NIRCam Set for NASA Tests
GREENBELT, Md., June 1, 2010 — A test unit for the Near Infrared Camera (NIRCam) instrument that will fly aboard the James Webb Space Telescope has arrived at NASA’s Goddard Space Flight Center and has been placed in a cleanroom for a year’s worth of testing.
The NIRCam will be the primary imager on the Webb telescope and will measure light in the spectral wavelength range from 0.6 to 5 μm. The unit that arrived at Goddard is actually an engineering test unit and not the actual NIRCam that will be part of the Webb telescope.
The NIRCam unit is wrapped up at Lockheed Martin, Palo Alto, Calif., for its shipment to NASA Goddard. (Image: Lockheed Martin)
The NIRCam is being built by a team at the University of Arizona in Tucson and at Lockheed Martin’s Advanced Technology Center in Palo Alto, Calif. The group is led by Marcia Rieke of the University of Arizona. Lockheed Martin built the NIRCam engineering test unit.
At NASA Goddard, the unit will undergo one year’s worth of testing to verify instrument interfaces and integration and test processes. The test device will be used to practice installation into the Integrated Science Instrument Module (ISIM) structure. The heart of the Webb telescope, the ISIM will house the four main Webb instruments. Measurements will also be made of the precise location of the NIRCam instrument within ISIM to later aid in alignment of the flight model. The NIRCam is a science instrument but also an optical telescope element wavefront sensor, which improves the resolution of the imaging systems.
The actual flight unit is currently being built; the outcome of the tests may lead to a change in handling procedures of the flight NIRCam, but not a change in the flight construction.
The actual NIRCam will study infrared light. Because the universe is expanding, light from the earliest galaxies has been stretched, or “red-shifted,” from visible light into infrared light. Humans can’t see infrared light but can perceive it as heat. NIRCam will be able to visualize infrared light, making the instrument essential for examining the early phases of star and galaxy formation and for studying the shapes and colors of distant galaxies. NIRCam also will help astronomers learn the age of stars in nearby galaxies.
“The NIRCam engineering test unit includes one fully functional optical channel and was used to demonstrate the hardware to be used in aligning the Webb telescope’s mirror segments,” said Rieke, who is a professor of astronomy.
The James Webb Space Telescope will detect the first light-emitting galaxies and star clusters to form in the universe after the Big Bang. The NIRCam design is optimized for finding these “first light” sources. The camera also includes features that will make it a wonderful tool for studying star formation in the Milky Way galaxy and for discovering and characterizing planets around other stars.
“A lot of hard work went into developing and testing the NIRCam engineering test unit,” said Diane Yun, NIRCam instrument manager at NASA Goddard. “We are excited to have it here at Goddard for ISIM testing. This brings us one step closer to achieving the science goals of NIRCam and the Webb telescope.”
The actual NIRCam flight instrument is scheduled to arrive at NASA Goddard in 2011 for testing and incorporation into the Webb telescope.
For more information, visit: www.jwst.nasa.gov
MORE FROM PHOTONICS MEDIA