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Spokane, Washington  Est. May 19, 1883

This former SFCC computer science professor worked on Ranger, Surveyor moon exploration missions

Don Willingham's early career was as a scientist at Jet Propulsion laboratory designing instruments to ride on early space probes to the moon, specifically the Ranger probes and Surveyor soft landing probes. On the table is an original print of a a photo of the lunar surface, which mapped parts of the moon used to plan the manned missions to the moon.  (Jesse Tinsley/The Spokesman-Review)
By Mathew Callaghan The Spokesman-Review

“That’s one small step for a man, one giant leap for mankind” echoed around the world on July 20, 1969, when Neil Armstrong famously stepped onto the moon for the first time.

But before Armstrong, scientists from around the country had set to work on the unmanned Ranger and Surveyor projects with the purpose of learning more about our cosmic companion.

Donald Willingham, one of the scientists who worked on the Ranger, Surveyor and eventually Pioneer missions, now lives in Spokane and was a computer science teacher at Spokane Falls Community College for 20 years.

Thomas Rindfleisch, who worked alongside Willingham for Rangers 6 through 9, helped create the first digital image processing that became crucial to the success of the Ranger and Surveyor missions.

With the Artemis mission’s first launch coming Monday, the two men talked about their 1960s work on space missions designed to ultimately put men on the moon.

“The Ranger mission was a complex system to launch, navigate to the moon, and operate scientifically to get optimal photographs, scientific and engineering data,” Rindfleisch wrote in an email.

The data gathered from the Ranger mission would help scientists better understand the moon, and help pinpoint a location for the upcoming Apollo missions to land.

The Ranger mission, unlike Surveyor, was only meant to take pictures of the moon for a brief span before violently crash landing on the surface of the moon. The pictures would have to be transmitted back to Earth just in time.

Willingham, 85, has a kind smile and a jolly laugh when he reflects on his life, including his time studying at Purdue University, working at the Jet Propulsion Laboratory, and eventually his journey to Spokane, where he met his wife at the Unitarian Universalist Church.

The excitement began when Willingham was assigned two years of active duty in the Army after graduating with a degree in engineering physics from Purdue in 1962.

The JPL in Pasadena, California, took note of Willingham’s degree and intellect, and asked if the Army would let him spend his two years of active duty at the lab.

Once there, Willingham was assigned to the Space Sciences Division, where he worked on the development and deployment of the TV photography Ranger missions to the moon. Willingham said he was chosen to work in the photography department because he knew nothing about photography. Willingham’s boss, Ed Dobies, wanted someone with “no preconceived notions.” Willingham described it as turning a television camera into a scientific instrument.

Willingham’s job title effectively became Cognizant Scientist for the Ranger TV Mission. Willingham humorously said, “Cognizant probably meant that we stayed awake during meetings.”

It was during his time as a Cognizant Scientist that Willingham worked with scientific visionaries such as Gerard Kuiper, director of astronomy at the University of Arizona; Harold Urey , Nobel Peace prize recipient for the discovery of heavy water; Gene Shoemaker , director of Flagstaff U.S. Geological Survey and Planetary Geology); and others. Willingham describes these men as “eminent scientists.”

The Ranger missions were divided into three blocks. Block 1 included Rangers 1 and 2. Block 2 included Rangers 3, 4 and 5. Block 3 included Rangers 6, 7, 8 and 9.

Each block had slightly different mission objectives, and each had progressively more advanced system designs. By the time Willingham got to JPL, Ranger 1 and Ranger 2 had already failed because of their inability to leave low-Earth orbit.

Willingham said shortly after beginning work at JPL, he discovered Russian astronomical measurements of lunar brightness that would help him develop a lunar reflectivity model. This model would be important because it would give scientists the ability to “predict the brightness of the lunar surface as a function of incidence, emission and phase angle.”

When attempting to find a place for future manned missions to land, every aspect of the lunar surface was important.

Unfortunately for Willingham and other scientists working on the Ranger missions, the next three missions proved unsuccessful. These three Rangers had payloads that consisted of one crude TV camera and several science experiments.

“The Air Force came in at the last minute, on Rangers 3 through 5, and said, ‘Oh, you have to cut the payload way down,’ ” Willingham said. “So we had to cut out instruments, and they cut out the redundancy and the electronics. And in the long run, that’s what caused most of the errors, plus their rockets didn’t work worth a damn initially.”

During this time, Rindfleisch was hired to help Willingham. To this day, both men speak highly of one another.

Rindfleisch described Willingham as “very smart, patient, innovative and rigorous.”

For Rangers 6 through 9, only camera systems were on board. Camera A was for big areas, Camera B was for areas one-third the size of the first camera, and four cameras, called P cameras, were for small areas. The Ranger missions had about 23 minutes to take pictures of the moon before it crashed onto the lunar surface. Willingham said after a year hiatus, Ranger 6 was ready and different from the previous Ranger blocks.

“It wasn’t at all the same payload, but there originally were science instruments on, but they threw all those off, and then got the redundancy back in the electronics and everything. So everything was gonna be perfect and Ranger 6 went up right where it was supposed to. But Cameras never turned on,” Willingham said, recalling the uncertainty and disappointment he felt from another failure.

