What weighs more than seven tons, sports a chief component made of toxic metal mined in Utah, folds up like a gigantic complicated parasol, and promises to peer back 10 or 12 billion years to photograph the first galaxies? The James Webb Space Telescope.
[NASA illustration of the James Webb Space Telescope in position about 1 million miles from Earth. The sunshield, shown in blue, is nearly the size of a tennis court. The observatory stands to vastly enlarge our knowledge of the universe]
That is, if the JWST is launched.
Tuesday night, Jason Budinoff, an optical engineer for the partly-finished robotic space observatory, described the project during a public meeting of the Salt Lake Astronomical Society, held at the University of Utah. He works at the Goddard Space Flight Institute, Greenbelt, Md.
The Webb (named for NASA’s second administrator) has been under planning or construction since the late 1990s. Today all the components have been built, he said. “The next step is we’re going to bring it into a big room and put it together. … We’re probably three years out from having a telescope fully assembled and tested.”
The JWST is designed to orbit a region about 1 million miles from Earth called the Second Lagrange Point, where the pull of the sun and Earth are equal. It needs to be that far away so the infrared telescope will be cold enough to operate well. It will be shaded from the sun by a five-layer fabric device 69.5 feet by 46.5 feet, “almost as big as a Boeing 737,” NASA says. Blocking sunlight will allow the observatory to cool to its operating temperature of about -370 degrees F.
With a diameter of more than 21 feet, the 18-segment telescope mirror will be far more powerful than the instrument it’s to replace, the Hubble Space Telescope. “The bigger telescope you have, the more resolution you have,” he said.
[NASA optical engineer Jason Budinoff gestures as he explains how the telescope folds up for transport in a rocket. Photo by Cory Bauman]
The mirror was made of beryllium, a toxic metal whose only American production reportedly is the Brush-Wellman mine near Delta. The segments are gold-plated. The spectrometer alone is “big as a piano.”
The entire package will fold into a payload faring only 55 feet high and 15 feet in diameter, perched atop a French Ariane 5 rocket. Blasting off from French Guiana, the Ariane is a contribution from one of the project’s partners, the European Space Agency.
Some hangup in unfolding the observatory as it heads out from Earth has been identified as the biggest risk. If there is such “a deployment error,” Budinoff said, NASA will have will be no way to fix it.
However, prime contractor Northrup Grumman has “tested this system to death, and it works.”
The Webb Telescope will be operated from the Space Telescope Science Institute, Baltimore, which runs the aging Hubble Space Telescope. Webb’s lifespan is at least five years, with administrators hoping that will extend to 10 years.
Its exceptionally sharp optics are will take high-resolution images of everything from planetary disks around nearby stars to the most distant galaxies. The level of detail in the photographs is expected to be at least three times that of Hubble’s.
“The images that it’s going to make are going to make the Hubble images look like crap,” he said.
Budinoff predicted, “We’re going to discover things that we haven’t even thought about yet. … This one will see all the way back to the beginning,” the era when stars first began to blaze.
Another goal is to search for planets around other stars and find clues to the origins of life.
[A vast vacuum chamber that will test part of the observatory, shown in a view that Budinoff projected Tuesday night. Photo by Cory Bauman]
Those forecasts are based on the assumption that the telescope will get into space. Yet, after the expenditure of $4 billion and years of effort, there’s a chance it may not.
In March, the federal government’s General Accounting Office said the project — NASA’s largest — is over budget and has missed deadlines. The GAO noted that in 2010 the Independent Comprehensive Review Panel indicated that the earliest the telescope could be launched was in September 2015, “15 months after the baseline schedule.
“Further, the ICRP reported that JWST’s life-cycle cost would likely increase by $1.4 billion or more, $500 million of which would be required in the next 2 fiscal years.” It estimated that since Fiscal Year 2009, the project’s overall cost had risen from $4.963 billion to $5.095 billion. That estimate was based on launching the telescope in June 2014, but NASA’s goal now is for a 2018 launch. Generally, the longer a project is delayed the more it costs.
Instead of appropriating the additional money cited by the ICRP, on July 6 the House Appropriations Committee voted to terminate funding for the James Webb Space Telescope. The committee’s news release of July 7 said the telescope is “billions of dollars over budget and plagued by poor management.”
Budinoff said the appropriations bill hasn’t passed yet and the telescope’s funding is still under negotiation. He added, “It’s anyone’s guess what will happen.”