The rocket and spacecraft NASA plans to use to get astronauts to the moon could cost $50 billion, according to a government watchdog report released Tuesday — far more than the space agency had said it would need to meet a White House mandate to return to the lunar surface by 2024.

The report, by the NASA Inspector General, painted another grim picture of the troubles that have long plagued the Space Launch System rocket as Boeing, NASA’s prime contractor on the rocket, struggles to get the unwieldy program under control. It said that more schedule delays were likely and that the space agency might not be able to meet the goal of landing people on the moon by 2024 or orbiting Mars by the 2030s.

It was the second time in less than a week that Boeing’s work for NASA has been criticized. On Friday, NASA officials said an investigation of the marred test flight of the company’s Starliner spacecraft in December, when the spacecraft was unable to dock with the International Space Station, had identified major problems with Boeing’s testing procedures. Officials said the investigation led to 61 corrective actions and identified 49 gaps in Boeing’s testing procedures. NASA also determined that it would need to embed its own software experts with Boeing’s team to more rigorously oversee its work and testing.

The new IG report blames both NASA’s lax oversight of the program and Boeing’s poor performance for costly delays that would ratchet up the price of NASA’s moon mission. Earlier this year, the White House proposed increasing NASA’s budget significantly, to $25.2 billion for the next fiscal year, with annual increases after that, with a total cost of its moon program, dubbed Artemis, coming to $35 billion.

In response to the report, NASA said the costs in the White House’s budget and those reported by the IG were “unrelated figures”— one the cost of the years long SLS and Orion program; the other the Artemis effort to return to the moon, Doug Loverro, NASA’s associate administrator for human spaceflight, said in a statement to The Post.

The Artemis program costs are only for fiscal years 2021 through 2025, and include only systems such as the landers that would ferry astronauts to the surface of the moon. Its figure doesn’t include the costs NASA has incurred over many years on the SLS rocket and Orion spacecraft, which would be used to fly astronauts to the moon.

"NASA accepts that its management of SLS and Boeing’s performance has been deficient and we are moving to correct these issues,” Loverro said. "But nothing in the report was unexpected, nor does it alter our assessment of NASA’s ability to achieve the goals established by the Administration to land on the Moon by 2024.”

NASA has so far obligated nearly $15 billion for the development of the SLS rocket, which is intended to be the most powerful ever flown. But its first launch, scheduled for November, is likely to slip to spring of 2021, the report said. If that happens, the cost would jump to $18.3 billion, the IG said.

And if the second launch of the SLS slips to 2023, the cost of the program would increase to $22.8 billion, the IG reported.

When you add the costs of the Orion spacecraft and the associated ground systems, the total cost could balloon to $50 billion by 2024, the IG found.

Every major component of the rocket being designed for the first Artemis mission has “experienced technical challenges, performance issues and requirement changes that collectively have resulted in $2 billion in cost overruns and increases and at least two years of schedule delays,” the report said.

In a statement, Boeing defended its work and promised that the delays would pay off in the end.

“In partnership with NASA, Boeing is building the only rocket capable of safely and efficiently delivering humans and necessary hardware back to the moon, and far beyond,” the statement said. “Such an undertaking has certainly had its cost and schedule challenges over the years, but the investment has paid off in bringing together the required talent, technology and tooling to build this unprecedented deep space rocket.”

The company said it was making progress, delivering the first rocket core stage to NASA last month. And it said that the “hard-earned experience acquired during initial SLS development is resulting in significant savings and efficiencies in subsequent development and production.”

In an appendix to the report, NASA concurred with each of the IG’s recommendations, including getting better insight into the true costs of the program.

NASA has “significantly increased the workforce” to complete the core stage of the rocket, the IG found. But it said the agency “continues to struggle managing SLS program costs and schedule as the launch date for the first integrated SLS/Orion mission slips further.”

As the rocket enters a key testing phase, there may be additional delays. And the IG said, that “may hinder NASA’s ability to meet the agency’s mid and longer term space exploration goals, including landing on the moon by 2024 and reaching Mars in the 2030s.”

The report comes at a bad time for Boeing, which is still facing the fallout from the grounding last year of its 737 Max aircraft after two planes crashed, killing 346 people.

Meanwhile, NASA said that the investigation into what went wrong with the Starliner spacecraft is continuing.