It's hardly the most opportune time to announce a huge cost overrun for a major science facility. But last week NASA told Congress that its proposed successor to Hubble, the 6.5-meter James Webb Space Telescope (JWST), will require an additional $1.5 billion and another delay.
NASA delivered the bad budget news--first reported this week by the BBC and Nature—on 16 August, says space agency spokesperson Trent Perrotto. Two outside sources say the silver lining for astronomers is that NASA hopes to share the fiscal burden equally between astrophysics and other branches of the $18-billion agency rather than pummeling its science programs.
The new $8 billion price tag doesn't include operating costs of about $780 million for the far-seeing infrared observatory's first 5 years in space. Under the revised NASA plan, Webb would not only cost 23% more but would launch in the fall of 2018, 2 years later than the date the agency had suggested only months ago.
NASA is withholding details of its new cost estimates because the so-called "replan" is under review by the White House Office of Management and Budget (OMB). Those details may not be available until the president submits his 2013 budget request to Congress in February. But leaders in the astronomy community are hoping that the White House will endorse both the higher number and the cost-sharing plan. "To damage science for such a small contribution from the rest of the agency would not be very responsible," says astronomer and Webb proponent Garth Illingworth of the University of California, Santa Cruz.
Last year, Illingworth was part of an independent panel convened by Senator Barbara Mikulski (D-MD), who chairs a spending subcommittee that controls NASA's budget, to investigate why the Webb mission was continually exceeding its budget. The panel, led by John Casani of NASA's Jet Propulsion Laboratory in Pasadena, California, found that the project was mismanaged and chronically underfunded. Construction delays translated into higher costs when work that was supposed to be completed in one year got deferred to the next.
In November 2010, the Casani panel estimated that Webb, which is designed to plumb the depths of space to image the first galaxies, would cost a minimum of $6.2 billion to $6.8 billion if launched in 2015. (In 2008 the estimated cost was $5.1 billion, with a 2014 launch). But the immediate infusion of money the panel said would be needed to launch Webb in 2015 never happened.
Last month, Webb program director Richard Howard of NASA presented a revised plan to an astrophysics advisory committee at NASA headquarters. His presentation assumed a launch in 2018 but did not include the new cost estimate.
The larger price tag is due to the additional costs of maintaining the army of scientists and engineers working on the project, according to Illingworth and another Webb cheerleader, cosmologist Michael Turner of the University of Chicago, who has an editorial supporting the mission  in this week's issue of Science. It also includes higher-than-usual reserves to accommodate unforeseen problems that might emerge during final construction of the telescope, says Illingworth.
NASA and OMB are being extra cautious in their estimates because this may be the last chance to save Webb, says Matt Mountain of the Space Telescope Science Institute in Baltimore, Maryland. The institute oversees Hubble and would play a similar role for Webb. Illingworth says he's hoping the final cost of the project might be reduced slightly and that launch might be advanced by 6 months.
"Every extra penny will make it harder to get funded in the current budgetary climate," notes Turner. "The lack of transparency by NASA doesn't help either, but we have to do this or lose credibility as a leader in both science and space and as a reliable international partner," he says.
NASA says it will have spent $3.5 billion on Webb by the end of September. NASA astrophysics advisory subcommittee chair Alan Boss of the Carnegie Institute for Science in Washington, D.C., worries that the higher overall price will make it easier for Congress to pull the plug. "That weakens the argument that NASA has too much already invested in JWST to drop it," he says.
Last month, the House of Representatives Appropriations Committee approved a spending bill that would eliminate funding for the Webb telescope. The next major spending milestone is expected to occur when Mikulski's committee marks up NASA's 2012 budget. Mikulski has so far been a vocal and steadfast Webb supporter. But advocates fear that the latest cost estimate could undermine that support.