Jump-starting the Lunar Lander

[Bob the Unbeliever]

Engineers designing and thinking about as many possible points of failure, for the Apollo program, considered the possibility that the upper assent module would not start. It required a certain level of electrical current to open up the fuel and oxidizer lines, which had 4 valves each (as a redundancy).

If all worked as planned, the battery on the lower module would work through a connection that would be blown, once the assent engine started. Of course-- this was all taking place on the moon, so distant from any AAA help, that every thing had to be considered. And as far as they could, was.

There were written procedures in the astronaut's manuals. On how to "jump start" the assent module...

This video goes into more detail, and it's fascinating.

 

[ChristineM]

When the eurofighter typhoon was in development not to far from our office we could often see test flights and would listen in to the radio conversation. One extreme conversation lasted only a few seconds and your OP reminded me of it.

Pilot, "flame out, flame out..."
Ground control "please repeat"
Pilot,"are you ******* deaf, flame out, this thing is coming down"
Ground control "prepare to eject, emergency crew are mobile"
Pilot,".... Dont bother, you can bump start these things..."