Webb's science instruments must be fully tested before launch. The Optical Telescope Element Simulator (OSIM) is a critical piece of test equipment that simulates the beam of light that the telescope will deliver to the science instruments, and will test the instruments to make sure they work as a package before we assemble them with the telescope.

OSIM will undergo its own cryo-vacuum verification test and calibration this year.

The flight Mid Infrared Instrument (MIRI) was received at Goddard Space Flight Center in May 2012, and will undergo electrical checks with ISIM systems and then will be mounted to the ISIM structure this year.

The FGS/NIRISS was received at Goddard later in the summer and will follow the MIRI through the steps of electrical and mechanical
integration with the ISIM.

Both the NIRCam and NIRSpec flight instruments are also scheduled to arrive at Goddard within the next year, and will also be mounted to the ISIM structure. Once all four science instruments are integrated with the ISIM, the assembly will then undergo an extensive test and verification program.

Major modifications to Johnson Space Flight Center's enormous Chamber A were completed this summer; it will continue undergoing tests in the next year in preparation for testing the observatory before launch.