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Stewart Woodward

More than a "Rocket Scientist"

Continuing from the current HPHS 1955 Newsletter, here is Stewart Woodward's remarkable account of his experiences as a "rocket scientist", an aerospace engineer:

Would you please indulge a retired rocket scientist as he reminisces his experiences in the rocket profession? To be very accurate I was an aerospace engineer, but nowadays it doesn't take a rocket scientist to do a lot of tasks so I thought there would be more work opportunities to be an aerospace engineer.

People often asked me if I knew the astronauts. No. The spacecraft was a completely different organization than the launch vehicle. The astronauts spent all their time in Houston or at simulators in the KSC industrial area. I did see a few at meetings. I will tell you about the closest I came to being one. My office was in a trailer next to the Fuel Area where I was lead engineer for the Apollo/Saturn. I had to park my car at the entrance to the launch complex. There was a NASA shuttle van that circled the perimeter road that you could ride to your work area. Most of the time I decided not to wait for the shuttle and would walk or jog to my office. For public support NASA started running bus tours of Kennedy Space Center. Just outside the complex fence on the way to my trailer they built a bus parking area and grandstand where the tourist could stop and get their closest look at the pad and Saturn V . I was jogging past while the tourist were taking pictures of the rocket one day when I heard one kid say to his parents, "Look an astronaut in training." Naturally I ran a little faster.

As my first job I was assigned to Atlas ICBM base activation out of Warren AFB in Cheyenne. The Atlas was also used to put satellites into orbit and as well as John Glenn's Mercury Capsule. I was working on a launch site near Ted's Place. (Intersection of the Poudre Canyon Highway and the Laramie Highway.) The Atlas was unique in that the fuel and oxidizer tanks which make up the body were very thin stainless steel and order to save weight there was no support structure or ribs. The rocket could not structurally support its own weight. The tanks had to be pressurized at all times with Nitrogen. If you lost pressure it would collapse just like a flat tire which could permanently damage the ICBM. I was in charge of some checkout tests at the site. The Atlas was stored horizontally at ground level in a concrete building. The test I was running opened the coffin roof and the Atlas was erected in launch position with most of the rocket above the building. That was the situation we were in when we began hearing gun shots in all directions. Ted's Place is in a bowl like valley. We realized that the day we had chosen for our test was the start of deer season. There were crazy hunters swarming all over the hillsides around us firing at everything that moved. If one of those stray bullets had hit our rocket it would have probably exploded like a balloon. Man did I ever sweat until we got the Atlas down and the roof closed!

I was next assigned to an Atlas base in Vermont next to Lake Champlain near the Canadian border. These were more advanced silo launch sites where the Atlas was stored underground in a vertical position and raised on a huge elevator to the surface for launch. We had just about completed our scheduled activation and the Air Force would have taken over the site in a month or so when the Cuban Missile Crisis hit. Immediately SAC wanted every possible ICBM launch site to go on EWO (Emergency War Orders). The local Plattsburgh AFB decided that their crews were not 100% ready to run the launch site so they contracted with my company, General Dynamics-Astronautics, to provide experienced engineers around the clock to help them operate the site. I was assigned a 12 hour shift as the tech rep. Up to this point in my career working on an ICBM had been fun, like a kid with an erector set. All of a sudden here came a real warhead with and H-bomb inside. I was underground in the firing room with the 5 man launch crew. The commander, a major, had a .45 pistol strapped to his hip. The news was reporting Russian ships steaming toward Cuba with more missiles. Secret messages started coming in over the radio and I would have to leave the room while the SAC guys decoded them. Were these orders to launch a nuclear bomb toward Russia? Having run so many practice countdowns I knew that the automatic launch cycle often got hung up. I had learned many of the tricks to get the launch back on track. I was really sweating. I had not been brain washed to kill hundreds of thousand people. If a launch got hung up-could I force myself to push the right button or kick the right control? I don't know!

