Lee Feinberg, the optical telescope element manager at the Goddard Space Flight Center in Greenbelt, Maryland said that completing the assembly of the 18th mirror "is a very significant milestone" and the culmination of over a decade of design, manufacturing, testing and now the assembly of the JWST's mirror system.
The mirrors were installed with a robotic arm, and each hexagonal-shaped mirror measures about 4.2 feet (1.3 meters) across and weighs almost 88 pounds (40 kilograms). The primary mirror with all 18 segments installed is 21.3 feet wide.
With the completion of mirror installation, the JWST team has reached closer to launch the giant telescope that will one day unravel hidden secrets of the universe, Grunsfeld continued.
When the James Webb Space Telescope is completed, it will replace the infamous Hubble Space Telescope.
The James Webb Space Telescope is set to launch atop an Ariane 5 rocket from Kourou, French Guiana, in October 2018. The infrared telescope will allow astronomers to study those regions of the universe that are inaccessible for the Hubble.
The JWST will essentially be a large infrared telescope with a 6.5-meter primary mirror. It was pretty much THE go-to telescope, and it definitely got results. Ball Aerospace & Technologies Corp. built the mirror segments, and Northrop Grumman subcontractor Harris Corporation is carrying out the mirror assembly and installation.
According to Sky & Telescope, construction of the huge mirror began in November 2015, and NASA's engineers have now finished placing the last of the mirror's 18 segments.
But the celebration was short-lived as more work are still needed; project manager Bill Ochs said they will soon install other optics and proceed to testing of components to make sure that the telescope can withstand a rocket launch. After the massive mirror array is installed, the aft-optics and secondary mirror will be installed. The last piece of the state of the art space telescope is its Integrated Science Instrument Module. "After acoustic, vibration and other tests at Goddard, we will ship the system down to [NASA's] Johnson Space Center in Houston for an intensive cryogenic [extremely cold temperature] optical test to ensure everything is working properly".
"Near-Earth Objects are potential space resources and the James Webb Space Telescope will be one of the best tools to identify these resources that will help humanity expand beyond the Earth into our Solar System", said PSI Research Scientist Vishnu Reddy, a co-author on the paper. NASA leads this global space project in partnership with the Canadian Space Agency and the European Space Agency.