spacecraft were a Launch Escape System and a Spacecraft/Launch Vehicle Adapter, numbered SLA-17. The changes to the Apollo spacecraft between Apollo 13 and 14 were more numerous than with earlier missions, not only because of the problems with Apollo 13, but because of the more extensive lunar activities planned for Apollo 14. The Apollo 13 accident had been caused by the explosive failure of an oxygen tank, after the insulation of the internal wiring had been damaged by heating of the tank contents pre-launch—that the oxygen had gotten hot enough to damage the insulation had not been realized, since the protective thermostatic switches had failed because they were, through an error, not designed to handle the voltage applied during ground testing. The explosion damaged the other tank or its tubing, causing its contents to leak away. The changes in response included a redesign of the oxygen tanks, with the thermostats being upgraded to handle the proper voltage. A third tank was also added, placed in Bay1 of the SM, on the side opposite the other two, and was given a valve that could isolate it in an emergency, and allow it to feed the CM's environmental system only. The quantity probe in each tank was upgraded from aluminum to stainless steel. Also in response to the Apollo 13 accident, the electrical wiring in Bay4 (where the explosion had happened) was sheathed in stainless steel. The fuel cell oxygen supply valves were redesigned to isolate the Teflon-coated wiring from the oxygen. The spacecraft and Mission Control monitoring systems were modified to give more immediate and visible warnings of anomalies. The Apollo 13 astronauts had suffered shortages of water and of power after the accident. Accordingly, an emergency supply of of water was stored in Apollo 14's CM, and an emergency battery, identical to those that powered the LM's descent stage, was placed in the SM. The LM was modified to make the transfer of power from LM to CM easier. Other changes included the installation of anti-slosh baffles in the LM descent stage's propellant tanks. This would prevent the low fuel light from coming on prematurely, as had happened on Apollo 11 and 12. Structural changes were made to accommodate the equipment to be used on the lunar surface, including the Modular Equipment Transporter. Launch vehicle The Saturn V used for Apollo 14 was designated SA-509, and was similar to those