Photo by: NASA


NASA’s Giant Rocket Test Fails (Sort Of)

It was all supposed to be great. On January 16th, NASA performed its first major test run in a long, long time. It was a test for the core stage of its upcoming Space Launch System (SLS), a beast of a rocket that will carry astronauts to the Moon, Mars, and more.

January 29, 2021

At over 200 feet long and 27 feet wide, the core stage and its four engines will heave the rocket off the ground, the hardest part of a launch. The test was supposed to last nearly 8 minutes, the length of time that the main engines will have to perform their launch duties. But only 50 seconds into the test, the onboard computer system signaled that something was going very wrong. At 67 seconds, the test ended.

Photo by: NASA


While the test did abort early, nothing blew up – which is definitely a “win” when it comes to rocket testing. Indeed, analysis of the test data discovered that the fault happened when the engines were beginning to gimbal, or change direction, a crucial part of the launch. However, the computer flagged it because a sensor on the hydraulics reached a safety threshold. But that threshold was intentionally conservative for the test. If the same situation happened during an actual flight, the engines would still perform as expected, and not blow up (hopefully).

NASA and its partner Aerojet Rocketdyne, who is building the core stage, are pouring over the data from the test to fully diagnose the issue, and determine if they can swap out one of the engines (which means they could do a new test in as little as a week) or if they need to start from scratch.

This exactly why we do tests – to find potential problems and fix them safely.

But on paper, the SLS (which will be the biggest, most powerful rocket ever made) was supposed to be easy. NASA hasn’t designed a rocket since the 1970’s, so the SLS is supposed to carry on the legacy of the Space Shuttle. The RS-25 engines are the same ones used in that program, and visually and structurally the SLS looks very similar to the Space Shuttle’s external fuel tank. But as this recent test showed, rockets are never easy.

And now the entire SLS program is now potentially in jeopardy. It’s already 33% over budget (currently sitting at $17 billion spent and counting) and late (the first full launch was supposed to happen three years ago). The new Biden administration hasn’t announced their plans for the space program, and crucially whether they will continue the Artemis project, which is supposed to deliver astronauts to the moon in 2024. But the entire Artemis program needs a lift, and the SLS was supposed to be the space delivery vehicle of the future.

Paul M. Sutter

Paul M. Sutter is an astrophysicist at Stony Brook University and the Flatiron Institute, host of Ask a Spaceman and Space Radio, and author of How to Die in Space.

Next Up

Check Out NASA’s DART Mission

It’s like “Armageddon” but in real life.

Liftoff of NASA and SpaceX Crew-2!

The NASA and SpaceX Crew-2 mission launched on Friday, April 23 at 5:49A ET from the NASA Launch Complex 39A. This historic milestone marks the second operational mission of SpaceX’s Crew Dragon. Onboard was NASA astronaut Shane Kimbrough, NASA astronaut Megan McArthur, ESA astronaut Thomas Pesquet, and JAXA astronaut Akihiko Hoshide. After a 23-hour journey, Crew-2 successfully docked with the International Space Station (ISS) on April 24 at 5:08A ET. Here's everything that happened from launch day to the Crew-2's arrival at the ISS. (Updated April 24, 2021)

Countdown to Launch: NASA and SpaceX Crew-2 Mission

Liftoff set for Friday, April 23, at 5:49A EDT marks the second operational flight of SpaceX’s Crew Dragon. Four space explorers are heading to the International Space Station for a six-month stay. It will take them 23 hours to reach their destination.

NASA Has a New Supersonic Jet and It’s Super-Quiet

There’s more to NASA than space. The agency’s full acronym stands for National Aeronautics and Space Administration. I’ve covered plenty of interesting stories in the space sector, so it’s time to the aeronautics side some love too.

NASA's New Rocket is Taller than the Statue of Liberty

The massive space launch system was unveiled last week. Following successful completion of upcoming simulation tests, NASA will set a date for the first of the Artemis II lunar missions.

This All-Civilian Space Mission Wants to Achieve the Highest Human Orbit Ever

Last year marked a fascinating turning point in the history of spaceflight. For the first time ever, more civilians went into space than professional ones. The private companies Virgin Galactic, Blue Origins, and SpaceX all offer seats for sale, with missions as brief as just a few minutes to as long as a few days.

William Shatner Becomes Oldest Man to Travel to Space After Successful Blue Origin Space Flight

On the morning of October 13, William Shatner joined the crew of New Shepard for its second crewed flight, NS-18. Due to a few holds, the scheduled 10A liftoff was delayed by about 50 minutes from Blue Origin's Launch Site One in Texas. Despite the delays, liftoff and touchdown went off without a hitch, making Star Trek star William Shatner the oldest man to go to space.

Richard Branson of Virgin Galactic Successfully Travels to Space

On Sunday, July 11, around 11:30A ET, Richard Branson, the founder of Virgin Galactic, soared to the edge of space as a passenger aboard Virgin Galactic’s VSS Unity. The space plane then landed safely at Spaceport America in New Mexico, making Branson's space tourism dream come true.

What You Need to Know About Blue Origin’s Launch into Space with Billionaire Jeff Bezos

The countdown has begun for Blue Origin’s first crewed spaceflight. On Tuesday, July 20, 2021, at 9:00A ET, Jeff Bezos and three crewmates are lifting off into space from Blue Origin’s Launch Site near Van Horn, Texas. Watch SPACE LAUNCH LIVE: BLUE ORIGIN & JEFF BEZOS GO TO SPACE on Discovery and Science Channels at 8:00A ET or at

What to Know About NASA’s Boeing Orbital Flight Test-2

The second uncrewed test flight of Boeing’s CST-100 Starliner has been delayed.

Related To: