English: This view of the damaged Apollo 13 Service Module (SM) was photographed from the Lunar Module/Command Module following SM jettisoning. As seen here, an entire SM panel was blown away by the apparent explosion of oxygen tank number two located in Sector 4 of the SM. Two of the three fuel cells are visible just forward (above) the heavily damaged area. Three fuel cells, two oxygen tanks, and two hydrogen tanks are located in Sector 4. The damaged area is located above the S-Band high gain antenna. Nearest the camera is the Service Propulsion System (SPS) engine and nozzle. The damage to the SM caused the Apollo 13 crewmen to use the Lunar Excursion Module (LEM) as a "lifeboat." The Lunar Module "Aquarius" was jettisoned just prior to Earth reentry by the Command Module "Odyssey".