NASA’s new heavy-lift rocket will not get off the ground until December 2019 at the earliest, and its maiden flight could easily slip to the middle of 2020, the space agency announced on Wednesday.
The rocket known as the Space Launch System would succeed the Saturn 5 that took astronauts to the moon more than four decades ago. NASA says it plans to use the vehicle to take astronauts not only to the moon — one of the goals of the Trump administration — but someday Mars.
Earlier this year, NASA acknowledged it would not be able to make the previously announced launch date of November 2018 for the first flight, which will not carry any astronauts.
The completed review indicates a launch date of June 2020, but NASA said it might be possible to move up the launch date by six months.
“This earlier launch date is reasonable and challenges the teams to stay focused on tasks without creating undue pressure,” William H. Gerstenmaier, NASA’s associate administrator for human exploration and operations, said at a hearing of the House space subcommittee on Thursday. “Furthermore, NASA is taking additional steps to reduce schedule risks for both known and unknown issues and protect for the earliest possible launch date.”
At the request of the Trump administration, NASA examined the possibility of putting astronauts aboard the rocket’s first flight. But that would have further pushed back the launch date and added as much as $900 million to the program’s price tag. NASA and the administration decided to stick with the original plan.
A crewless flight also allows more thorough testing, closer to the edge of the capabilities of the Orion capsule, the separate spacecraft carried by the rocket where astronauts will eventually be seated.
Mr. Gerstenmaier told Congress that the additional delay for the first flight adds less than 15 percent to the cost of the rocket and slightly more than that for ground systems.
The delays have been caused in part by technological hiccups as well as factors out of NASA’s control, like a tornado striking the Michoud Assembly Facility in Louisiana, where parts of the rocket are being built, in February.
He said that NASA is still on track for the first flight with astronauts in 2023. The rocket could also be used in the early 2020s to propel a robotic probe to study Jupiter to study Europa, a moon with a vast ocean under its icy crust that is thought to be one of the most promising places in the solar system to look for life.
Mr. Gerstenmaier said the agency would soon a provide a framework of NASA’s plans beyond 2023.
A report this week from NASA’s inspector general highlighted problems that the program still faces including very tight budget reserves.
NASA also remains without a permanent leader since Charles F. Bolden Jr. stepped down as administrator on President Trump’s Inauguration Day. The 293 days that have passed since are the longest that NASA has been without a permanent administrator.
On Wednesday, the nomination of Jim Bridenstine, an Oklahoma congressman, to be the next administrator narrowly won approval of a key Senate panel, with all 14 Republicans on the commerce, science and transportation committee voting in favor and all 13 Democrats opposed. Bill Nelson, a Democratic senator from Florida, said Mr. Bridenstine lacked the experience needed for running a large agency like NASA. He also criticized Mr. Bridenstine for past statements questioning climate change. The full Senate still needs to vote on the nomination.
Some outside space experts have suggested that NASA should abandon the Space Launch System and turn to alternatives being developed by commercial companies like SpaceX and Blue Origin that would be cheaper. SpaceX is aiming for the first launch of its Falcon Heavy rocket within the next few months, but that rocket is not as powerful as the Space Launch System and is also years behind schedule.
Mr. Bridenstine has been an advocate of commercial space companies but also supports the Space Launch System and Orion.
At Thursday’s hearing, Lamar Smith, the Texas Republican who chairs the House Committee on Science, Space and Technology, expressed frustration over the continuing delays and cost overruns. “The more setbacks S.L.S. and Orion face, the more support builds for other options,” he said.
Mr. Smith, however, will not be among those deciding the future of NASA. He announced last week that he would retire when his term ends in January 2019.