SpaceX suffered a setback in preparations for its first crewed launch to the International Space Station today when one of its Crew Dragon spacecraft experienced an anomaly during an engine test firing in Florida.

No injuries were reported, but the anomaly threw up a huge pillar of smoke from SpaceX’s Landing Zone 1 during testing of the Dragon’s Super Draco thrusters. The static-fire test was being conducted in preparation for an in-flight abort test.

The in-flight abort test is meant to demonstrate the Crew Dragon’s system for rocketing the crew to a safe landing in the event of an emergency experienced in the early stages of flight. The uncrewed abort test is a necessary step toward sending astronauts to the space station on a different Crew Dragon by as early as July.

Today’s anomaly seems likely to force a change in that schedule.

Here’s what SpaceX had to say in an emailed statement:

“Earlier today, SpaceX conducted a series of engine tests on a Crew Dragon test vehicle on our test stand at Landing Zone 1 at Cape Canaveral, Florida. The initial tests completed successfully but the final test resulted in an anomaly on the test stand. “Ensuring that our systems meet rigorous safety standards and detecting anomalies like this prior to flight are the main reasons why we test. Our teams are investigating and working closely with our NASA partners.”

SpaceX did not immediately provide further details about the anomaly — for example, whether the Crew Dragon being tested today was the spacecraft slated for use in the in-flight abort test, or whether the craft was seriously damaged.

Other reports, however, suggest that the test article was the Crew Dragon that flew a successful uncrewed mission to the space station and back last month. That Dragon was slated to be reused for the upcoming in-flight abort test. Several reports, including what appears to be a tweeted video of the anomalous event, indicate that the Dragon was blown apart.

In a tweeted statement, NASA Administrator Jim Bridenstine said the space agency and SpaceX were assessing the anomaly and working together to ensure that astronauts will be flown safely when the time comes:

NASA has been notified about the results of the @SpaceX Static Fire Test and the anomaly that occurred during the final test. We will work closely to ensure we safely move forward with our Commercial Crew Program. pic.twitter.com/yE2J5yGzA7 — Jim Bridenstine (@JimBridenstine) April 21, 2019

SpaceX conducted a successful pad abort test of the Crew Dragon in 2015.

NASA is providing billions of dollars to support the development of the Crew Dragon — an upgraded version of the robotic cargo capsule that has been delivering supplies to the space station since 2012 — as well as Boeing’s CST-100 Starliner space taxi.

Boeing’s Starliner development effort suffered a setback last June when an anomaly cropped up during a test of the spacecraft’s launch abort engine system. NASA’s latest schedule calls for the Starliner to make an uncrewed flight to the space station no earlier than August, with a crewed demonstration flight to follow no earlier than late 2019.