The bipartisan nature of the amendment, sponsored by Commerce-Justice-Science Appropriations Subcommittee Chairwoman Barbara Mikulski, D-Md., and ranking member Richard Shelby, R-Ala., was underscored by its passage without a roll-call vote.
Backers said it was necessary to begin the process of returning the Space Shuttle to flight, and avoid lagging behind other nations' space exploration capabilities.
"We didn't cut NASA's budget after the Challenger [explosion]; we shouldn't do it after the Columbia," Mikulski said.
The amendment brings the price tag of emergency funds, which do not count against budget caps, to nearly $5 billion added to spending bills by senators in the last few days. The Senate added almost $4 billion in border-security related funds to the Pentagon budget bill this week.
Both bills are tied up in the larger budget stalemate between President Bush and Congress, however, with Democrats proposing $23 billion more than he requested.
Bush threatened to veto the Commerce-Justice-Science measure even before the NASA funds were added, as Democrats included $3.2 billion above his budget request for local police forces, the FBI, ocean research, economic development and other programs.
He is expected to sign the Defense bill, making it an attractive option to hold back as a vehicle to carry domestic measures Bush opposes.
Border-security funds are also included in the Homeland Security spending bill, which could be removed from that measure.
Republicans shifted the money to the Defense bill in order to allow Bush to safely veto the homeland measure, which even without the border funds is $2.2 billion above his request.
Democrats could also choose to keep the money in the homeland bill, although the addition of the border funds to the Defense bill might make that measure an even more attractive target for Democrats seeking leverage on their domestic priorities.
On that front, Republicans turned up the heat on Democrats for delaying final action on a $109 billion bill funding military facilities and veterans' benefits, which received near-unanimous support in both chambers.
"Our veterans deserve better. Funding for these critical programs should not be held hostage in an effort to promote a political agenda," Office of Management and Budget Director Jim Nussle wrote in a letter Thursday to leaders of the House and Senate Appropriations committees.
Final passage of the Commerce-Justice-Science bill will come soon after the Senate reconvenes Oct. 15.
Afterward, the Senate plans to consider a $150 billion Labor-Health and Human Services measure, which erases $3.6 billion in cuts proposed by Bush for a total of $9 billion above his request.
Initial preparations are already under way to send those bills to Bush as free-standing measures. But this year's legislative "endgame" remains in doubt, as House Republicans have sewn up the necessary votes to sustain Bush's promised vetoes.
Democrats still have a few cards they can play. For example, Bush wants his signature No Child Left Behind law reauthorized, but House Education and Labor Chairman George Miller, D-Calif., said the president will "have a big problem getting that bill" unless he agrees to more education funding.
Meanwhile, Democrats argue they can use Bush's opposition to their own political advantage while putting pressure on moderate Republicans facing re-election fights next year, a point some in the GOP do not dispute.
"I don't know who's advising him up there, but the president is really out of touch," said House Energy and Water Appropriations Subcommittee ranking member David Hobson, R-Ohio. "It's too little, too late for him to be a fiscal conservative. He should have vetoed the  farm bill ... now he's against the SCHIP bill, he wants $190 billion more for the war, but he's picking a fight over $23 billion?"