Defending JWST

The article in the Nov. 12

issue of Space News written by Len Fisk and A. Thomas Young [“Experience as a Criterion for Leadership,” Commentary, page 13] makes a strong argument for experienced management in controlling costs of NASA missions.

The authors call the James Webb Space Telescope (JWST) “the most egregious example” of a mission that

cost much more than

originally was estimated. In 2005, a large overrun was attributed to JWST. A significant fraction of these costs occurred during transition periods at NASA:

It took NASA more than a year to approve a

European Space Agency (ESA) launch vehicle and formalize commitments to ESA. The adjustments at NASA

headquarters and the

centers to full-cost accounting brought its own set of challenges.

In that year, we served on the JWST Science Assessment Team to examine the case for JWST and recommend descopes and simplifications to the science mission. Working with these recommendations, JWST was replanned to a total cost (inception through launch) of $3.7 billion. This was comparable to the costs (in today’s dollars, using NASA’s new accounting methodologies) of other major space observatories such as the Hubble Space Telescope or the Chandra X-Ray Observatory from inception to launch. The estimated cost today of JWST, two years later, is $3.6 billion.

In February 2007, NASA and its partners demonstrated that all the enabling technologies had reached a maturity of Technology Readiness Level 6, more than a year in advance of the mission preliminary design review, which is scheduled for

March 2008

. In addition, most of the science instruments and many other critical subsystems have passed their critical design reviews. These milestones have significantly reduced the uncertainty in costing major items under development.

The reasons why JWST

has met its technical challenges successfully and held to its budget and schedule lie with NASA management. NASA funding for JWST has remained stable and consistent over the past

two and a half years. Its program manager, Phil Sabelhaus, has met the inevitable challenges within tight constraints of budget and schedule, without impacting resources outside its designated reserves. The science community has been a partner in this process, by considering potential descopes and making recommendations to reduce risk.

Next year, JWST will undergo its non-advocate and preliminary design reviews and will reach its peak funding year. While it is important to critically examine problems in mission management within NASA, it is equally important to acknowledge the successes. JWST now stands as a model for managing the largest NASA missions.

NASA’s science missions

consistently have led the world in terms of their scientific audacity and their ability to transform our view of the

universe. Missions like the Hubble Space Telescope (which

Dr. Fisk oversaw from the Challenger delay through its repair) have the unmatched power to inspire the public and school children across the globe. The James Webb Space Telescope, the largest optical-infrared space telescope ever to be flown by the United States and its partners, has the potential to be as transformational. Rigorous management is a necessary, but not sufficient requirement to achieve such successes. The other key attributes are imagination, vision and a willingness to push the technical and scientific requirements into the unknown – these are also strengths of NASA’s space science program.

Matt Mountain

Director, Space Telescope Science Institute

Kathryn Flanagan

Head, JWST Mission Office,

Space Telescope Science Institute