During my days underground I soon learned that the Air Force was more unionized than the civilian construction crews I had been working with. Each airman was trained to do only a certain job and was not allowed to do another job. Sitting at the Launch Console you basically had a green Standby light. That meant that all the many valves and electrical systems were in a position to start a launch countdown. There were always motors and other vibrations in the ground service equipment around the Atlas. A limit switch on an air conditioning actuator or propellant valve might vibrate loose on rare occasions. OOPS a big red light instead of a green Standby on the console. None of the 5 man launch crew was trained in maintenance. They would have to call in a maintenance crew from across Lake Champlain. It might take a day before the maintenance crew got their act together and arrived. Meanwhile the red light was also showing up on command consoles at SAC HQ in Omaha and in the Pentagon. The poor launch commander started getting calls from all of these upset generals. Why wasn't he protecting the country? One of the launch commanders had an idea during one of these crises. As a civilian tech rep I wasn't supposed to be there. Therefore he had no specific orders that I couldn't fix the problem. Could I? Sure! I would then take a headset, walk down a long tunnel by myself, through two, one foot thick steel doors and down stairs past the various levels of support equipment surrounding the ICBM to where I thought the problem might be. They never sent an airman with me because they were not supposed to do any maintenance. I would plug my headset into the intercom jack to talk to the launch commander and bend the switch back into position. Eureka! A green Standby light on the console and everyone up to the president was ecstatic.

After one of these lonely journeys by myself for communion with the rocket, as I started out I noticed a catwalk as I passed near the warhead. I climbed out and sort of sat on the warhead to contemplate my situation and the world. I therefore I may be the only person that you have met who was sat on a H-bomb on top of a ICBM poised to be launched at Russia.

Shortly after this the Russian ships turned back, the crisis was over much to my relief, and I was transferred to Cape Canaveral to work on peaceful moon rockets.

At the time that I became Lead Fuels Engineer on the Saturn V moon rocket, the liquid oxygen was stored on the perimeter of the launch complex in a large insulated tank. It was transferred across the field and up the Umbilical Tower using huge centrifugal pumps. Because LO2 is -297 degrees F all those moving pump parts must be chilled down very slowly to prevent leaks and avoid pump binding. So hours before the loading of the Saturn V started, a small amount of LO2 was allowed to flow through the pumps and out a drain in to the adjacent swamp. This was normally not a problem. The LO2 vaporized and the wind blew it away. It quickly mixed in with O2 already in the air.

Apollo 13 was different and this should have been a premonition of the explosion that was later to happen on the way to the moon. We were doing a CDDT, Countdown Demonstration Test, a dry run for the Apollo 13 launch. The day was overcast, not a breath of wind and the humidity and temperature were just right. On that day the pure oxygen draining into the ditch next to the road did not dissipate. We evidently had a huge cloud of pure oxygen hanging over the road. You have all heard the stories of what happens in a hospital oxygen tent if you light a cigarette. In a 100% oxygen atmosphere it almost explodes it burns so fast.

The Security Police manned the guardhouse at the entrance to the launch pad. Just before we started loading the launch vehicle with fuel and oxidizer the pad was officially cleared. Now everyone working out there kept close tabs on where we were in the countdown and would clear the pad well ahead of time so no one was usually there. But this was the big moment for the Security Police. They would get in their patrol cars and drive around the pad perimeter road with red lights flashing and loud speakers blaring, "Clear the Pad," and would normally return to the roadblock and report to the test conductor that the pad was officially clear for propellant loading and launch. That day as we followed the patrol cars around the pad on our console television monitors, they entered a fog bank next to the oxygen facility. Normally this would have been condensed moisture from the humid air caused by the cold oxygen gas, but for Apollo 13 it evidently was pure oxygen. As the patrol cars drove though the cloud the hot grease on the engines caught fire. We saw the Security Police jump out and run to safety. Then we watched as the patrol cars burned with the oil, grease and gasoline acting as the fuel and the pure oxygen. The next day the road had melted metal all over it. We had our own oxygen blast furnace just as in the steel mills.

This last story is my favorite experience. I think it illustrates that although most of the public thinks it was computers, high technology and well planned procedures that got mankind to the moon, you have to give a lot of credit to old fashioned human ingenuity.

