"The Tumbleweed project had the highest potential giggle factor."

Interview with retired NASA employee Greg Hajos

Last week we had the honor to talk to Gregory Hajos, a now-retired NASA employee. He worked at NASA for 30 years and had a lot of interesting and fun stories to tell about his time working there. At NASA he also worked on Tumbleweed rovers more than 20 years ago and has decided to join us in recurring technical mentoring sessions to share his knowledge and help us on our journey. We are all very grateful for his generous support and I was very excited he took the time to have a virtual chat with me. It was extremely interesting to find out more about his work at NASA and his passion for space exploration.

When did you start being interested in space exploration?

I grew up in Huntsville, Alabama, which is where the Saturn rockets were developed, as well as the Redstone rockets, which launched the first American, Alan Shepard, into space. They were developed at the Redstone Arsenal and Marshall Space Flight Center, which are right next to Huntsville, Alabama. So, I grew up listening to rocket launches and rocket engine test firings. It was a normal thing that happened, not daily, but weekly or monthly, you could hear them test firing something. That spurred my interest. What really got me interested though, since that was an everyday thing to us, is what I see as the top quote of the 20th century: “Houston, Tranquility Base here. The Eagle has landed.” I was 9 years old when that happened.

"I grew up listening to rocket launches and rocket engine test firings."

What were your tasks and responsibilities at NASA?

As a co-op intern, I performed cost estimates for future projects. I used data from old missions to predict what the new missions were going to cost. After that, I transferred into the preliminary design office, where I was doing mechanical design. Working alongside an engineer with much experience and learning how to design. We were doing CAD, computer-aided design, back in the early 80s, when it was still fairly crude compared to today’s computer graphics.

Were these your responsibilities until you retired?

No, that was just one stop, I was working in structural and thermal design and analysis for a time and then I was back in mechanical design. We worked on the early phases of the design. We were program planning for future missions. That’s pretty much where I stayed till the mid-2000s. Then around 2006, I started working on flight projects. However, before that, I was working on future projects. It could be 10 to 15 years from the time we worked on it, did the pre-proposal, analysis, design work, and sent it off to the team that wrote the proposals to advance it to the next stage, to the actual launch. 10 to 15 years passed between that point and launch, for the ones that did launch. By the time they flew, I sometimes had forgotten about them. The total list of projects I worked on at NASA is about 130 and about 10% of those have flown. Then, in 2006 I joined the Ares IX launch vehicle program, rocket launch project, which was the flight project.

"It could be 10 to 15 years from the time we worked on it [...] to the actual launch."

How was it working on the Flight projects and how many launches were you part of?

It was different. Because before that you are working on something that you know is going to be reworked several times before it flies. Then, you’re working on something that is going to fly. Whatever design comes out of it, is what is going to be launched into space. It’s a different feeling. Yes, it was fun to work on future projects and predict what might happen in the future. Working on one that is going to fly, and is in process, where you’re seeing hardware build, it’s a different feeling, I don’t know how to describe the feeling. You put up with the 12-hour workdays 6 days a week and you just work your way through and keep going and keep going. Because you know something is coming of this.

I have been part of two launches, in terms of being there at the end of the design phase and going to the launch. Part of the launch team. That was exciting because you’re seeing the end product of what you’ve spent years working up to. In some cases years working up to this point. You’re reaching that point and you think, “There it goes and it works! That’s my baby going up into space. I was a part of that.”

What did you enjoy most about working at NASA?

What I enjoyed most was working on such a variety of different things, with people who were the top people in the world in their field. Sometimes they were the only people in the world working on that particular item and I was working alongside them. I learned so much. You think about going through college and getting your degrees and you know so much, but when you get out there working with these people you realize you’re still learning. You’re learning from them all of the time.

"Sometimes they were the only people in the world working on that particular item and I was working alongside them."

How did you start working on the Tumbleweed rovers?

The Tumbleweed project started out as a joke actually. It was right after the Pathfinder mission in 1997. We were in the break room sitting around and talking and we realized the Pathfinder traveled farther bouncing on its airbags than the Sojourner rover traveled in its entire month-long mission. So, we were joking about how we would get it to travel farther. “Well, it went farther on its airbags. Let’s try keeping the airbags rolling like a Tumbleweed.” We were joking and laughing about it. And then I said: “We can do that. I know how we can do that!” And then it took off from there. We found out shortly after starting there was a parallel Tumbleweed project at Jet Propulsion Laboratory (JPL) in California. They had created a tricycle-type rover with large inflatable airbags for the wheels. One wheel broke loose, and bounced across the Mojave desert. Once we found out about each other’s studies we combined efforts and started working together on things. Some of the parts I wish I would’ve gotten to go along with them. Frank Carsey and Alberto Behar got to launch their Tumbleweed in Greenland across the ice flow, and then they got to take it to Antarctica and launch it from the South Pole. That would’ve been exciting but that was theirs.

