The Caretaker

An aerospace engineer finds a second career tending to NASA’s retired space shuttle orbiters.

Dennis Jenkins wanted to retire early. For most of his career, he worked as an engineer for contractors assigned to NASA’s space shuttle program. He was 54 when NASA stopped flying its shuttle fleet in 2011, and he planned on retiring the next year, after overseeing delivery of the four retired orbiters to their new homes. (Discovery is on display at the National Air and Space Museum’s Steven F. Udvar-Hazy Center in Virginia; Atlantis is at the Kennedy Space Center Visitor Complex in Florida; Enterprise is an exhibit at the Intrepid Sea, Air, & Space Museum in New York City; and Endeavour belongs to the California Science Center in Los Angeles.) Some 10 years later, Jenkins is still working with the shuttles, relying on his expertise in orbiter construction to ensure their maintenance as museum artifacts. Jenkins recently spoke with Air & Space Quarterly senior editor Diane Tedeschi.

How did you get your current job?

I worked on the shuttle for 33 years. For my last job on the program, I was the project manager who supervised the delivery of all the retired orbiters to the museums. I sort of stuck around and helped each museum with its display. And now if something goes wrong with a shuttle, I’m the guy they call.

What did you do before you started working on the shuttle program?

I was training to be a U.S. Army helicopter pilot. It was right after Vietnam. In fact, I enlisted while Vietnam was still going on. By the time I got into flight school, they decided they had too many pilots. So I went back to school and became an engineer.

What did you study in college?

I’m an aerospace engineer for my bachelor’s and a systems management grad for my master’s.

Do you service all four orbiters?

I’m the project director on Endeavour [to be displayed in a new exhibit that opens in 2025 at the California Science Center], so I’m in Endeavour constantly. That’s sort of my day gig. Atlantis and Discovery, we do periodic inspections of. I don’t personally inspect Enterprise, but I arrange to have it inspected.

What is required to transition an orbiter from a working spacecraft to a museum display?

When the orbiters were still operational, they had about 400 pieces of ordnance on them. Small explosive bolts, explosive nuts, and explosive cord that separated windows and various components. When we retired them, we had to remove all the explosives. That was probably the biggest job.

The second biggest was the reaction control system: The little thrusters that let us maneuver in space were all powered by hypergolic propellants. They are extremely hazardous—very carcinogenic and dangerous to humans. So we had to go in and remove anything that had ever touched a hypergolic propellant—all the lines, the engines, the tanks. Then there were things that were dynamically dangerous: components that had spring tension. We had to go in and disable all the springs so they wouldn’t hurt someone who inadvertently activated them. While making the orbiters safe, we tried to do it in a way that wouldn’t be obvious to museum visitors. And we wanted future historians to have a vehicle that was as close as possible to what had actually flown in space—without being hazardous.

What is involved in your inspection of Discovery? Is it a nose-to-tail affair or are there just a few places you need to examine?

Four or five years ago, we noticed a hydraulic leak on Endeavour, and when we went into the aft compartment—where the main engines used to be—we found a temporary hose that had been connected for the delivery flights that was not meant to be there forever. And it was beginning to leak. Since we found it on Endeavour, we talked to the Atlantis and Discovery teams, and both wanted us to do inspections to make sure the hose wasn’t leaking on those vehicles. It turned out that it was leaking on both Discovery and Atlantis. So we removed the hoses and we capped the lines.

The inspection of Discovery this year is primarily just looking at the hydraulic leak to make sure we really fixed it. When we inspected it last year, we found there was another small hydraulic leak that was unrelated, and we fixed that one too. The inspection also gives us another opportunity to clean up the hydraulic fluid. An orbiter’s aft compartment has numerous wiring and tubing bundles; they’re so closely spaced that the fluid just sits on them, and you can’t really reach in to clean them.

