than the mighty Saturn V rocket that launched the Apollo astronauts to the moon. The SLS’s core stage stands 212 feet tall and weighs more than 2.3 million pounds. In addition to the four RS-25 engines, it will have two solid rocket boosters strapped to the side. The avionics computers have 18 miles of cabling and more than 500 sensors. And fully fueling the rocket with 733,000 gallons of supercooled liquid hydrogen and liquid oxygen requires 114 tanker trucks.


But the road to get to Saturday’s abbreviated test has been a long one. Since the SLS program officially began in 2011, numerous government watchdog reports have catalogued a series of technical missteps, wasteful spending and lax oversight. One Government Accountability Office report found that NASA had paid Boeing tens of millions of dollars in “award fees” for scoring high on evaluations, despite poor performance.

For years, critics mocked the rocket as the “Senate Launch System” for the jobs it creates in key congressional districts.

In the meantime, several private companies are developing heavy-lift rockets of their own, which would be less expensive and use newer technology. Unlike SpaceX, which builds rockets that can fly multiple times, the first stage of the SLS, and its engines, would be discarded into the ocean after each use.

And those engines are not cheap. Aerojet Rocketdyne, which would be acquired by Lockheed Martin in a deal set to close later this year, has a $3.5 billion contract from NASA to deliver 24 of the engines through 2029.

“The whole space ecosystem has shifted tremendously,” said Andrew Aldrin, the director of the International Space University-Center for Space Entrepreneurship at Florida Tech. “Is this going to be the last time we have a big government program to build a huge launch vehicle? That’s a real question.”

Pence’s threat to sideline the rocket was intended as a warning to Boeing that its hold on the program was not unchallengeable.


“We’re not committed to any one contractor. If our current contractors can’t meet this objective, then we’ll find ones that will,” he said. “If commercial rockets are the only way to get American astronauts to the moon in the next five years, then commercial rockets it will be.”

Since then, NASA and Boeing have said the program has made a lot of progress, and it completed a series of tests known as the “Green Run” to prepare it for launch. Saturday’s engine test was to have been the culmination of that campaign, with the core stage scheduled to be shipped next month to the Kennedy Space Center to be integrated with the Orion crew capsule. But now the schedule is uncertain.

Despite the setback, Bridenstine tried to put a positive spin on the day.

“I just want to say the amount of progress that we’ve made here today is remarkable,” he said. “And no, this is not a failure. This is a test, and we tested today in a way that is meaningful, where we’re going to learn more and more and we’re gonna we’re going to make adjustments, and we’re gonna fly to the moon.”