WASHINGTON — NASA is suspending payments on a nearly $70 million contract with Orbital Sciences Corp. for launch of the Orbiting Carbon Observatory (OCO)-2 environmental satellite aboard a Taurus XL rocket, which failed in its last two missions.

Dulles, Va.-based Orbital remains under contract to build OCO-2, a duplicate of the $200 million carbon-mapping satellite destroyed in a 2009 Taurus XL launch failure blamed on payload-fairing separation error. However, the $68.1 million NASA had budgeted for a February 2013 Taurus XL launch of OCO-2 has been “temporarily put on hold” as the agency evaluates “launch services options for the OCO-2 mission,” according to NASA’s 2011 initial operating plan.

A copy of the spending plan, delivered to Capitol Hill June 15, was obtained by Space News.

NASA awarded Orbital the OCO-2 launch contract in 2010. But after losing a second climate-observing craft — the $424 million Glory satellite — in a Taurus XL launch failure in March, NASA’s Earth science chief said he would be unwilling to put another satellite on the rocket until it proves itself in flight. The more recent failure also was blamed on a fairing separation issue.

“I would go more than recertified, personally,” Michael Freilich, director of NASA’s Earth Science Division, told Space News in May. “I would go demonstrated.”

NASA expects OCO-2’s launch to be delayed, and the satellite’s development cost to rise, as a result of its decision to look for a different rocket.

In the near term, losing Glory is expected to save NASA about $9 million that would have been spent this year on mission operations.

But those savings are more than offset by $125 million in previously unanticipated funding NASA intends to spread across nearly a dozen science missions nearing launch, according to the June 15 operating plan. The largest chunk of that money — about $37 million — would go to the NPOESS Preparatory Project, a nearly $900 million weather- and climate-monitoring satellite due to launch in October.

Among the other missions needing anywhere between $2 million and $11 million extra this year to cover “emerging FY2011 requirements” are the just-launched Aquarius SAC-D mission, the Juno probe launching toward Jupiter in August, the Mars Science Laboratory launching in November, and the Lunar Atmosphere and Dust Environment Explorer launching in 2012.

One major NASA science program that apparently will not be getting additional money this year despite an apparent urgent need is the James Webb Space Telescope. An independent panel told NASA last fall that the $5 billion-plus infrared astronomy mission would need an additional $250 million in 2011 to maintain a newly projected 2015 launch date.

“NASA continues to make progress on the development of the James Webb Space Telescope (JWST) and is completing the JWST replan,” NASA Administrator Charles Bolden said in a letter accompanying the June 15 operating plan. “We may submit an updated FY2011 Operating Plan this summer.”

NASA’s operating plan also includes $1.2 billion for the Multi-Purpose Crew Vehicle and $1.8 billion for the Space Launch System — the same amounts included in the omnibus spending bill President Barack Obama signed into law in April.

Brian Berger is editor in chief of SpaceNews.com and the SpaceNews magazine. He joined SpaceNews.com in 1998, spending his first decade with the publication covering NASA. His reporting on the 2003 Space Shuttle Columbia accident was...