When put into service in 1990, the Hubble space telescope was supposed to last about 15 years. Thanks to servicing via spacewalks, it is still going pretty well. Unfortuantely, one of the cameras onboard has stopped working. The ACS (advanced camera for surveys) can detect light from the ultraviolet to the near-infrared end of the spectrum and has been invaluable for astronomers since it was installed in 2002.
The images and information that the Hubble telescope has provided has led to significant progress in understanding our universe...they likely would not have happened by this point without it. It seems every couple of years, the telescope faces challenges, whether it be breaking down or the threat of losing funding. Let's hope NASA keeps servicing Hubble until the next generation space telescope is put into place.
Image above from Hubble Heritage.