New York (CNN Business) After more than a week of speculation, SpaceX confirmed that its Crew Dragon spacecraft was "destroyed" during a recent test fire .

That could seriously derail the company's plans to begin flying astronauts to the International Space Station this year.

Crew Dragon had a great start to 2019, and it executed an uncrewed demo flight in March during which it docked with the space station and returned safely home. But on April 20, the spacecraft was undergoing a "series of engine tests" at a facility in Cape Canaveral when something went wrong during the final stretch.

Thick plumes of smoke rose into the Florida sky, sparking concern that there had been some kind of explosion linked to a serious issue. But at the time, SpaceX only confirmed that an "anomaly" occurred.

NASA and SpaceX received heightened scrutiny after what appeared to be footage of the test leaked online. It showed the spacecraft erupting in flames. The Orlando Sentinel reported earlier this week that internal NASA memos obtained by the outlet confirmed the footage was authentic.

For the first time since the incident, SpaceX on Thursday shared a more detailed account of what happened.

The Crew Dragon spacecraft was destroyed, said Hans Koenigsmann, SpaceX's vice president of mission assurance, during a press briefing about a separate SpaceX mission.

He said the event was linked to the firing up of Crew Dragon's SuperDraco engines, which power the spacecraft's emergency escape system.

If something goes wrong during launch, for example, the SuperDraco engines can propel the capsule away from a malfunctioning rocket and get the crew to safety. A demonstration of the safety abort system had been scheduled for June.

Koenigsmann said it's still possible to get SpaceX's schedule back on track for Crew Dragon to launch people this year, but he admitted that the mishap was "certainly not great news for the schedule overall."

He added that the investigation into the engine issue is still underway. And he noted that other Crew Dragon spacecrafts were already under construction, so the company won't be starting from square one.

Crew Dragon is already overdue, but NASA had wanted the capsule to begin flying US astronauts later this year.

The United States has not had the technology to fly humans to orbit since the space shuttle program ended in 2011. Meanwhile, NASA has paid Russia about $80 million per seat to send astronauts to the International Space Station aboard Soyuz capsules — a fact that isn't very popular in the halls of Congress.

NASA decided to ask the private sector to design and build a new generation of spacecrafts.

Boeing, BA SpaceX andwhich is building a vehicle called Starliner, were awarded contracts worth up to $2.6 billion and $4.2 billion, respectively, in 2014. Both capsules were supposed to start flying in 2017, but they have been hampered by delays.

SpaceX, which was founded by Elon Musk in 2002, beat Boeing to the launch pad by sending Crew Dragon on an uncrewed test flight in March, during which the capsule docked with the ISS for a few days before returning home. That mission appeared to go off without a hitch.

Crew Dragon was scheduled to conduct a key test of its emergency abort system in June. And its first crewed mission, which will carry astronauts Doug Hurley and Bob Behnken, was slated for July, though NASA recently said that timeline was under review.

Boeing is aiming to launch Starliner's uncrewed test flight sometime in August, potentially putting the capsule on track to fly astronauts by the end of the year.