The two upper stages of the Saturn V were fueled with liquid hydrogen. LH2 is -423 degrees F. 850,000 gals. of it were stored in a vacuum insulated tank in my Fuels Area. The LH2 was forced under pressure through vacuum insulated pipes across the field and up the Umbilical Tower at 10,000 gals per minute to the launch vehicle. In the launch vehicle tanks you could not afford the weight of a double wall vacuum jacket, only a layer of plastic foam. Once the tanks were full, you were losing liquid fuel at a high rate due to boil off. Therefore once we were loaded we switched to a computer controlled topping valve to match the liquid hydrogen vaporizing during the several hours before scheduled liftoff.

We had only a few minor problems with our hydrogen system. And then came Apollo 11. Our first attempt with Armstrong, Aldrin and Collins to land on the moon. We knew the whole world was watching. The USA Vice-President was walking around the control Room shaking hands. Don't bother us we wanted to say. I would sit there for hours at the hydrogen console very tense during loading. I had four large TV monitors in front of me where I could call up any of over a hundred TV cameras to watch various sections of the fuel system. We had hundreds of electronic gas detectors and flame detectors along the pipes looking for problems. You can imagine when something as cold as -423°F flows through a metal pipe or valve, the contractions that take place and the possibility for leaks. You really sweat hoping nothing will go wrong or that you will know what to do. On Apollo 11 we had just finished loading the S-IVB upper stage and switched to the Topping Valve when the monitor on the 200 foot showed a large white cloud. A leak! We quickly shut down the main transfer line valve, purged and inerted the leak area remotely. Even static electricity from the leaking hydrogen gas can ignite it and cause a catastrophe. How do you inert a liquid hydrogen line. Nitrogen used in most fuel situations would freeze solid. You use Helium gas with a freezing point of -452°F.

We knew we could not launch unless we could keep topping LH2 into the rocket. Over the intercom I called the chief test conductor and told him we had a problem. In previous countdowns even if you thought you could solve your problem he would say, "Test scrubbed." And hundreds of engineers and techs would pack it in. All because of you. On Apollo 11 with the world watching the test conductor came back , "Fix it."

I called downstairs to my emergency crew standing by. Two mechanics, a safety engineer, and a fuel system engineer jumped in their government car and started out the several miles to Complex 39A. We were following them with a TV camera on top of the VAB and right behind them we saw the van carrying the 3 astronauts out to the Apollo as scheduled after completion of propellant loading.

My guys got out of their car, climbed up the steps to the launch platform, went into the elevator and up the umbilical tower to the 200 ft. level. On another monitor I could see the astronauts go up the elevator to the 300 ft. Level and start to get into the spacecraft. When the emergency team reached the 200 ft. level and examined the Topping Valve it looked as if the leak had been around the valve bonnet. They thought that tightening the four bolts holding it might compress the gasket and correct the leak. The problem was that with all the cold escaping, moisture from the air had condensed and frozen over the bolts. Now under several inches of ice there was no way you could get an open end wrench on the bolt heads to cinch them up. They were afraid to chip at the ice with hammers. A spark might ignite any residual hydrogen gas in the area. What were we to do? Our computers and all the technical procedures didn't tell us. Meanwhile the astronauts were buttoning up the spacecraft and there was no way we could launch them.

Then the Fuels Engineer on the scene had an idea. The emergency crew were all wearing hard hats (helmets). There was an emergency eye wash and shower on the 200 ft. level in case of a fuel spill. A water source! The Emergency crew took off their safety helmets and formed a bucket brigade to pour water on the ice just like the neighbor ranchers did when their friend's barn was on fire. After about 10 minutes they had melted the ice. They used the wrench to tighten the bolts. We opened the main valve and there was no leak. The emergency crew cleared the pad; we topped off the Saturn V with liquid hydrogen.

An hour later we launched the first men to the moon.

Now you know that it wasn't computers or high technology that were the crux that got the first men to the moon. It was an old fashioned bucket brigade just as our forebears had used.