Major 7V space chamber facility upgrade underway
By Philip Lorenz III
/ Published May 16, 2007
ARNOLD AFB, TENN --
A major upgrade to Arnold Engineering Development Center's (AEDC) 7V space chamber facility is underway.
Demolition on the chamber's clean room began April 4, as part of a major upgrade project. The 7V chamber has been the primary sensor calibration facility at AEDC since the early 1970s.
Significant performance and capability upgrades to the facility were completed in March 1994, resulting in an advanced capability for the next generation of seeker and surveillance sensors.
The 7V chamber is a deep space simulation test facility designed to test surveillance, airborne, and interceptor sensors. According to 7V Project Manager John Humphries, the upgrade project, valued at close to $800,000, will bring the facility up to 21st-century standards.
"The goal is to make sure we have a new, essentially 21st century clean room to offer to our customers," he said. "This will result in an improved clean room environment, which is critical for protecting the customer's test article and the facility hardware. The new clean room will provide a much more consistently controlled environment."
Explaining the significance of a modern clean room, Humphries said, "The biggest reason for a clean room is environmental control to maintain temperature, relative humidity, and particle control for the sensor and test chamber. It is absolutely critical that the test article is kept clean - particles or surface contamination on an optical element can corrupt the sensors ability to collect and process images. Cleanliness is a huge issue, and once you get the (test article or optical equipment) dirty, it's very difficult to clean it again."
Upon the project's completion, the 7V space chamber will have an overall class 1,000 clean room.
"A class 1,000 clean room means that you have no more than 1,000 particles per cubic foot that are 0.5 microns in size or larger," he said. "For reference, that's one two-hundredth of a human hair in diameter."
The contract for the project, which was awarded last September, went to Western Environmental Corp. out of Franklin, Ohio. The company has a team of 15 to 22 people on-site to do the work. Humphries characterized the type of work being done as an upgrade and repair project.
"They are demolishing the old clean room and will actually build the new one around the chamber," he said. "The new clean room will be larger and the team will construct the walls of composite materials. Also, they will be changing the airflow from a horizontal to a vertical flow."
Humphries explained the reason for the airflow change, saying, "The big thing regarding the airflow is the number of filter units that are used - instead of having them on both sides, we've found we get much cleaner air by pulling it in from overhead, pushing it down and drawing it back in through the walls. The walls are actually the return ducts in the system. It's a more efficient system."
Test and Operations Engineer Josh Drumm, added, "We've also found that the horizontal cross flow of air across the chamber, which is sitting in the middle of the room, has dead spots with little or no airflow. You want to keep a uniform flow across the test article and the chamber. The flow needs to be a continuous sweeping action which pushes (dust) particles down and back through the return ducts. You are taking it (the air) from a plenum area above the clean room and pushing the air back through the filtering system, which continually moves and forces particulate matter out of the air."
Humphries said the subcontractor has tentatively targeted completing the 7V Space Chamber upgrade project by mid to late August.
"This project will give Arnold Air Force Base an opportunity to present itself to other customers with a true state-of-the-art clean room," he said. "A facility like 7V is a huge attraction to potential customers. This upgrade will give them a real viable opportunity to do testing without having to build their own chamber in a clean room environment. You can imagine if they had to build the chamber and all the associated support equipment - the plumbing, the electrical, the data systems - everything that goes with it - it would be a huge undertaking."