A key source told Ars that the recent budget action in the House and Senate indicates that legislators are taking the impoundment threat from the Office of Management and Budget seriously. Their best weapon in this fight would be to pass a budget on time, and they appear to be trying to do so.

The departures are playing out as NASA and other government agencies contend with significant cuts to funding and personnel.

"Though the House and Senate have much still to debate on full-year appropriations, this much is clear: Congress is rejecting the full extent of the unprecedented, unstrategic, and wasteful cuts to NASA and NASA science proposed by the White House’s Office of Management and Budget," the Planetary Society said in a statement.

It remains an open question as to whether NASA and the U.S. space program will survive the Republican president’s second term.

Current and former NASA employees have co-signed a declaration protesting changes at the agency that some say pose a grave risk to astronauts.

A letter released Monday from more than 150 NASA employees urged agency officials not to make deep budgetary cuts proposed by the White House, saying they would have “dire” consequences. “We are