NASA’s Webb “Pathfinder Telescope” Successfully Completes Second Super-Cold Optical Test

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Recently, a James Webb Space Telescope’s “pathfinder telescope,” or “Pathfinder” finished a second super-cold visual exam that resulted in a initial checkout of specialized visual exam apparatus designed to irradiate a telescope’s optics by to a instrument focal planes, and a procedures used to work this exam equipment.

Engineers check a James Webb Space Telescope's trailblazer telescope, after a second super-cold visual exam in Chamber A during NASA's Johnson Space Center. Credits: NASA/ Chris Gunn

Engineers check a James Webb Space Telescope’s “pathfinder telescope,” after a second super-cold visual exam in Chamber A during NASA’s Johnson Space Center.
Credits: NASA/ Chris Gunn

While a tangible moody elements of NASA’s Webb telescope are assembled, engineers are contrast a non-flight apparatus commissioned in a exam cover to safeguard that tests on a genuine Webb telescope after go safely and according to plan.

After a initial Pathfinder exam was finished in Jun 2015, a Aft Optics System or AOS, that includes a Tertiary Mirror and Fine Steering Mirror, was commissioned on a Pathfinder to prepared for a second test.

The Pathfinder is a non-flight reproduction of a Webb telescope’s core territory backplane, or “backbone,” that includes moody gangling mirrors. The full Pathfinder was afterwards given with special fiber-fed infrared visual sources that copy star images. Those star images, or infrared sources, along with a specifically instrumented infrared detector were used during a second exam to perform end-to-end contrast of a full Pathfinder telescope system.   The AOS and a source complement was built by Ball Aerospace and Technologies Corp’s comforts in Boulder, Colorado.

Artist's digest of a James Webb Space Telescope. Credits: Northrop Grumman

Artist’s digest of a James Webb Space Telescope.
Credits: Northrop Grumman

“Practice creates perfect. Since we will be contrast a world’s largest ever cryogenic telescope for a initial time in a world’s largest cryogenic exam chamber, we need to be gifted in regulating a exam apparatus so we can concentration on a opening of a telescope,” pronounced Mark Clampin, Webb telescope Observatory Project Scientist during NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

The moody backplane comes in 3 segments, a core territory and dual wing-like parts, all of that will support vast hexagonal mirrors on a Webb telescope. The trailblazer usually consists of a core partial of a backplane. However, during a test, it reason dual full distance gangling primary counterpart segments and a full distance gangling delegate counterpart to denote a ability to optically exam and align a telescope during a designed handling temperatures of -400 degrees Fahrenheit (-240 Celsius).  The exam apparatus used to exam a telescope primary counterpart and used to reason a whole trailblazer telescope were built by Harris Corporation of Rochester, New York.

The initial and second cryogenic visual contrast of a Pathfinder were conducted in Chamber A during NASA’s Johnson Space Center in Houston, Texas, where a contrast of a moody hardware will start in 2017.  The intensely cold conditions inside a cover are combined by using glass nitrogen and intensely cold helium gas by plumbing criss-crossing a aspect of dual large steel shells or “shrouds” nested inside a cover walls.

“Now that a second exam is done, it means that all visual exam systems have been checked out,” pronounced Lee Feinberg, Webb telescope Optical Telescope Element Manager during NASA Goddard.

A third and final predecessor exam called “Thermal Pathfinder” will follow in 2016 that will entirely exam all a exam apparatus indispensable to copy a heat sourroundings of space.  Once this is complete, all exam apparatus and procedures indispensable to exam a tangible full moody telescope  in early 2017 will be checked-out and ready.

The James Webb Space Telescope is a systematic inheritor to NASA’s Hubble Space Telescope. It will be a many absolute space telescope ever built. Webb is an general plan led by NASA with a partners, a European Space Agency and a Canadian Space Agency.

Source: NASA