The NASA Office of the Inspector General (OIG) disagrees with NASA's announcement last week that the next American astronauts will land on the Moon in 2025, a year later than previously planned. According to a new audit released today, it won't be until 2026 at the earliest, and the Artemis program will cost $93 billion through 2025.

"Moreover, while NASA has several initiatives underway aimed at increasing affordability, we project the current production cost of a single SLS/Orion system to be $4.1 billion per launch," the OIG report states.

NASA admitted last week that it will not be able to fulfill the 2024 objective established by President Donald Trump in 2019 and adopted by President Joe Biden earlier this year. A seven-month delay in the creation of a Human Landing System (HLS) to get to and from the lunar surface was a key cause in the delay, as was litigation over the contract NASA awarded to SpaceX.

Current Administrator Bill Nelson stressed that the agency would not have a firm grasp on the timeline until it could meet down with SpaceX for a thorough study, but 2025 is the new tentative target.

Despite the fact that the Artemis program was originally announced in December 2017, work on Orion and the SLS began in 2011. So, the $93 billion projection in the OIG study covers more than a decade of spending, from FY 2012 through FY 2025. (Fiscal years in the U.S. begin on Oct. 1 and end on Sept. 30; FY2012, for example, began on Oct. 1, 2011).

The original plan to return to the moon was envisioned landing astronauts near the moon's south pole for the first time by 2028. In March 2019, however, the Trump administration hastened matters, re-targeting the first crewed lunar landing since the Apollo days for 2024 and calling the endeavor the Artemis program.

That revised schedule was widely seen among the space community as extremely ambitious, and NASA is no longer working toward it: Last week, agency boss Bill Nelson revealed that the first crewed Artemis landing will likely take place no earlier than 2025.

And 2025 is also out of reach. NASA will miss the Trump administration's late-2024 landing goal "by several years," according to the new OIG report, which cites the need to develop and test new Artemis spacesuits, which are behind schedule, as well as the program's HLS, which will ferry astronauts to and from the lunar surface.

For comparison, the U.S. spent $28 billion on NASA's Apollo moon program between 1960 and 1973, according to the nonprofit Planetary Society. In today's dollars, that's around $280 billion.

Artemis' high cost is due in part to the fact that, except for the Orion capsule, subsystems, and launch facilities, "all components are expendable and 'single use,' unlike emerging commercial space flight systems," the Inspector General said.