You have to wait for the fluid to slowly drip down. You don’t want hydraulic fluid pooling there long-term because it’s corrosive. It could eat into the vehicle, so we’ll go in with the help of the [National Air and Space Museum’s] curatorial staff and the collections staff and clean it up, make sure it’s good. We may have to do one more visit depending on how much hydraulic fluid we find. It might be an annual thing for a while, which is fine. My team and I love coming up here and working with everybody.

What tools do you use for these inspections?

Surprisingly few. We have to remove a large hatch—it’s a strange rectangular-shaped door on the aft fuselage. It’s held in by probably 80 or 90 fasteners. They’re simple Allen-wrench fasteners. We do not use power tools on space shuttles. That means you’re basically working with an Allen wrench to remove these 80 or 90 fasteners. A bit tedious, but it ensures you don’t damage anything. That’s really the only tool we use for this inspection. Other than that, it’ll be cleaners and rags and things to mop hydraulic fluid and of course flashlights and ladders to gain access.

So the job requires some physical effort.

It sure does. That hatch probably weighs a hundred pounds or so, and it’s awkwardly positioned. It takes at least two people to do it—three people are better. I almost always bring one of my engineers to assist with an inspection.

What are the challenges in keeping these artifacts preserved for future generations?

They’re essentially airplanes, so taking care of them like an airplane is all they really require. They’re aluminum, so they don’t want humidity—they don’t want to be rained on. The tiles and the blankets that cover them—the thermal protection system—are extremely fragile. If it gets bumped, it breaks. I mean, literally, if you just tap your finger on a tile, it will break the surface of the extremely thin glass coating. When cleaning crews dust the tiles, they use soft mops. Initially, all the sites were extremely reluctant to dust the orbiters because they were afraid of breaking the tiles.

What would it take to make Discovery space worthy once again?

It would be impossible. There was a movie last year, Moonfall, about that very premise—except it featured Endeavour. But what was possible on film wouldn’t be feasible in real life. The orbiters have no engines. They have no reaction controls. You would have to remanufacture all of that. The only external fuel tank that exists is in California, and it’s not truly flight worthy. You’d have to set up a production line for external tanks, which would be prohibitively expensive. As for the solid rocket boosters, Artemis is using the same ones, so those are actually available. But there are no launch sites available. Of the ones at the Kennedy Space Center in Florida, one of them was turned over to Elon Musk for his Falcon program and the other one is being used for Artemis. There’s also no software production facility for the shuttle.

Do you have a favorite orbiter?

Because it was the first orbiter I was in, it would be Enterprise. I was 18 at the time, and Enterprise was just being built. I was fortunate enough to be able to go inside her when she was in the factory. So Enterprise is my favorite, even though she never flew in space.

Tell me more about your work with Endeavour in Los Angeles.

We’re building a new facility called the Samuel Oschin Air and Space Center to house her. She’s going to be displayed in a launch configuration, so she’s going to be vertical—with an external tank and two solid rocket boosters. It’s a huge building because you need to be far enough back to be able to see everything. I’m the project director, so I’m in charge of everything. I’m overseeing the construction of the building and stacking the vehicle. It’s really all I’ve been doing for the last 10 years. We’ll open the new building in late 2025.

As far as delivering the orbiters, which of the moves was the most nerve-wracking?

Discovery was the most nerve-wracking in many ways because it was the first time this particular crew had ever used cranes to remove an orbiter from the back of a 747, as opposed to the specialized infrastructure that we normally used. It had been done before, so we knew it was possible, but nobody on our team had done it. We were very nervous. Of course it decided to pour rain while we were trying to do it, which only made the job more difficult. With Endeavour, we had to move it 13 miles through the streets of Los Angeles to get it to its final location. It was a harrowing three nights and three days of moving, which thankfully went off without a hitch. Coming up, the most nerve-wracking piece will take place this September when we try stacking Endeavour with cranes. We’ve never used cranes to stack an orbiter before. That will be the hardest piece of all the moves. 

This article is from the Spring issue of Air & Space Quarterly, the National Air and Space Museum's signature magazine that explores topics in aviation and space, from the earliest moments of flight to today. Explore the full issue.

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