The weakest points of a cleanroom, where contamination is most likely to originate, are the points at which people and equipment enter and exit the controlled area.
There are various technologies available to limit the potential risk, including airlocks, pass-throughs, autoclaves that operate through the wall and air pressure differentials.
This is fine when the cleanroom is handling relatively small items that can be transferred in and out on trays, trolleys or pallets. But what if you are assembling a spacecraft and a conventional cleanroom simply won’t fit the bill because the project is being carried out in a massive hangar and many of the components have to be craned into place from above?
This is the kind of exercise in lateral thinking you might expect to come across in an advanced physics exam, but it was a real conundrum facing NASA in the preparation for launch of the Orion spacecraft. The answer, it seems, is to build the cleanroom around the craft and leave it without a ceiling. This innovative project is currently undergoing final testing.
Nor is this the only example of a challenge to the traditional concept of a cleanroom. The new Rainbow Process for image processing incorporates its own in-built clean environment, which saves not only the expense of operating a full cleanroom, but also involves a low-energy process and occupies a small footprint.
In a world where technology is changing at a breathtaking rate it is good to see new cleanroom concepts and new product developments meeting industry challenges.