NASA will take only an $89 million cut in its topline spending request for fiscal 2013 compared to this year’s operating plan, sources said Friday, but the $17.711 billion NASA budget proposal due out Feb. 13 will axe the joint effort with Europe to return samples from Mars, to pay for development overruns on the James Webb Space Telescope.

Human-spaceflight budgeting continues pretty much as expected, with an $830 million request for commercial crew development (CCDev) work and only a slight drop in the $2.8 billion NASA is spending this year on its heavy-lift Space Launch System (SLS) and Orion multipurpose crew vehicle.

The SLS would get another $1.8 billion under the new request, which must clear an election-year Congress focused on deficit reduction. The exploration-vehicle figures track with last year’s budget runout for fiscal 2013, with the Orion budget tweaked downward to keep it in pace with launch vehicle work.

NASA is “metering” spending on the congressionally mandated deep-space human vehicles to stay within the flat budget, and apparently has decided not to try to recover the deep congressional cut in CCDev work this year. For fiscal 2012, the agency sought $850 million and got $406 million, which set back its target for operational commercial crew flights to the International Space Station (ISS) from 2016 until 2017.

The ISS itself would get another $3 billion under the fiscal 2013 request, roughly as planned to sustain a six-person crew there.

As was the case in its fiscal 2012 request, NASA will seek more funding for its open-ended effort to advance the readiness of a wide range of enabling technologies for space exploration than it will for the “first A in NASA”: aeronautics. Space technology would get $699 million in the new request, while aeronautics drops to $500 million.

The budget cuts $300 million from planetary science, and kills the joint effort with the European Space Agency to explore Mars robotically in preparation for a sample-return mission. Europe has already prepared a bilateral Mars-exploration plan with the Russian space agency Roscosmos, after NASA withdrew from three-way talks in December (AWIN First, Feb. 10).

That leaves only the Mars Science Laboratory mission now en route to Mars, and the Mars Atmosphere and Volatile Evolution mission in 2013 on NASA’s plate for robotic exploration of the red planet. The cut apparently was made to cover serious overruns in the James Webb Space Telescope development effort.

In its operating plan for fiscal 2011, NASA had $18.448 billion to spend, so there is a downward trend in its topline. But in general, federal research agencies like NASA and, reportedly, the National Science Foundation, suffered only minor hits to their long-range budget planning.