You Never Forget Your First

or

Important Lessons I Learned Early in My Engineering Career

By

Johnathan W. Carson

Originally published August 2026

The very first flight mechanism I ever designed was for a mission called IPEX-II.  I was only about a year and a half—maybe two—out of school at the time, and this felt like such a great opportunity.  I was part of a very small team, and we had a ridiculously short schedule.  We had just nine months to go from a blank sheet of paper to fully tested flight hardware.  Looking back, I'm still amazed we pulled it off.

The mission was a science demonstration to measure the on-orbit disturbances, the snap, crackle, and pop, of a deployable carbon fiber truss as it passed into and out of direct sunlight during each orbit.  The truss itself was a nine-bay version of the then-new ADAM mast, produced by AEC ABLE, and was being considered for several future flight projects.  One of those was the Space Interferometer Mission (SIM), where the microdynamic behavior of the deployed structure was of particular concern.  

IPEX-II on orbit aboard CRISTA-SPAS during STS-85. The nine-bay ADAM mast is visible along the left side of the spacecraft. Credit: NASA.

While the mast was designed to be deployable once in orbit, for this mission the project chose to leave that extra hardware behind and launch the truss in its final deployed state.  That meant a launch latch was needed, and that was now my job.  The spacecraft was a free flyer, but it went up—and, more importantly, came back down—on the Space Shuttle.  That meant man-rated, which added an entirely new level of complexity to what was already going to be a challenge because of the schedule.  

There were two key requirements that drove the whole design. The latch had to be two-fault-tolerant when returning to its safe position, meaning any two components of the mechanism could fail, and it still had to be able to successfully relatch the mast. It also had to return to that safe position automatically in the event of a power loss. Failure to deploy would mean losing the experiment; failure to relatch could put the Shuttle—and therefore the astronauts—at risk. Those requirements drove a great deal of redundancy into the design.   

CRISTA-SPAS being integrated with the Space Shuttle payload bay. Safe retrieval and relatching were mandatory before the spacecraft could return to Earth.

While this was a small team, I was not working alone.  Don Moore was brought on to be my analyst, and Jeff Umland, whom I reported directly to, was very involved in the systems side.  Both Don and Jeff were available to help me work through design issues, and I took full advantage of that, but I was left to make my own decisions about how to best design this latch mechanism.  Don was my guardrail.  He made sure I didn’t do anything catastrophic.  He did make suggestions from time to time, but it must have been difficult for him to let me build this when I’m sure he could have done much better.  Of course, had he done that, I wouldn’t have learned anywhere near as much.  I now understand how much restraint that requires of a mentor, and I appreciate it all the more today.    

The mechanism I ended up with met all the requirements, and technically it worked well.  It functioned exactly as designed, and the mission was a success.  I even received a JPL NOVA Award for innovation for that latch. It was extremely overweight, however, and much more complicated than it really needed to be.  The latch consisted of a plunger driven by three springs.  These springs forced that plunger to engage with and firmly secure the truss unless the latch was actively driven open.  That was accomplished through a variant of the Dual Drive Actuator developed by Doug Packard several years earlier.  Other components used were a ball screw, wax pellet actuator, a pair of drive gears, many different flexures, roller bearings, limit switches, and an energy absorber.  This was all added to ensure we met the two-fault-tolerance requirement and that the latch would return to safe without command or power.  It was somewhat Rube Goldberg-esque.  

IPEX-II during ground integration. My launch latch is the exposed cylindrical mechanism near the top center of the spacecraft, shown here with its rear cover removed. 

At the time, I had an inkling of an idea of how to do that latch much better, but I just couldn’t bring it into focus.  It was almost like I could see a couple of details, but the rest of it was enshrouded in fog.  Today, that alternate method is crystal clear in my mind, and it is absolutely the way I would approach this device now.  Back then my toolbox was pretty sparse.  Today, that toolbox is stuffed to the gills.  

When I think back to this mechanism today, I’m both a little proud and a little embarrassed.  Proud because we achieved this in record time, and it worked.  Embarrassed because it was very clunky, and I could do so much better now.  Then I think to myself, “I won an award for that piece of crap!”

Now, it’s not exactly fair to compare the 20-something-year-old me to the me of today.  I have decades more experience than I did back then.  And it's no more fair for a young engineer today to compare themselves to someone with decades more experience. Don't be intimidated by that experience. Take advantage of it. Study their designs. Ask why they made the choices they did. That's how you start filling your own toolbox. 

In addition to adding a lot of experience and a few tools to that toolbox, I learned three very important lessons from Jeff.  One I took to heart immediately and used frequently ever since.  The second took a lot longer to develop, but I continued to use and refine it throughout my career.  The third I did not appreciate until several years later, when the importance of that lesson hit home hard.  

