In the blur of astro-news from last week — the deaths of two prominent astronomers, fabulous Comet Hartley 2 results, asteroid dust inside Hayabusa, and a planet from another galaxy — we couldn't quite get to an important story involving Hubble's eventual replacement: the James Webb Space Telescope.The JWST effort has been under way in earnest since 2002, when NASA managers selected TRW as the project's prime contractor and renamed the spacecraft (formerly the Next Generation Space Telescope) to honor James E. Webb, the agency's second administrator. The plan was, and is, to place a giant space observatory far from Earth (to minimize interference) and give it a primary mirror 21 feet (6.5 m) across — more than seven times Hubble's light grasp — to probe the visible and (especially) infrared universe as never before.
Back then, rosy announcements predicted a total cost of around $1 billion and a launch sometime this year.
If only! Along the way, reality set in. By 2005 the construction cost-to-launch estimate had ballooned to $2.4 billion, and the debut had slipped to 2014. That's where things stood until this year, when an Independent Comprehensive Review Panel took a hard look at the numbers. The bottom line is that JWST's total cost to launch and operate is likely about $6½ billion, $1½ billion more than NASA budgeted. Moreover, the earliest possible launch date is September 2015.
Given that construction is so far along, you've got to wonder why NASA misjudged things so badly. You would think that the agency had learned its lesson building the Hubble Space Telescope, which was supposed to take just four years to assemble when construction began in 1979 but ended up taking 11 years to reach space. The loss of the Space Shuttle Challenger in 1986 didn't help, but the HST project had numerous problems of its own making.
So what went wrong with JWST?
According to the review panel's final report, NASA officials made two "fundamental mistakes" when the project underwent a major Confirmation Review in July 2008. First, the panel found, "the Project Budget presented for Confirmation was not based upon a current, bottom-up estimate of projected costs." Second, project managers failed to factor in — and provide funds for — development problems that were likely to occur.Even to meet a 2015 launch date, NASA will need to pump an additional $250 million into the project's budget in fiscal 2011 and 2012 — funds that the agency isn't likely to get from Congress. If forced to find that money internally, the agency will likely have to cancel or defer other space-science programs already under way.
Perhaps more urgently, the panel recommended that NASA administrator Charles Bolden yank project management from its Goddard Space Flight Center and instead run the effort from a dedicated office at the agency's Washington headquarters. Bolden, in response, supported the panel's findings and is appointing a new JWST program director.
The news isn't all bad. The review panel found the technical state of the project to be sound and its scientific goals intact. Money spent to date hasn't been wasted, it noted in an Afterword, and "no technical constraints to successful completion have been identified." Once in orbit, the Webb telescope is expected to have the ability to look back 13½ billion years, to when the universe was just 2% of its current age and the first galaxies were forming.