More of Your Apollo 13 Questions Answered by Jerry Woodfill


Our many thanks to NASA engineer Jerry Woodfill for taking the time to answer questions from our readers about our series on “13 Things That Saved Apollo 13.” Here is part 2 of the questions, and if you missed Part 1, here is the link. That’s Jerry above, in the image with Apollo 13 astronaut Fred Haise. We’ll have one more round of Q & A’s with Jerry in a subsequent post.

Question from Billy Wells: The Apollo astronauts were suffering from being very cold on the way back from the moon – one of them being sick with a fever at that same time. Why didn’t two of them put on the lunar space suits that were on the lunar module ? I would think that would have kept them from being so cold and miserable during that trip home.

Jerry Woodfill: Have you seen the movie “A Christmas Story” about Ralphie and his heart-felt longing for a “Red-Ryder-carbine-action-range-model-lightning-loader-200-shot-air-rifle?” Well the author and I went to the same school, 20 years apart. We even had the same freshman English teacher, Mrs. McCullough. You are wondering what this has to do with cold Apollo 13 astronauts. In the movie, Ralphie’s brother Randy is “space-suited” by his Mom for a walk to school in the frigid northwest Indiana wind-blown environment. (The wind-chill must have made Apollo 13’s cabin feel tropical. I know I experienced it.) Randy’s attire is space-suit-like, bulbous, tight, immobile and wholly uncomfortable. When the lad trips, he is prostrate on his back unable to right himself, his limbs flailing with a dying Texas cockroach.

None of the astronauts, by their comments, enjoyed wearing Apollo spacesuits because of this “Randy-Effect”. In fact, they were only required to don the garments during critical mission phases. During such times, a malfunction-leak in the cabin might cause a loss of pressure and death.

In this series, the replacement of Ken Mattingly by the robust footballer Jack Swigert was discussed earlier. This relates to your question. Yes, the sick Fred Haise needed warming. But the discomfort of the space-suit rather than the comfortable/cooler casual wear was a factor. Besides, as long as Fred remained dry, the casual attire retained his body heat. No breeze was present, and, I’m told, that the actual 98.6 body temperature tended to warm crewmen through radiant body heating. Their inert bodies encapsulated within their casual wear tended to retain radiated body heat. Also, Fred had to record on paper updated procedures. The handicap of a space-suit’s “Randy-Effect” would make writing/printing more difficult.

Someone did a later study about how cold Apollo 13 actually was. I know that 38 degrees F was sort of accepted as the temperature during the rescue. (This was the reported temperature in the far reaches of the dead Command Module quarters where Jack Swigert dwelled.) But other analysis found an environment not nearly as cold, especially in the lander. The customary “barbeque-rotational-solar” heating was always present. Nevertheless, Jim Lovell stated in the 40th Anniversary panel discussion I attended, “I actually did hug Fred to keep him warm as the movie depicts.”

Now back to Randy: My Mom made me wear long-underwear from the same store Ralphie asked Santa Claus for the “Holy Grail of Gifts”, a B-B gun. It was like the multilayered Apollo space-suit underwear. You had to stuff the “long-johns” into your socks so the Lake Michigan wind wouldn’t slice into your ankles like a frozen meat cleaver. Then she insisted on “scratchy” coarse wool pants akin to an astronaut’s outer garment. I think that is why Haise rejected suiting-up in his LEM lander attire. I know I would have rather been a little cold than trussed-up in Mom’s Indiana winter-wear. If I see Fred, I’ll ask him about this. He lives near here. But would you opt for the comfort of what’s pictured below over the more casual astronaut garments worn on Apollo 13?

Question from John McKenna: Are solid rockets affected by POGO as was Apollo 13’s second stage?

Jerry Woodfill: While there is scant evidence of a Pogo-like effect in solid rockets, there is a likewise serious threat of resonant oscillations. It is described as a common shaking problem for solid rocket boosters. The mechanism results from pulses of added acceleration caused by gas vortices. It is akin to the wake generated by a speed-boat. When these vibration vortices resonate with the natural frequencies of the solid rocket motor’s combustion chamber, the combined effect can cause a destructive shaking just as serious as a liquid booster’s POGO threat.

