In the first NASA budget of the post-space shuttle era, a congressional deal will fund the agency’s top priorities, including a next-generation space telescope, a new giant rocket and a deep-space capsule to carry astronauts far beyond Earth.

In return, however, the quest to ferry astronauts to the international space station aboard American-built spacecraft took a budget hit that may delay launch of the vehicles beyond 2016, the target date proposed by NASA.

Senate and House negotiators reached the deal late Monday after two weeks of hammering out a “minibus” appropriations bill to fund the nation’s science agencies and keep the government operating past Nov. 18. The two chambers are expected to approve the bill by the end of the week.

With a national budget crunch underway, NASA presented an attractive target for House Republicans. The House had voted to provide $16.8 billion for NASA, while the Senate had sought $17.9 billion. Monday’s deal provides $17.8 billion for the agency, some $650 million less than last year and $924 million less than President Obama had requested in February.

The deal resolves a budget fight that erupted this summer over the skyrocketing costs of the James Webb Space Telescope, NASA’s successor to the Hubble Space Telescope. In July, NASA’s chief purse-string holder in the House, Rep. Frank Wolf (R-Va.)zeroed out funding for the project, which NASA now says will cost $8.8 billion to build and operate.

But the telescope’s champion in the Senate, Barbara A. Mikulski (D-Md.), succeeded in restoring the funding, and the agreement will fund the telescope in fiscal year 2012. The bill caps total development costs at $8 billion and holds a NASA manager directly accountable for any further cost overruns.

“I wanted to make sure we were getting a handle on the Webb,” Wolf said Tuesday. “I never wanted to kill it.”

Debra Elmesgreen, president of the American Astronomical Society, is a key advocate for the telescope, slated for launch in 2018. “For this year, it looks like everything is on track,” she said. “This is exactly what we wanted.”

The telescope will receive a total of $529 million in 2012, $375 million more than NASA had originally projected for that year. The additional amount will be paid for via “commensurate reductions in other programs,” according to the congressional budget report released late Monday. Although the bill does not pinpoint which NASA programs will be cut, scientists planning robotic missions to Mars and other planets worry their programs will be squeezed.

Meanwhile, NASA’s plans to eventually send astronauts far beyond Earth received more than $3 billion. The budget provides $1.9 billion to develop a giant rocket called the Space Launch System and $1.2 billion for the Orion crew capsule. Last week, NASA announced an Orion test launch in 2014, but the big new rocket won’t fly until at least 2017.

Senate supporters ensured that the Space Launch System, which heavily relies on Gulf Coast factories that built the space shuttle, received full funding.

“This budget makes a major investment in the next generation of human space flight,” said Sen. Bill Nelson (D-Fla.) in a statement. Nelson and Kay Bailey Hutchison (R-Tex.) pressed House colleagues to support the rocket.

But their prize comes at a price: A likely delay in flights of American spacecraft to the space station. Obama asked for $850 million in fiscal year 2012 for NASA’s “commercial crew” initiative, which in April doled out $270 million to four American companies to develop rockets, capsules and space planes to ferry astronauts to the space station. Instead, NASA will get $406 million.

“We have a very, very tight budget,” Wolf said. “Everything is a compromise.”

The reduced funding will most likely push the launch of American-built space taxis beyond the 2016 target date, said William Gerstenmaier, the agency’s associate administrator for human exploration and operations, during House testimony Oct. 26.

Such a delay will cost the agency $480 million per year beyond 2016, Gerstenmaier added. That’s because the agency buys rides on Russian Soyuz vehicles, which cost $63 million per seat. The current NASA-Russian deal expires in 2016.

Early Monday, American astronaut Daniel Burbank and two Russians rocketed toward the space station aboard a Soyuz, marking the first human trip into space since the final space shuttle mission ended in July.