I learned that first lesson while assembling and testing the latch mechanism with Jeff.  I had just finished putting together the wax pellet and limit switch assembly.  I then proceeded to apply power and test it.  Jeff was across the room, working on something else.  The test was successful, and I expressed my relief and happiness to him.  That’s when he turned to me and said he was happy it worked, but that I should never work in a vacuum!  He pointed out that I should have involved him in the test.  He would have been valuable as an observer and could have helped ensure that I didn’t overlook anything.  He was, of course, correct, and I immediately felt like a fool.  I adopted that lesson on the spot and have carried it with me ever since.  I frequently ask others to verify my assumptions, review certain aspects of my work, or just check my math.  

Another engineer isn't there merely to approve what you've done. They're another set of eyes. They may notice the thing you're not looking at because you're concentrating on something else. And having somebody challenge your assumptions before the hardware challenges them is generally cheaper.

The second lesson was more subtle, but no less important.  We were near delivery, and I was running a little late.  I don’t remember exactly how these events took place, but it was something like this:  Jeff came to my office for a status update.  I told him about the problems I was having but that I was working through it.  He then said something like he wasn’t sure if he should use the carrot or the stick, but he decided that the carrot was the right call this time.  Now keep in mind that we had been working long hours for weeks at this point.  I was regularly putting in 12- to even 16-hour days, and I was getting a little punchy.  I said something to Jeff like he made the right call, and if he had chosen the stick, I was likely to break it in two and shove it somewhere he wouldn’t like.  It was at that moment that I realized the importance of knowing when to push and when to help.  Granted, I spent years working to develop that skill, and I’m still not an expert, but it was a very important lesson to learn.  

The last lesson came after delivery.  Jeff made a comment about the importance of having a champion at JPL.  Unfortunately, I didn’t appreciate the truth of that statement until much later.  I foolishly thought that if I worked hard and demonstrated good engineering, my skills would stand on their own.  Oh, was I wrong!  You can do an amazing job, but if the right people don’t know about it, you won't build a reputation for that kind of work, and you won’t get the interesting jobs.  All that hard work just sort of fades away.  

Unfortunately, good work doesn't actually speak for itself.  People speak for it.  Someone has to know what you did, understand why it mattered, and communicate that to people who weren't there. That's especially true in a place full of talented people solving difficult problems. Upper management can't personally see everybody's contributions.  That doesn't necessarily mean office politics or shameless self-promotion. It means that having respected people who know your work—and are willing to advocate for you—matters.  When the right people know what you’re capable of, you’ll start to get those more difficult assignments, have greater responsibility, or simply have somebody take a chance on you, just as Jeff did with me so many years ago.  

Looking back, there was another part of that lesson I didn't understand at the time. I should have done a better job of maintaining my relationship with Jeff. As the years passed, we would occasionally cross paths, but I sometimes felt as though I might be bothering him, so I rarely made an effort to reach out. I never really knew if that was true because I never asked. I wish I had. Good professional relationships, like any others, need a little tending. If someone has taken an interest in you and your career, don't simply assume they're too busy to hear from you. Stay in touch. 

I certainly wouldn't design that latch the same way today. Given the chance, I'd throw all of it away and start over. I’d almost certainly use an over-center linkage, driven by a small spring, to trap that mast.  But I wouldn't trade the experience of designing it for anything. The experience of designing that overweight, overly complicated mechanism added some very useful tools to a sparse toolbox that I've been filling ever since. More importantly, Don and Jeff taught me lessons during those nine months that I carried with me for the rest of my career.

Your first few designs probably won't be your best work. In fact, I certainly hope they aren't. If you're still designing things the same way decades later, you haven't learned very much along the way.

So yes, when I look at that latch today, I still shake my head at how complicated it was. I can see a much simpler solution now that I couldn't quite see then. But maybe I shouldn't be quite so hard on that young engineer. He had a small toolbox, a brutal schedule, and a very difficult set of requirements. In the end, the damn thing worked.

And apparently somebody thought it deserved an award.

Lessons I Took With Me

• Don’t work in a vacuum.
  Another set of eyes can catch what you miss, question your assumptions, and keep small mistakes from becoming expensive ones.

• Know when to push and when to help.
  Good leadership isn't always about applying more pressure. Sometimes the person who's struggling needs support, not a bigger stick.

• Good work doesn’t speak for itself. People speak for it.
  Find people who know your work, understand its value, and are willing to advocate for you. Value those relationships and make an effort to maintain them.  And as you become more experienced, do the same for others. 

• Fill your toolbox.
  Study how experienced engineers solve problems.  Ask why they made the choices they did.  Every design—especially the imperfect ones—adds another tool.

Explore Further

IPEX-II and the ADAM Mast  

ADAM Mast Design and Behavior

Space Interferometry Mission (SIM)

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