Question from LPScott: Hey Jerry…One of my favorite questions about the Lunar Lander…Why did they end the steps about 3 feet from the surface and make the astronaut leap those last few feet? Why not make the steps go on down to the landing pads? Even if the surface had been softer the last step would just sink in and they would not have had to jump?

Jerry Woodfill: I love this question. Thanks for asking it. The reason I like it is because I was a friend of the NASA engineer responsible for the LM’s landing gear. Unfortunately, I couldn’t locate him for an answer. (I did a Google and Switchboard search. He must have moved away. He retired years ago.) So I’m going to “speculate” slightly from my background with lunar lander engineering. I think, in part, it has to do with the gear’s shock-absorbing design. A “posterior” jarring uneven touch down might be so jolting and uneven as to cause the forward pod to cant significantly. In such an instance, that lower rung of the ladder might jam into a lunar boulder or even an irregular rise in the surface topography. Why chance such a thing? Make the ladder shorter to provide clearance. In one-sixth gravity, that last step is virtually a play ground skip off a children’s playground slide.

But this brings to mind a related account I think Universe Today’s readers will enjoy. Just several months before the July, 1969 landing, Neil Armstrong asked my friend to join him for a meeting with the Apollo Program manager, George Low to discuss the “one small leap (at least, as you said, three feet) for all mankind.” Each lander leg had, of course, landing pods. But what troubled Armstrong were the lunar contact probes extending another 5.6 feet beneath each of them. When they brushed the surface, the display panel lunar contact light would come on. This was the signal that the descent engine could be turned off.

Now, if you’ve watched the video of Buzz Aldrin’s leap backward onto the Moon from that last ladder rung, imagine what would have happened to Armstrong or Aldrin’s air-tight space-suit had the ladder’s leg contact probe bent up saber-style “inappropriately.” That would have spoiled Armstrong’s day. The result of Armstrong, Low, and my friend’s meeting was there would be no contact probe henceforth on any of the LEM’s forward ladder legs, including the Eagle.

Question from Steve Nerlich: Do you know if the scene in the movie “Apollo 13” where the actors all rip their medical telemetry off, in defiance of mission rules, really happened?

Jerry Woodfill: First, let’s review Jim Lovell’s book, renamed Apollo 13 (formerly Lost Moon). BTW, the best answer would come from Fred Haise and Jim Lovell. At times, either man might share what was embellished by Hollywood and what actually happened. For example, at the recent JSC 40th Anniversary panel discussion, Jim said, “That scene where I hugged Fred to warm him really happened.”

I checked the book. Interesting, that I randomly opened to page 269 which answers your question. I won’t quote it here, but I’m sure you have access to a copy. It pretty much answers your question(s) about the med-sensors.

Nevertheless, had I known your question, I’d have asked it at the Q & A at the 40th anniversary celebration. Should I encounter Fred (he lives near JSC.), I’ll ask him the question. But my thought is, “Yes, they removed the uncomfortable sensors, but probably not in the dramatic fashion shown in the film.” I’ve reviewed that cinematic treatment of the rescue dozens of times. Each time, I find something of interest to share with those I give presentations on the topic of the rescue. But generally, the screen play is a reliable recreation of events on board Apollo 13. Perhaps, I should do a “What’s Real/What’s Not” about the movie Apollo 13. While some have already created web-sites listing such, I have many more concerning the displays and caution and warning from my perspective, since I was a project engineer responsible for them. It might be a good way to encourage interest in manned space exploration. So thanks for the question.

Question from Chad: All of the books on Apollo 13 carry a certain tone of absoluteness… When the men of Apollo 13 became stranded, everyone involved seems to recall an attitude of “We Must!” My question is this: Looking back, was that an attitude that was held true at heart, or only projected outwardly. Obviously everyone involved on the ground was going to do EVERYTHING humanly possible to bring those men home safely, but to put it bluntly, failure was most definitely one of the possibilities. How did that weigh on your mind and heart? Did it help you (the plural you) work harder at the problem, or was a hindrance… Kind of a needle in your brain that jabbed at you constantly?

