NASA will delay deep-space missions and slash other program spending to offset a $500 million shortfall over five years caused by problems with a once-heralded contract to combine and privatize space operations. The contract combines all data collection and communications that support satellites, probes to other planets and human spaceflight. Written in 1998, the Consolidated Space Operations Contract was supposed to save NASA $1.4 billion over 10 years. But the projected savings were based on poor assumptions and overly ambitious plans, NASA managers now acknowledge. The savings didn’t materialize. Making matters worse, NASA leaders spent money they thought they had saved on satellites that added to the contract’s cost. As a result, all missions to Mars scheduled after 2007 may be pushed back.