The Large Angle and Spectrometric Coronagraph (LASCO) is a set of three "coronagraph" telescopes on-board the SOHO satellite. A coronagraph is a special type of telescope that uses a solid disk ("occulter" or "occulting disk") to actually cover up the Sun itself, completely blocking direct sunlight, and allowing us to see the atmosphere around the outside of the Sun (known as the "corona").

LASCO comprises of three telescopes (C1, C2 and C3), each of which looks at an increasingly large area surrounding the Sun. For teh first year-and-a-half of the SOHO mission, all three instruments worked perectly. However, in 1998 SOHO was accidentally "lost" in space after it received a bad command. The entire spacecraft lost power and essentialy froze solid for several weeks. Eventually -- miraculously! -- the SOHO team were able to relocate the spacecraft, regain control and slowly power-up and thaw out the instruments. Sadly, the LASCO C1 camera was lost as a result of this but the rest of spacecraft came through almost completely unscathed! Eight years later -- and over ten years since launch -- LASCO C2 and C3 (and most of the rest of SOHO!) continue to work extremely well, sending back images and data on a daily basis.