In a dramatic cost-cutting measure, the Jet Propulsion Laboratory in Pasadena, California, will lay off 530 people, about 8 percent of lab staffing.

JPL Director Laurie Leshin informed workers Feb. 6, saying in a memo that the cuts “are among the most challenging that we have had to make.”

Ms. Leshin told most employees to work from home Wednesday “so everyone can be in a safe, comfortable environment on a stressful day.”

JPL said the cuts were necessary “to adjust to a lower budget from NASA, and in the absence of a 2024 appropriation from Congress,” according to the memo, which was posted on the JPL website.

The layoffs will also affect 40 contractors and follow last month’s dismissal of 100 contractors, many of whom were working on the Mars Sample Return, a major project for the Pasadena lab, according to spacenews.com, a publication that covers the space and satellite industries.

NASA has reduced spending on the Mars project because Congress’ willingness to fund it is uncertain, SpaceNews reported. While the House spending bill allots $949 million to the project, the Senate would give it just $300 million, prompting NASA to cut back in case the lower level is enacted.

In a statement, Ms. Leshin said the $300 million figure would be a 63 percent decrease from the fiscal 2022-23 level.

The Mars Sample Return’s mission, as described on mars.nasa.gov, is to fetch Mars materials collected by the Perseverance rover and deliver them to Earth. Launch is planned for 2027 with a return to Earth in 2033.

The mission involves a lander carrying a small rocket that would set down near Mars’ Jezero Crater. Perseverance would load the rocket with samples, and the rocket would carry them to Mars orbit, where they would be captured by another spacecraft and brought back to Earth.

JPL’s cost cutting drew some pushback from Democratic Rep. Judy Chu, whose district includes Pasadena. In a statement, she called the move “premature and misguided.”

“I’m hopeful in the coming weeks we can work to broker a deal with the Administration and Congress to restore funding to the levels necessary to rehire workers and promote the kinds of scientific discovery @NASAJPL has been on the frontlines of for decades,” she said in a post on X, formerly Twitter.

U.S. Senate candidate Rep. Adam Schiff, whose district also includes Pasadena, also opposed the cuts, calling them “a devastating blow to the talented men and women working on the Mars Sample Return mission.”