Jerry Woodfill: Chad…I’ll ask you to Google the name “Jerry Bostick”. His comment about how he came to author the phrase “Failure is not an option.” speaks to your question.
Also, I think these accounts kind of speak to what I felt then and still believe about “failure not being an option.”

I’d like to paraphrase and partially quote their content:

A mother and father’s son fell from a tree breaking his spine. The day he broke his spine, doctors said he’d probably be paralyzed for life. His parents said, “no way.” His mother recalled, “One of my comments at that point was from Apollo 13, which was, ‘Failure is not an option.'” Well, with the same resolve exhibited by the movie Apollo 13, the father searched the Internet and found an experimental drug that offered some promise if given within 72 hours of the injury. Like the movie Apollo 13, this was accomplished, but in 76 hours. However, though it seemed like an answer to their prayers, there was no assurance it would work in their son’s case. But it did! And 10 weeks later, he walked out of the hospital. Though doctors could not be sure it was a result of the drug, they admitted it was, as many view the rescue of Apollo 13, something of a miracle.

The second incident deals with the account of a daughter whose father is dying with cancer. She writes in hopes of encouraging others who must care for loved ones on the brink of eternity.

“Well… Apollo 13 has become my role model, my support, my comfort, and my favorite movie at 3 AM when I can’t sleep because I’m so overwhelmed with my own life. I’ve already written a review of Apollo 13 the movie. You can go look it up. I said it was great. I said you should watch it. But this isn’t just a review of the movie. This is about how I have emotionally connected with the movie. This is about how I use the movie as a crutch to get me through the day. This is about how Apollo 13 keeps me sane in an insane time!”

“They say that Apollo 13 was a Successful Failure because of all they learned from the experience. I’m hoping that my experience with cancer will also be a Successful Failure. The doctor has already told us that my dad won’t be cured and any treatments we do won’t change that. So I already know that I’m going to be a failure… Nothing I do can save my father’s life. But maybe I can learn and grow. Just maybe my dad and I can have some more good times together. Maybe we can have some fun and overcome some challenges on this journey. Then I’d say it would be a successful failure for sure. Sometimes I’m surprised at how my life seems to parallel the hardships the astronauts had to endure. I find myself doing things for my dad that I never imaged I would have to do.”

“The one line in Apollo 13 that echoes in my mind is Gene Kranz saying, “Failure is not an option!” I know that he meant they had to bring the astronauts back alive. I also know that my dad is dying and I can’t do anything to change that — except pray for a miracle. I am praying for a miracle, but I also know that I have to be prepared for my dad’s death. However, I still insist that FAILURE IS NOT AN OPTION! So, if death is inevitable — what do I mean? Well, I mean that whatever happens, I have to make sure I don’t give up. I don’t lose sight of the wonderful times we can still have. I don’t lose my humor or my love for life… I have to make sure that I do my best to make every day with my dad as wonderful as possible, that the end of his life is as good as it can be, and we learn something new every day we are together. I also need to remember that no matter how bad things get, I love my daddy and he loves me. If I just remember that… I can’t fail.”

Question from Terry G: With regard to the time constraints placed on the required engineering developments for the Apollo project, what was the greatest of the many engineering breakthrough that kept Apollo on track…which if any of the methods developed for Apollo’s lunar landings could we expect to see reused during the human space flight and landings on an asteroid and Mars?

Jerry Woodfill: The day you submitted this question, Nancy was drafting the best response I can think of – Lunar Orbit Rendezvous. Had America chosen the Direct Ascent Nova Class Rocket technique, I doubt if we would have succeeded in fulfilling President Kennedy’s challenge of reaching the Moon by 1970. Carefully read Account No. 12 in Nancy’s series of essays. It was the number one reason for our triumph!

As far as the second query, I’ll punt on that one, however, Google things like: Hohmann Transfer Orbit, Aldrin Cycler Orbit, and Libration Points. After reading about these techniques, you’ll be an expert on this kind of thing. Each summer, JSC has an event called THE SPACE SETTLEMENT CONTEST. I was one of the technical trainers, in robotics, for the high school students selected to attend. After doing Internet searches using the above search terms, I found a myriad of approaches exist, all having specific merits. Take a look at them. It’s a fascinating study.