How long did you work on Tumbleweed Rovers and why did you stop working on them?

We worked on Tumbleweeds for about 6 years, on and off. We had other projects going too. We stopped because there was a high-priority program starting up and they needed people to work on that. The Tumbleweed project was a low-priority mission. The high-priority mission pulled a lot of people in and we were part of it. That’s pretty much why we stopped.

What were the biggest difficulties you and your team had while working on the Tumbleweed rovers?

For one, you always need funding to do the study. The Tumbleweed project was a low-level study. Technology readiness was very low, so funding was hard to get. Also, there’s explaining the concept to people. The hardest part was getting scientists to accept that they didn’t have to control every centimeter of travel. If you watch how the rovers travel on Mars, they go a short distance, they stop to look around and people on Earth send another message of where to go next. It’s a very slow process. They cover ground very slowly and very carefully. We were proposing an opposite to that – which was to travel long distances, then find out where you are, take measurements there and do your science at each location. It’s that release of control that was the hardest part.

"The hardest part was getting scientists to accept that they didn’t have to control every centimeter of travel."

From the top of your head, do you have one funny story about your work at NASA?

Not one, but several. The Tumbleweed is the one we had the most fun with. The Tumbleweed project had the highest potential giggle factor. People hear about it and they laugh. They giggle. “That’s so crazy”, but they stop and think about it and they think: ”We can do that”. There’s this stuff we’re working with that can help you. One good example of that was when we went to the advanced structures office to ask them about it. We told them we need to create a spherical structure 6 meters diameter at 10 kilograms or less and they said: “Well, we can do it in 5kg”. They laugh about the concept, but then say “We can do this, it’s doable.” Tumbleweed was fun because we were doing things that people were shocked about in a way. I would say the funniest to me was the Friday afternoon tumbleweed races. We would take fans outside our offices and race our prototype models in the hall. When our manager found out about it I heard him shout “They’re doing WHAT in the hallway?” We had a lot of fun with that.

Another way the Tumbleweed was fun is where we got our ideas. We watched a paper cup blow across the parking lot one day and said: “Oh let’s look into that”. We also actually bought a Tumbleweed from the Prairie Tumbleweed Farm. Which was kinda a joke in its own way. If you look up the history of the Prairie Tumbleweed Farm, it started out as a network joke. Someone learning how to create a webpage made up this fictitious farm selling tumbleweeds. They put it on the web and then people actually started ordering tumbleweeds from them, including us. So we put a real tumbleweed in the wind tunnel and got data from it and compared it to the models we had created.

We also gave talks to elementary school children, ages 5 to 10, which was also great. They are so open to new ideas. They would surprise us with some of the things they would do. We built models out of crafts materials. Styrofoam balls, pipe cleaners, paper cups, and so on.

"We were doing things that people were shocked about in a way."

What do you think the younger generation of scientists should lay their focus on regarding space exploration?

That is a large question. There are so many aspects to space exploration. It doesn’t have to be just the engineering of the mechanism or the electronics. What about the biological aspects? Everybody seems to be interested in what kind of life they might find out there. There is a good chance of it. But would we recognize it? We might not recognize it as something that’s alive at first. What about the mineralogical aspects of space exploration? That’s another important one. There are so many different aspects. The science developing, the propulsion system, the mechanical systems, the electrical system. Instrumentation is also a big one, designing the cameras and the different instruments to determine what materials there are. How do you get the samples? There’s so much that’s available that’s applicable to space exploration. Most fields have a place in space exploration. NASA is not just scientists and engineers of all fields, but also mathematicians, accountants, purchasing agents, artists, media specialists, computer programmers, managers, and many more.

What is your advice for young people interested in space exploration who want to pursue a career in this field?

Study and keep at it. Keep trying. Don’t give up. If you’re turned down the first time, don’t let that stop you. Try again. Maybe in a different area. In the USA NASA has 12 centers and there are also all of the contractors, the private industry that helps support NASA. Where you can work in the space program, you’re not a part of the government, you’re in the commercial part of it. There’s a lot of that out there. So just keep trying, you can get in.