This is a sketch of the assembled WIRE Spacecraft.  The aperture shade prevents sunlight from interfering with the gathered data.   The star tracker keeps track of the position and location of the spacecraft.   The solar panels are absorb sunlight and use this solar energy for electrical power.

The WIRE Telescope

The telescope mirrors are coated in gold because it reflects infrared light very well.  Gold even reflects infrared light better than silver, which is commonly used. 

The WIRE Cryostat

Notice the aperture shade to protect from the sunlight as described above (upper picture).  The cover helps keep the instrument cold and under vacuum during launch.  Once in orbit, the cover is ejected.  The cryostat is painted white to better reflect the sunlight and help keep it cool.

The Assembled WIRE Spacecraft

These images show the assembled WIRE Spacecraft as it will be launched into orbit.  Notice the black solar panels and star tracker described above, and that the cover is still present.