Willingham became concerned about job security. Even though JPL had “moved aside a couple of the head guys,” it was known that if the next Ranger mission failed, JPL was going to start firing people at the top and then work their way down.

Rindfleisch described some of the work he and Willingham did on the Ranger project:

“He (Willingham) was working with the television camera engineers on Ranger and got me interested in where it would be best to impact the spacecraft relative to the terminator (division between night and day on the moon),” Rindfleisch said. “We developed a Figure of Merit to measure system resolution, taking into account camera resolution and light sensitivity, surface feature contrast owing to sun incidence angle, electronic signal to noise ratios, image motion, etc. He also did the initial research to find important publications by a Russian astronomer that documented the surface reflectivity properties of the moon that I used in the topographic map development work (mentioned above). All told, he was the first professional engineer that served as a role model for how to approach practical research problems. I published my first scientific reports and papers with Don.”

Finally, after a lot of hard work from everyone at JPL and NASA, Ranger 7 was successful. Following many trials, it seemed the scientists’ labors finally blossomed. When asked what made Ranger 7 work, Rindfleisch said, “Probably luck as much as anything.”

During the final 17 minutes of flight, Ranger 7 sent 4,300 pictures from six cameras back to Earth.

Ranger 8 took more than 7,000 images and even identified an area for Apollo 11 to land.

Ranger 9 captured 5,800 pictures and reinforced conclusions scientists had reached after previous Ranger missions. The success of these three missions gave JPL and NASA a close look at the lunar surface and lit the fire that would lead to man’s first moon exploration.

Willingham said that 199 pictures and 300 copies of those images gathered from the Ranger missions were sent to embassies around the world as a peace offering, despite the ongoing Space Race with the former Soviet Union. When asked if that competition had an effect on his projects, Willingham responded: “Oh hell, yes! That was the whole impetus for the whole thing.”

Although pictures of the moon were great, there wasn’t yet enough evidence to warrant a manned mission to the moon.

This led to the Surveyor projects. Although the conception of Surveyor came around the same time as Ranger, development began in 1961. In June 1966, Surveyor 1 became the first spacecraft to soft land on the moon.

Surveyor had a different mission, launch vehicle and, according to Willingham, a different way of developing. Willingham’s title transferred to Space Sciences Mission Analyst for the Surveyor project.

Willingham described the difference between the Ranger and Surveyor missions as night and day.

To Willingham, Surveyor was much more sophisticated, as it had the unique ability to perform a soft landing on the surface of the moon.

“The surveyor had a camera when it soft landed, and that’s how you got all those pictures. But it had the ability to dig a trench (to gather samples). And yeah, it had several instruments on board.”

Willingham said the engineering people who were involved in the Surveyor project were extremely talented, given how quickly they created a spacecraft capable of soft landing. The Surveyors’ ability to take pictures, gather samples and data all while bolstering the ability of soft landing was revolutionary. Apart from improved technical abilities, Willingham says the Surveyor’s management structure was better than the Ranger project.

After Surveyor 1, Surveyor 3, 5, 6 and 7 were all successful. Surveyor 2 crashed into the moon, while Surveyor 4 lost signal 2½ minutes after landing.

In total, 90,000 images from five sites and many more analyzed lunar elements made the Surveyor project a wildly successful endeavor.

That success reassured astronauts and scientists that the moon was safe to land on. Shortly after the last Surveyor mission, the manned Apollo missions arrived on the moon.

In November 1969, astronauts aboard Apollo 12 landed near Surveyor 3. The astronauts took pictures and even took parts, including the scoop of the Surveyor, back to Earth.

After the Surveyor and Ranger missions, Willingham worked on a small instrument that went on Pioneer 10 and 11. This instrument was called an ultraviolet photometer.

“As the sun gives off all these particles, and as a particle cools, the electronic orbits will drop,” Willingham said. “And when the orbit drops the individual atom gives off a photon of light. OK, individual pulse of light, and they are different colors. What this one (ultraviolet photometer) detected, was the color of hydrogen and helium. What it (the instrument) did is it measured the ratio between hydrogen and helium. For some reason, that was important.”

Pioneer 10 returned signals back to Earth for 35 years. Pioneer 11 worked for 22 years. The Pioneer missions took pictures and gathered data from our neighboring planets, Saturn and Jupiter. The Pioneer project also paved the way for future spacecraft missions, like the Voyager, Cassini and Galileo missions.

Today, Willingham said he is lucky to always work somewhere he loved, whether it’s working on spacecraft or teaching at SFCC.

“I was able to have the total experience,” Willingham said. “I think that’s the big thing. Was having that total experience, you know? One of the things that I really learned is, you can always find someone smarter than you.

“A genius worked for me, and I worked under a genius.”

Despite all of his work in space travel, Willingham said his best experience was coming to Spokane in 1972 and later meeting Elva Miesch, who he married in 1977. She died in 2012.

“Well, this lady that I was married to for 35 years was out of this world,” Willingham said, “Just out of this world.”