NASA's James Webb Telescope Awaits Key Instrument TestNASA's James Webb Telescope Awaits Key Instrument Test

NASA is putting one of the key instruments meant to fly aboard NASA's next-generation telescope through its final testing to see how it will perform in space.

The Mid-InfraRed Instrument (MIRI) is being tested in a space-simulated environment at the Rutherford Appleton Laboratory (RAL) in the U.K., according to NASA.

MIRI will provide imaging, coronagraphy and integral field spectroscopy over the 5-28 micron wavelength range as one of four instruments on the James Webb Space Telescope, the successor to the Hubble.

The MIRI consortium of scientists and engineers has been working on the instrument for eight years and, once this final round of testing is complete, it will be ready for NASA.

The James Webb telescope -- a joint project of NASA and European and Canadian space agencies -- will travel much farther into space than the Hubble. NASA has pinpointed a destination called L2 -- a gravitational pivot point located 930,000 miles away on the opposite side of the Earth from the Sun -- for the telescope.

The idea is that the temperature at that point is cool enough and shaded from light from the sun and the Earth to obtain measurements that astronomers can use for research about the earliest days of the universe, according to NASA. Engineers designed MIRI to investigate areas related to those days, such as its first light and the formation of planets around other stars. However, they said that finding a way to keep the instrument at a temperature colder than on Pluto, which is required for it to perform its mission, was a big engineering challenge.

One function that the instrument potentially can perform that Hubble could not is to observe star formation resulting from an interaction among galaxies, NASA said.

MIRI is more sensitive to longer wavelengths of light that can penetrate dust, which tends to shield newly formed stars from view of Hubble or ground-based telescopes. This feature of MIRI also will allow it to tell the relative age of a galaxy, thus giving it the ability to distinguish between older ones and those recently formed, according to NASA.

In addition to MIRI, instruments that will go aboard the James Webb telescope include a near-infrared spectrograph, called NIRSpec; a near-infrared camera, called NIRCam; and TFI, a tunable filter imager, according to NASA.

Once current MIRI testing is complete, the instrument will be sent to NASA's Goddard Space Flight Center next spring for integration with the telescope.