The Brilliant Minds Behind Apollo Shine On

I wrote my memoir, The Step, to draw attention to the unsung heroes of the Apollo Program. The men and women who made up the technical team, instead of the astronauts who have historically received all the attention and the glory. I’ve been promoting my book and giving book talks for over a year now. I always mention the effort that was made to assemble this incredibly impressive, intelligent and hardworking scientific team that made this seemingly impossible feat, of landing a man on the moon, attainable. 

Last weekend I had the pleasure of addressing Mensa at their Annual Gathering in Hollywood, Florida. I ended my talk, as I usually do, with a Question & Answer session. One man named Bob Tewchuk raised his hand and asked, “Seems there is a rumor that 90% of the Apollo mission computer was code redundant. That is, 10% of the code contained the instructions, and 90% was used for error checking and to ensure there were no errors or crashes. A friend of mine told me this years ago, and I’d like to know if it’s true.”

I worked in PR not in computer programming, so I didn’t know the answer to his question. But I knew someone who would! I took down Bob’s information and promised I would get back to him with an answer. I forwarded his question to two of my former Apollo coworkers and friends, Kenneth Clark and Jim Handley. Here’s Ken’s reply:

“The term “code redundant” implies that there is code that is redundant for some reason such as to recompute a value for which the answer is known in order to verify correctness.  I doubt there was any of that in the flight computers and know for a fact there was none in the ground computers.  A second form might be some form of redundancy in hardware with identical software in the redundant hardware and some sort of voting logic to determine which hardware was correct.  The Launch Vehicle Digital Computer used triple modular redundancy (TMR) logic, but I don’t believe the code was replicated.  The Saturn Ground Launch Computers were not TMR.  However, the Mobile Launcher Computer did contain redundant set of code which was switched to if the primary memory encountered a parity error or no instruction alarm during execution.  I don’t know if the Apollo Guidance Computers contained any form of redundancy and don’t see any evidence of any in my investigation on the internet.

 On the subject of error checking, not even close to 90% of the code would be allocated to that task.  The amount of memory in any of the computers made it absolutely impossible for there to be much if any code in the computers to be used for error checking.  The error checking that existed was to determine if an operation requested or commanded by a program completed successfully.  There were some checks even in the Lunar Lander to report on unexpected errors.  An example of this was the Lunar Module program alarms minutes into the landing sequence (Error codes 1201 & 1202).

 Memory in the computers was mostly magnetic core.  Here are some examples of the memory sizes used in the computers

 Saturn Ground Launch Computers (RCA 110A) – 32 K 24 bit words + 1 parity bit

Instrument Unit Launch Vehicle  Digital Computer – 32 K 28 bit words including 2 parity bits

Apollo Guidance Computers — 2048 K words of erasable magnetic core memory and 36 K 16 bit words of read-only core rope memory.

 

Note:  There were 2 Apollo Guidance Computers in the spacecraft.  One in the Command Module and one in the Lunar Module.

 

Hope this helps,

Ken”

Amazing that over fifty years later his memory is so precise. I called him a genius in my book and clearly he’s living up to the title.

The remarkable triumphs of that team have changed the trajectory of our country forever. The greatest minds of the time collected and working together were ever so powerful. Unfortunately, when Apollo ended the team was disbanded. Many of the brilliant scientists and engineers were sent packing or to sell typewriters.

Our space program has been stuck on the back shelf for years. As we stagnate China, Russia and private companies make leaps and bounds forward. It’s about time we revisit our treatment of the space program and recognize it’s importance in securing our future stability and respectability as a nation. I can think of two guys who would be perfect to head up the scientific team!

You’ve Come a Long Way Baby…

Martha and IBMersI am reminded of a date in time: August 26, 1971. I was working at Kennedy Space Center (KSC) as a member of the Apollo Launch Support Team. At the behest of Rep. Bella Abzug (D-NY) Congress designated August 26 as “Women’s Equality Day.”

Thus began a massive, peaceful civil rights movement by women that had its formal beginnings in 1848 at the world’s first women’s rights convention in Seneca Falls, New York.

The observance of Women’s Equality Day not only commemorates the passage of the 19th Amendment, but also calls attention to women’s continuing efforts to gain full equality.

I had endured my own challenges in the 60’s and 70’s regarding women’s rights. Following my divorce, I couldn’t obtain a checking account unless my ex-husband signed for me. The very clothes I wore in performing my job as a writer at KSC were designated “safety hazards.”

I was also making much less money than my male counterparts as a PR writer. Yet, I knew that things would change; after all I worked for a very progressive company, IBM.

Betty Friedan’s international bestseller, “The Feminine Mystique” ignited my personal consciousness to what gender equality should mean in America and around the world.

Friedan challenged the assumption, at work and at home, that women should always be the ones who make the coffee, watch over the children, pick up after men and serve the meals.

On my own personal level, after years of proving myself and finally being promoted from secretary to write, I recall with great pleasure that same day that I refused to get coffee.

I was a workingwoman when women did not work outside the home. Some of my children’s friends were not allowed to even come to our home, because I wasn’t there to supervise.

Today, it’s common for both the husband and wife to work. Despite the increased workload of families, and even though 70 percent of American children now live in households where every adult in the home is employed, no major federal initiative to help workers accommodate their family and work demands have been passed.

Today, women are still paid less than men at almost every educational level and in almost every job category; they are less likely than men to hold jobs that offer flexibility or family-friendly benefits. When they become mothers, they face more scrutiny and prejudice on the job than fathers do.

We need to stop seeing work-family policy as a woman’s issue and start seeing it as a human rights issue that affects parents, children, partners, singles and elders.

Yes…we have come quite a way in gender equality since the 60’s and 70’s…but Baby, we’ve still got a long way to go!

 

Martha Lemasters is the author of “The Step…One Woman’s Journey to finding her own happiness and success during the Apollo Program.” She resides in Vero Beach FL and has a summer home in the Highlands area.