Delays launching the shuttle Columbia and repeated tests to track down the source of elusive hydrogen leaks have cost NASA more than $3 million in lost fuel, overtime and travel expenses alone.

But agency officials said Wednesday the cost is minuscule compared to the overall price of a shuttle launch - more than $300 million - and the need to make absolutely sure no dangerous leaks are present at launch that could endanger a shuttle or its crew.NASA originally intended to launch eight shuttle missions in fiscal year 1990. The agency's budget for space shuttle operations during that period totaled $2.5 billion, which works out to roughly $311 million per flight.