Updated 10 a.m. Eastern Oct. 5.

BREMEN, Germany — A day after a SpaceX executive expressed doubts that his company would be able to carry out its first commercial crew test flight before the end of the year, NASA issued an updated schedule that delayed that mission to 2019.

In an Oct. 4 statement, NASA said the revised date for the uncrewed test flight of SpaceX’s Crew Dragon spacecraft was now January 2019. The vehicle could be ready for launch in December, the agency added, but scheduled it for January “to accommodate docking opportunities at the orbiting laboratory.”

The announcement came a day after Hans Koenigsmann, vice president of build and flight reliability for SpaceX, said in a speech at the 69th International Astronautical Congress here that he had doubts that the mission, previously scheduled for November, would launch before the end of the year.

“We’re working hard to get this done this year,” he said. “The hardware might be ready, but we might still have to do some paperwork on the certification side of it. It’s going to be a close call whether we fly this year or not.”

The new schedule also rescheduled the crewed flight test, carrying NASA astronauts Bob Behnken and Doug Hurley, for June 2019. That launch was scheduled for April in the previous schedule released in August, although SpaceX Chief Executive Elon Musk, in a Sept. 17 presentation, said he expected the mission to fly “hopefully in the second quarter of next year.”

“Having completed a number of additional milestones including substantial training and numerous integrated mission simulations, end-to-end Dragon checkouts at the Cape, complete Falcon 9 vehicle integration review, and installation of the crew access arm at LC-39A, SpaceX is on track for launch readiness in December,” said SpaceX spokesperson Eva Behrend in a statement to SpaceNews. “We look forward to launching our first demonstration flight of Crew Dragon-one of the safest, most-advanced human spaceflight systems ever built-as part of the Commercial Crew program and working with NASA to identify the specific launch target date soon.”

NASA also revised the schedule for Boeing’s two test flights of its CST-100 Starliner. An uncrewed test flight, originally scheduled for late 2018 or early 2019, is now planned for March 2019. The crewed test flight previously scheduled for mid-2019 is now scheduled for August 2019.

That crewed test flight will carry NASA astronauts Eric Boe and Nicole Aunapu Mann along with Chris Ferguson, a Boeing test pilot and former NASA astronaut. In an Oct. 2 briefing here, Ferguson, who is also crew and mission operations director for the Starliner program at Boeing, said that earlier schedule is “exactly where we are” but deferred questions on when more precise launch dates would be released.

If the companies maintain the new schedule and successfully carry out their test flights, NASA said it expects to be ready to carry the first operational commercial crew mission in August 2019, with the second to follow in December 2019.

NASA, in its statement about the new schedule, said it would provide more frequent updates on launch schedules as the two companies inch closer to their test flights. Future updates will be released approximately monthly.

“As we get closer to launching human spacecraft from the U.S., we can be more precise in our schedules,” said Phil McAlister, director of Commercial Spaceflight Development at NASA Headquarters, in the statement. “This allows our technical teams to work efficiently toward the most up-to-date schedules, while allowing us to provide regular updates publicly on the progress of our commercial crew partners.”

He acknowledged that those updates could include additional delays. “These are new spacecraft, and the engineering teams have a lot of work to do before the systems will be ready to fly.”