Summary: Never discount your talents or abilities, never be discouraged about your worth or usefulness in the kingdom. You may think you can't contribute very much, but even small things are important in the kingdom of God.
On April 14, 1970, 56 hours into the Apollo 13 mission, astronaut Jack Swigert was asked by mission control to “stir” the oxygen tanks. Within minutes there was an explosion and the race was on to save the lives of the men on that spacecraft. Here’s what happened.
The no. 2 oxygen tank used in Apollo 13 was originally installed in the Apollo 10 module. Technicians removed it to make some modifications, and during the procedure the tank was dropped 2 inches. That drop was enough to jar an internal fill line. They replaced the tank with another one for Apollo 10 and did an external inspection of the tank. No one knew about the internal damage and the tank was later installed in Apollo 13.
This next part is a little complicated, so bear with me. The oxygen tanks were designed to run off the 28-volt DC power of the command and service modules. But, a redesign allowed them to also run off the 65-volt DC ground power at the Kennedy Space Center. All of the components in the tank were upgraded to accept 65 volts except the heater thermostatic switches, which were overlooked. The switches were designed to open and turn off the heater when the tank temperature reached 80 degrees F.
During pre-flight testing, tank no. 2, the damaged one, showed anomalies and would not empty correctly. It could have been because of the damaged fill line. Technicians decided to use the heater to "boil off" excess oxygen in the tank. This required 8 hours of 65-volt DC power. That procedure may have damaged the thermostatically controlled switches on the heater which, you recall, were designed for only 28 volts. The theory is that the switches may have welded shut, allowing the temperature inside the tank to rise to over 1000 degrees F. It’s believed that the high temperature damaged the Teflon insulation on the electrical wires to the power fans within the tank.
Apollo 13 blasted off as scheduled. But 56 hours into the mission, the power fans were turned on inside the tank; it was a standard procedure called “stirring the tanks.” The exposed fan wires shorted, causing the Teflon insulation to catch fire. This fire spread along the wires to the electrical conduit in the side of the tank. That became compromised and eventually ruptured, causing the oxygen tank to explode. The explosion the other oxygen tank and parts of the interior of the service module and blew off one of the bay covers.
The next time someone tells you “little things don’t count,” remind them of Apollo 13 and how dropping an oxygen tank 2 inches almost cost the crew their lives.
Spark plugs are rather small, but without them the engine in your car won’t run and you won’t be able to get anywhere. Microchips that keep your computer running and hold billions of bits of information are usually smaller than a thumbnail. Athletes lose races by a hair, politicians lose elections by a vote, vacuum cleaners won’t run because a tiny screw is missing…it just keeps adding up. Little things do count.