The Large Optical Test and Integration Site, or LOTIS, is a facility at the

Lockheed Martin Space Systems Lockheed Martin Space is one of the four major business divisions of Lockheed Martin. It has its headquarters in Littleton, Colorado, with additional sites in Valley Forge, Pennsylvania; Sunnyvale, California; Santa Cruz, California; Huntsville ...

Company in

Sunnyvale, CA Sunnyvale () is a city located in the Santa Clara Valley in northwest Santa Clara County in the U.S. state of California. Sunnyvale lies along the historic El Camino Real and Highway 101 and is bordered by portions of San Jose to the north ...

for testing large optical components under realistic conditions. LOTIS has large, thermally stabilized

vacuum chamber A vacuum chamber is a rigid enclosure from which air and other gases are removed by a vacuum pump. This results in a low-pressure environment within the chamber, commonly referred to as a vacuum. A vacuum environment allows researchers to con ...

, vibration-isolated optical benches, and a large 6.5 meter telescope (run backwards as a collimator) to create images for the test optics to view. It can generate images from the visible through the mid-wavelength IR. The fabrication error in the

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

main mirror is the classic example that shows the need for such testing. In this case, a test facility such as LOTIS was not easily available, so the completed optics were not tested as a unit, and instead relied on careful testing of the individual components. Unfortunately, due to a mis-assembled

null corrector A null corrector is an optical device used in the testing of large aspheric mirrors. A spherical mirror of any size can be tested relatively easily using standard optical components such as laser, mirrors, beamsplitters, and converging lenses. O ...

, one of the tests was wrong, and a mis- figured mirror was not discovered until the telescope was placed into service. This is exactly the type of problem that LOTIS can detect, since it is designed to test large optical systems as a unit by creating realistic inputs and operating conditions for them.

References

* *{{dead link, date=January 2018 , bot=InternetArchiveBot , fix-attempted=yes Mirrors Optics institutions Sunnyvale, California Lockheed Corporation