THE PENTAGON — The U.S. Air Force’s $154.3 billion fiscal 2013 budget request — roughly $12 billion less than the service requested in 2012 — includes termination of two aircraft efforts aimed at building partnerships with allies, as well as a new missile outlined for use in stealthy aircraft.

The new NASA budget request pulls the plug on two long-planned joint missions to Mars with the European Space Agency, but agency managers say they are already in touch with their ESA counterparts about a smaller-scale Mars mission in the 2018 planetary launch window.

After two launch failures with Orbital Sciences Corp.’s Taurus XL solid-fuel rocket, NASA has decided to try to launch its replacement Orbiting Carbon Observatory (OCO-2) on another vehicle. The agency and the company signed a bilateral contract modification Feb. 2 that will terminate Orbital’s task order to loft OCO-2 under its NASA Launch Services II (NLS-II) contract. An agency spokesman said the action does not end Orbital’s NLS-II contract, which provides NASA with different launch options under a “catalogue” approach.

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 Feb. 10, 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.

PARIS — A joint European-Russian proposal that assumes no NASA participation in ExoMars has been submitted to the directors of the European Space Agency and the Russian space agency Roscosmos ahead of a Feb. 15 meeting of ESA leaders.

Proponents of civil space exploration are likely to be disappointed by the details of the NASA fiscal 2013 budget plan to be released Feb. 13, particularly when it comes to Mars. It is already known from previous plans that NASA’s overall budget will be flat and tight, with no major new initiates and a lot of backfill from previous spending shortfalls.

NASA’s Technology Demonstration Missions Program is looking for “green” alternatives to toxic hydrazine as a storable propellant for spacecraft, offering contracts worth as much as $50 million each to researchers with promising ideas.

The U.S. Transportation Department wants to develop new spectrum interference standards to protect GPS signals from transmissions in adjacent bands as the battle between broadband-wireless hopeful LightSquared and the GPS industry enters a new phase.