Lab’s technology on board James Webb Space Telescope
Steve Little make sures that the upper surface of the zinc selenide blank is level to within one micron before starting to cut the grating. He puts an indicator gauge at the corners of the blank and adjusts the jacking screws on the fixture to get the blank level as Paul Kuzmenko looks on. Photo by Randy Wong/LLNL.
Last month, NASA’s James Webb Space Telescope (JWST), a partnership with the European Space Agency and the Canadian Space Agency, revealed unprecedented and detailed views of the universe, with the release of its first full-color images and spectroscopic data.
The cosmic objects that Webb targeted for these first observations were released July 12 and are available on the NASA website.
But those images and data were produced with a little help from Lawrence Livermore National Laboratory (LLNL), thanks to detector software support and development of a grism (also known as a grating prism, which is a combination of a prism and grating arranged so that light at a chosen central wavelength passes straight through).
A team of LLNL engineers diamond-machined a zinc selenide grism for the Near Infrared Imager and Slitless Spectrograph, a Canadian instrument onboard JWST. The grism operates over the wavelength range of 0.6 to 3.0 micrometers, with a primary science goal of performing exoplanet transit spectroscopy.
LLNL’s Paul Kuzmenko and Steve Little played critical roles in the fabrication and testing of the grism, which was delivered to the Canadian Space Agency in 2012.
“The pictures are amazing in resolution and detail, but I was more impressed by the infrared spectrum of the exoplanet Wasp 96B showing evidence of water vapor,” Kuzmenko said. “I’ve been involved with building and operating spectral instruments for many years. As we say in the business, ‘A picture may be worth a thousand words, but a spectrum is worth a thousand pictures.’”
A spectrum can directly identify the material composition of objects that we cannot directly access. Much of what we know about the composition of astronomical objects has been gained through spectroscopy. The element helium was first observed in the spectrum of the sun before its existence was discovered on Earth.
But LLNL’s contributions don’t stop there. During his Ph.D. studies, LLNL computational engineer Lance Simms had the opportunity to intern at Teledyne Imaging Sensors where the company was developing firmware to control Webb's infrared detectors. Shortly after Simms joined LLNL in 2011, NASA reached out to him and let him know that some of the code he had written during his internship was being used in the JWST firmware. He then joined the JWST team as a detector consultant for the NIRCam, NIRSpec and FGS/NIRISS instruments. For nearly 10 years as an LLNL employee, Simms has written firmware to optimize the performance of these instruments and helped identify/fix bugs in the code.
“The images that JWST has produced are so stunning they are simply hard to believe,” Simms said. “JWST proves that good things come to those who wait. And it shows that we are capable of achieving the near-impossible when we work together.“
The release of these first images marks the official beginning of Webb’s science operations, which will continue to explore the mission’s key science themes. Teams have already applied through a competitive process for time to use the telescope, in what astronomers call its first “cycle,” or first year.
The JWST is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars and probe the mysterious structures and origins of our universe and our place in it.
ContactAnne M. Stark
Related LinksJames Webb Space Telescope
Full-color images and spectroscopic data
Zinc selenide grism forthe Near Infrared Imager and Slitless Spectrograph
TagsSpace Science Institute
Physical and Life Sciences