Apollo 13

[Jason Thompson]

I think that apollo 13 had incredibly good luck,considering that there spacecraft had an explosion a 100 thousnd miles from earth and somehow they were supposedly able to survive in space for another several hundred thousand miles and land unharmed . This to me seems like UNBELEIVABLE GOOD LUCK

Nothing unbelievable about it. The sequence of events is described in great detail in a number of places.

[Echnaton]

Redundant systems and expert knowledge saved the A13 crew and those are not a mater of luck.  They are the product of hard work and clear thinking.

[smartcooky]

I have just finished reading a fascinating article about Apollo 13, and I thought I would share it since it doesn't seem to be mentioned here.

It takes the view that the safe return of Lovell, Haise and Swigert was not so much attributable to a series of lucky engineering breaks and last minute "ad hoc" pieces of brilliant engineering, which is the commonly held view of Joe Public, but rather it was down to the prior endless training, endless simulations and dedication of the NASA staff, many of whom prepared themselves for just such a catastrophe long before Apollo 13 .

Much is made of the lengths to which John Aaron and his electrical guys went to in order to come up with a start sequence for the CSM prior to reentry, but what is less known is that they had even bigger problems in getting the LM to start up so that it could be used as a lifeboat in the first place, and that they had actually worked that scenario before as a simulation.

In fact, they came to the conclusion that if they had not have already worked out the start sequence prior to the event of Apollo 13, they would not have had time to work it out in "real time", and would have lost the crew.

It is a 2005 article, but it really is a good read for anyone interested in the Apollo programme.

http://spectrum.ieee.org/aerospace/space-flight/apollo-13-we-have-a-solution/0

[raven]

I have 'Lost Moon', and it mentions the lifeboat scenario been tested in a simulation shortly before the launch. This idea had almost certainly been in place even before the LM flew manned, as one reason NASA was so initially so leery of sending Apollo 8 to orbit the moon was because the LM wasn't ready yet and therefore could not act in this role in the event of an emergency.

[Obviousman]

There was little that had not already been explored.

One that comes to mind (IIRC) is using the LM to charge the CM re-entry batteries; it was designed to be the other way around.

[ka9q]

BTW, the article doesn't really make this clear, but many of the power transfer relays on the CSM and LM were motor-operated, which means they needed power to operate.

I'm actually surprised that the LM wasn't able to power itself up without bootstrap power from the CSM. That doesn't make a whole lot of sense, but there should be enough information in the available manuals and schematics to figure out what they actually had to do.

I know that when the LM was launched, it ran a few small loads on its own batteries (probably heaters) until power from the CSM umbilical could take over. In that state it should have been possible to power up the LM on its own. It could be that after the umbilicals were connected, the motor-driven relays in the LM completely disconnected all of its batteries and that's why they needed power from the CSM to reconnect them.