Steve Bales: The Moon Landing’s Moment of Truth

Weather-wise, July 20, 1969 was a typical summer day in Houston: high temperatures, oppressive humidity and scattered thunderstorms. Inside NASA’s Mission Control operations complex, responsible for guiding Apollo 11’s crew to the first moon landing, the tension matched the weather. Mission Guidance Officer Steve Bales recalled, “I saw other members of the descent team coming on shift that morning, and no one, I mean no one, was smiling. The mood was tense and the air was heavy.”

Bales and his Mission Control colleagues were aware that day of the gathering storm of uncertainties and unknowns Neil Armstrong and Buzz Aldrin would face hours later. The Eagle, the Lunar Module, would undock from Columbia, the Command Module, and begin its historic attempt to land on the moon.

A 26 year old is put in charge

NASA Mission Control 1969 Soure: NASA

At 100 hours, 12 minutes into the flight, the Apollo 11 crew were given the “Go” for the moon. Armstrong and Aldrin undocked the Eagle. After a brief visual inspection, they began the powered descent to the moon.

For Bales, 26, this day seemed inconceivable just five years earlier when he graduated from Iowa State University with a degree in aeronautical engineering. Hired by NASA just months after graduation, Bales was assigned to Flight Dynamics, the critical function responsible for monitoring the spacecraft’s location and its guidance systems. The computers used for guidance were small and primitive compared to today’s smart phones, tablets and laptops. Bales said, “but they were the only thing we had to help us fly the spacecraft and get it to the moon.”

Bales worked his first mission as a flight controller for Gemini 10 when he was just 23. With the space program in its infancy, NASA had to ramp up staffing for Mission Control quickly, giving him and countless other young engineers the opportunity to be part of the ground-floor of a brand new organization. He said, “Everything was new: people, rockets and technology. We had to start with a blank slate and had to create procedures for every single system.”

For Apollo, the rocket itself encompassed over five-and-a-half million parts and complex systems that were managed and monitored by both the crew and NASA Mission Control engineers on the ground. Everything had to work flawlessly.

Simulations for every possible emergency

In order to ensure crew safety and mission success, volumes of mission rules were written and incorporated into simulations. These rigorous simulations were designed to prepare the crew and Mission Control to respond to virtually any scenario, from standard operating procedures to critical alarms, system failures and other potential emergencies.

One new rule would be that the Guidance Officer (or GUIDO for short) would have authority and responsibility for calling aborts. Bales said, “I was shocked. So with great apprehension, we went forward with the rule describing how the Guidance Officer could call descent aborts based on navigation errors from the spacecraft’s radars.”

The simulations for Apollo 11 began only three months before launch. Bales remembers, “They were thorough and they were intense. We worked on hundreds of contingency landing and entry issues, and it seemed like another hundred would pop up.” As Apollo 11’s July 16th launch date approached, Bales and other Mission Control colleagues hoped that many of the alarms they worked on, including the rule for descent abort, “would turn into mission rules which I thought we would never use.”

That new rule would become the defining moment in Bales’ NASA career.

The 12 longest minutes

Steve Bales Source: NASA

On July 20th, 1969 at 10:44 p.m. EDT, Flight Director Gene Kranz gave Armstrong and Aldrin the “go” to fire the Eagle’s decent engine. At the time, Eagle was 50,000 feet above the surface and 300 miles from the planned landing site. The next 12 minutes of the final landing phase would be critical.

Almost immediately Bales saw troubling data on his console. A downrange navigation error had the flight computer believe the spacecraft was descending 20 feet per second, 14 miles per hour faster than it was actually was. The abort limit was 35 feet per second, and if the error could not be corrected, Bales would have to make the call to stop the landing. Bales said, “from that point on, I was truthfully scared to death. I was mortified.”

Bales carefully monitored the data. Then suddenly, with about six minutes before touchdown, Armstrong and Aldrin saw the numbers “1202” flash on the lunar module’s navigation computer.

"Twelve-oh-two, twelve-oh-two," called Aldrin. Armstrong, in a tense voice, added, “Give us a reading on the twelve-oh-two program alarm.”

Again and again: Alarm Code 1202

Tension filled the “trench” of the Mission Control room, filled with rows of engineers managing all aspects of the different flight systems. Despite the exhaustive training, simulations and procedures governing Apollo 11, the 1202 alarm program was not familiar to the Flight Director or the other engineers in the room.

Except for one. Steve Bales.

“It was clear in their voices that the 1202 was causing the crew serious concern,” Bales remembered. But he and his support colleague Jack Garman had remembered encountering this very alarm during their three months of simulations. It meant that the navigation computer was receiving such a high volume of computational requests that it was prioritizing the tasks. “This triggered my memory. The rule was this alarm would be ok if it did not happen too often,” he added. Garman confirmed it.

The moon landing hung in the balance, resting on Bales’ shoulders.

Steve Bales – deciding in the eye of the storm

Since the data Bales was looking at was still good, he gave a loud „GO“ to Flight Director Gene Kranz and Capsule Communicator Charlie Duke, who heard it simultaneously. He added, “Usually the CapCom waits for the Flight Director to confirm it’s ok to pass anything to the crew. Charlie sensed it was critical that Mission Control was Go on the alarm, and he didn’t wait. He told the crew instantly.”

Two minutes later, Aldrin and Armstrong received another 1202 alarm, and once again Bales had to make the call. He quickly conferred with Garman again and then gave the “Go” to proceed with the landing.  The alarms were persistent. Bales said, “Forty seconds later a 1201 alarm flashed on the crew display and I responded ‘same type, we’re GO. Seconds later there was a 1202 followed shortly by another.”

Moon landing Source: NASA

The last 1202 occurred at an altitude of less than 1,000 feet. Despite the warning signals from the spacecraft’s radar and computers, a 26-year old and a 24-year old told the Flight Director and the two astronauts to ignore the confused computers and trust their assessment. By being able to ignore the alarms, Armstrong and Aldrin could concentrate on finding a safe landing spot.

Two minutes later and 240,000 miles away from Bales console at Mission Control, the voice of Neil Armstrong crackled through with man’s first words from another planet: "Houston, Tranquillity Base here. The Eagle has landed."