ORLANDO, Fla. — More than 40 members of Congress from California have asked the White House to reverse cuts NASA has imposed on the Mars Sample Return (MSR) program, warning of job losses and a “decade of lost science.”

The Feb. 1 letter to Shalanda Young, director of the White House’s Office of Management and Budget, marks an escalation of an earlier request by many of the same members in November to NASA Administrator Bill Nelson to undo a slowdown in spending in MSR prompted by uncertainty in fiscal year 2024 appropriations.

The letter was led by Reps. Judy Chu (D-Calif.) and Adam Schiff (D-Calif.) and Sen. Alex Padilla (D-Calif.), with 41 other members of California’s congressional delegation signing it. The lead center for MSR, the Jet Propulsion Laboratory, is in California.

NASA officials said in November that it would “start ramping back on activities” related to MSR because of differences in spending bills. A House appropriations bill offers the agency’s full request of $949.3 million for MSR, but its Senate counterpart includes only $300 million.

NASA, like the rest of the federal government, is operating under a continuing resolution (CR) that funds the agency at 2023 levels, which for MSR is $822.3 million. NASA said the reduction in MSR spending was necessary because of concerns that, if the Senate bill is enacted, MSR could run out of 2024 funding if it spent at the higher 2023 rate for several months.

In the letter, the members of Congress rejected that argument. “This short-sighted and misguided decision will cost hundreds of jobs and a decade of lost science, and it flies in the face of Congressional authority,” they wrote.

Congress has yet to finalize a full-year 2024 spending package, but have made progress in recent weeks, such as providing allocations to the 12 appropriations subcommittees so they know how much money is available to them. The CR that funds NASA runs through March 8.

The letter hints at progress on resolving the difference between the House and Senate funding levels for MSR. “While we are extremely concerned that the Senate appropriations bill for Commerce, Justice, and Science has proposed just $300 million for the program in FY2024, House Appropriations Committee leadership continue to work closely with their colleagues in the Senate on a compromise position,” it states.

If the current reductions are not reversed, the letter warns, “this decision would ensure that JPL will not be able to meet the next launch window and will force the cancellation of billions of dollars in contracts as well as the termination of hundreds of highly skilled employees.”

The reductions have already had effects at JPL. The center laid off 100 contractors in early January, most of whom were involved on MSR. JPL cited uncertainty about the budget for 2024 as a key reason for the layoffs and other cost-cutting efforts.

“We got direction from NASA to plan for the lower level and we’re doing that systematically,” Laurie Leshin, director of JPL, said in a Jan. 8 interview. “So, the first thing to happen is to look at where we’re using on-site contractors on MSR, but other places as well, where JPLers could backfill for that.” Those layoffs could extend to full-time staff, she added, if MSR funding ended up closer to the figure in the Senate bill.

An added degree of uncertainty is the ongoing agency reassessment of the overall MSR architecture, prompted by an independent review that found the current approach to MSR is behind schedule and over budget. That effort is scheduled to be complete in March.

“It is our understanding that the modified mission architecture would simplify the program and reduce annual costs, thereby addressing the concerns expressed about MSR in the FY2024 Senate appropriations bill,” the letter states. NASA has not disclosed publicly any details about any potential alternative mission architectures.

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...