Put yourself in the situation of handling one-of-a-kind, (very!) expensive flight hardware, hardware that you know is going to Mars. Don’t let that affect you though, because it’s imperative that you have hands as steady as a surgeon. Fortunately, you have a detailed checklist of step-by-step assembly instructions, and occasionally you have to work under the watchful eye of a quality control engineer. For every step, you stop and check off what you’ve completed, because you must never skip any steps, or else you'll get no fabulous pictures of Mars for everybody back on Earth. You handle pieces that fit together so snugly that there's no gap wider than a tenth the thickness of a sheet of printer paper. Sometimes you have to put the screws in with tweezers. You solder the electronic components onto the boards by hand. Keep in mind that the junctures and boards you are building will need to handle thousands of days and nights on Mars, cycling between freezing at -100 degrees Celsius, warming up to highs of 15C, and going back to -100 again, every Martian day. There are hundreds of hardware components to assemble steadily, carefully, without tweaking or damaging any parts.

As we assemble the instrument, we do extensive testing of the individual components. As those are assembled into larger units called sub-assemblies and assemblies, those are also tested. That is eventually followed by an intensive battery of tests of the final integrated cameras, right before they are sent to NASA JPL. All this has to be done exactly right (preferably the first time). One way we prepared to assemble the precious flight instruments is to build an Engineering Qualification Model, as principal investigator Jim Bell described in a previous post. The EQM unit, as we call it, is designed and built identically to the Flight Unit (the one that will be sent to Mars).