Thursday, June 30, 2011

"Some exposed wires."

If you sit down and watch any one of the half-dozen documentaries on Apollo 13 that can be found on YouTube, somewhere around the time of the explosion, the narrator will say something to the effect of, "Little did the astronauts know that there was a pair of exposed wires in the service module." Even the movie sums it up by saying that the explosion was caused by a defect that occurred years before the flight.

For years, I bought this explanation, as it seemed to be the only one offered. But I finished Lost Moon last night, and now I know a little bit better. The exposed wires are the very end of the whole thing. To paraphrase the book, the commission assigned to investigate the accident knew there couldn't possibly be one smoking gun, and that there had to be a number of problems for things to go THAT wrong in the spacecraft.

Allow me to explain that last statement. Even in the movie, the character of Sy Leibergot says that his instruments are reading a quadruple failure, and that that CAN'T happen. It had to be an instrumentation problem. There's a backup system for every system, and a backup for every backup. Almost everything was triple-protected, so the very concept of things going so wrong was considered impossible.

The epilogue of the book covers a lot more detail, but I think I can explain things here. The company that won the government contract to build the Apollo spacecrafts subcontracted out the making of the oxygen tanks. Inside the tanks were a fan, a temperature gauge and, believe it or not, a heater. Why a heater? Because it's very cold in space, and if the liquid oxygen inside the tanks got too cold, it could solidify to the point of being unable to pass through fuel lines.

At first, these things inside the tank were designed to handle the 35 volts of output from the spacecraft. But then it was realized that the launch pad folks used much higher voltage when prepping the ship. So the tanks were upgraded...everything except the thermostat, which was overlooked. That was the first part of the problem.

The next part was when fuel tank number two was switched out of one rocket and into another. Rather than move just the tank, the entire platform carrying the tank was moved. Unfortunately, one of the four bolts holding it in place wasn't removed. When the crane tried to remove the platform, the bolt held and the platform slammed back down. This was a relatively minor jolt, and the engineers on site proclaimed the tank still usable. That was problem number two.

It was realized that the tank wasn't 100% when there was a launch test. Afterward, the technicians attempted to empty tank two of its liquid oxygen, and discovered that the jolt it had experienced had probably knocked a drainage line out of place. But this was no problem, as they could use the heater to burn off the oxygen. The only time the drainage line was used was on the launch pad. Beyond that, the tank could still be used in space. That would be mistake number three.

So they snapped on the heater and watched the gauges to make sure it never went over 80 degrees inside the tank. There was just one little problem with that concept, and that being that the main temperature gauge topped off at 80 degrees. It couldn't possibly get hotter than that when the craft was in space, so why design the gauge to read anything higher? When they turned on the heater, they managed to fuse the thermostat open; now it would read nothing. The heater then brought the temperatures inside the tank to 1,000 degrees, cooking off the Teflon coating on the wires that led up to all the devices inside the tank. This makes mistake number four.

And so comes the final act in the series. Sy Leibergot, not liking the data on his screen at mission control, asked for a stir of the tanks. When Jack Swigert flipped the switches to do just that, the fans inside the tank started to whir...and finally gave off a spark from the exposed wires. The spark ignited the literally explosive oxygen inside the tank, and it promptly blew off the side of the service module. It also created a leak in the system so that fuel tank one would start venting its oxygen into space.

This isn't just theory. The entire incident was recreated right here on Earth, using an artificial vacuum at the NASA space center. Just as it had happened in space, the fuel tank exploded, taking off an entire side of the mock service module.

There was a bit more to the story, like what made Fred Haise so ill toward the end of the flight, and why Apollo 13 kept running shallow through the re-entry corridor. Humorously, there was also the bill that Grumman, the manufacturer of the LEM, was going to send North American Rockwell, the guys who put together the command and service modules.

This has been Everything, with your host Jerry Hathaway.

No...I don't think so.

Anyway, I'm hoping some of you found this as fascinating as I did. Perhaps you're not as amazed at things like space travel as I am. And I PRAY none of you think the whole moon landing stuff wasn't faked. ("I'm telling you! The little scratch in that ancient piece of film is a wire holding the 'actornauts' up!")

While I'm on this subject, I'll tell you why I'm not one of those lunatics who believes such nonsense. The conspiracy theorists who gripe about these things seem to have reams of evidence pointing to their correct assumptions. But when I lived in AZ, I had befriended a security guard, Dave. He had worked in national security at one time, and his efforts in Washington demonstrated one thing very clearly to him: Washington can't keep a secret. There are usually too many people involved in any one decision, and at least one of them is sure to open his or her mouth at the wrong time.

One of his security stories has crept into my head, and I can't shake it, so it must be told. The government apparently shelled out a pretty dollar to a contractor to build an unbreakable lock for storage facilities. After examining the product and being satisfied with it, Dave piped up. "I can get through that lock in less than one minute with the right materials," he said. The contractor scoffed and dared him to try.

So Dave ran off and got an air conditioning tuneup kit from his car and a hammer. Using the hose and valve in the kit, he emptied a can of Freon onto the lock. Then he took the hammer and whacked the lock. It promptly shattered, right in front of some very important military folk, thoroughly embarrassing the contractor.

Ahhh...I miss those chats with Dave.

* * *
In other news, Becky's in panic mode. We're down to our last few dollars, and money looks really tight right now.

What she doesn't realize is that it only LOOKS tight. We're going to have plenty of money in just a couple of days, and we have most of our rent already set aside. There's plenty of food in the pantry and we have clean clothes. Everything is rosy in comparison to how I was "living" in AZ.

I understand her thinking, though. She wants a comfortable cushion between her and being penniless. Somewhere along the way, we tripped over our plans to start saving for the wedding in several years, and nothing has been put aside. On that front, I've been waiting for her to put money aside so that I could match it the next month. Maybe what I need to do is start us off so she can be inspired to match me.

And that's all I have right now, folks. Be well, and DFTBA!

No comments: