With one month to go until the 25th anniversary of the Hubble Space Telescope's launch, its successor—the James Webb Space Telescope—was the topic of a March 24 hearing of the House Subcommittee on Space. The new telescope is scheduled to begin operation in 2018 and "holds the promise of producing revolutionary science that one day may rewrite textbooks," according to Subcommittee Chair Steven Palazzo (R-MS).
NASA's development of Webb, which began in 1999, has been riddled with setbacks and ballooning budgets that have raised Congressional eyebrows in the past. Initial estimates ranged between $1 billion and $3.5 billion with a launch date by 2011. Costs escalated and delays accumulated as NASA built the telescope, and the project was re-planned several times. In 2011 the House voted to scrap Webb, only to restore funding during budget negotiations with the Senate later that year. The project is currently subject to a congressionally-mandated $8.8 billion cost cap.
Several representatives, including Palazzo, expressed concern that further cost escalation could threaten other NASA programs such as "planetary science and even exploration programs."
John Grunsfeld, associate administrator for NASA's Science Mission Directorate, where the Webb Telescope is managed, said he was confident that the project is on track and has sufficient budget and schedule reserves. The GAO, which also testified, confirmed that the project appears fine so far, though it cautioned that risk of setbacks may increase during the system integration phase, which has just begun.
Tour the clean room for the James Webb Space Telescope
Despite these potential issues, both representatives and witnesses were excited about the science that Webb will enable. The star of the hearing was John Mather, senior project scientist for Webb, AAAS Fellow, and winner of the 2006 Nobel Prize in physics for his precise measurements of the cosmic microwave background radiation using the COBE satellite. He explained that Webb's extremely large and flat mirror will enable clearer images than ever before. The area of the mirror is five times that of Hubble's, and if it were stretched to the size of the United States the variations in height would be less than three inches. The whole apparatus packs to fit inside a rocket during launch and will unfold as it travels out to its future home, more than a million miles from Earth.
"We are an exceptional country for even dreaming up something like Webb," Mather said.
Such a precise instrument will show the very first population of stars that formed nearly 13.4 billion years ago. These stars have never been directly observed and will provide crucial information on how galaxies formed out of the universe's primordial stages.
Lamar Smith (R-TX) highlighted a second application of Webb."We may find biosignatures of life on other planets" by combining its observational power with other missions such as the Transiting Exoplanet Survey Satellite. The House Science Committee has demonstrated a particular interest in life on other worlds over the past two years.
While progress on the telescope has been challenging, Mather is looking forward to its launch. "I think Webb is the most important project I could be working on," he said.
An archived webcast and additional information are available on the subcommittee website. Mather has spoken to AAASMC previously about the Webb telescope.
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