WASHINGTON (AFP) - After a series of delays and billions spent over budget, the potent James Webb Space Telescope is on track to launch in 2018 at a total project cost of $8.8 billion, Nasa vowed on Tuesday. The project, which aims to build the worlds most powerful telescope, 100 times more sensitive than the Hubble space telescope, has been riddled by poor management and cost overruns. Though a Congressional subcommittee threatened to ax the project altogether earlier this year as lawmakers grappled with how to reduce a more than $15 trillion national deficit, Congress has since agreed to fully fund it at the level Nasa requested. But NASAs new JWST program manager Rick Howard who came on board last year, still faced an acrimonious grilling on Tuesday from lawmakers in the House Committee on Science, Space and Technology. Committee chair Ralph Hall described the project as another case study of Nasa mismanagement and said the NASA reshuffle was the agencys last opportunity to hold this program together.