Guest Bloggers: Jason Hair, Dennis Reuter, and Amy Simon
Building a mission or an instrument is not for the faint of heart. While engineering teams develop plans to avoid major mishaps, sometimes even the best laid plans aren’t enough. A case in point is a series of unfortunate events that happened to the OVIRS instrument in July 2014.
OVIRS is a spectrometer that will be searching for very small changes in the amount of light reflected from the surface of Bennu over a wide range of visible and infrared wavelengths. These changes may tell us a lot about the composition of the asteroid: What minerals are there? Are there organic molecules present? Has anything collided with Bennu? Because these changes in reflected light are small, we have to make sure that light scattering off surfaces inside the instrument isn’t fooling us. Therefore it is necessary to coat the bare aluminum inside the instrument with a very black coating to avoid any unplanned reflections. But making a coating that is very black at visible and infrared wavelengths, and that also won’t peel off or contaminate any part of the spacecraft in the extreme space environment is not an easy task. After evaluating many options, the OVIRS team selected a company, Highland Plating, to coat the inside of the optics box using a special proprietary process.
Accordingly, the OVIRS optics box was shipped to Highland to undergo the coating procedure. After arrival at the facility, the OVIRS team and the group at Highland doing the coating still had to make sure that all aspects of the process were well understood. This involved frequent phone calls between the facilities. On July 13, an OVIRS team member tried to call Highland, but only got a busy signal. He went online to see if perhaps there was a problem with his contact information. As part of the process he saw that a large fire had occurred in Los Angeles. On closer examination, he discovered that the fire had occurred at the Highland Plating company itself. Fortunately no one was hurt, but the facility was mostly destroyed.
Because planetary missions have very specific launch windows in order to reach their targets, the schedule to build an instrument doesn’t have much slack. The OVIRS team now faced several challenges. They had to make a new optics box and they had to find a source that could provide the proper coating, both while finishing the instrument on time. The team quickly rallied and came up with several ingenious solutions. First, they were able to adopt a test box that had been made to practice the machining process to flight use by making only a few minor modifications. At the same time, a new spare box was fabricated, a task requiring several weeks to complete. As it turned out, both optics boxes were completed before a coating vendor could be selected. The key to meeting the OVIRS delivery schedule now became getting the coating done, and getting it done right.
Coating samples from a number of vendors were tested to see if an alternate source could be found. Meanwhile, Highland Plating was working hard to get its facilities back online. The OVIRS team provided on-site support to try to get a usable sample produced. Several team members dedicated weeks of their time to this effort. This dual path allowed the team to send one optics box to Highland while the second box was sent to another vendor. That way, whichever box was coated first would become the new OVIRS flight optics box. In the end, Highland Plating was able to re-build their coating capability in time. Their box was coated first and it is now the OVIRS flight unit.
The OVIRS team was able to recover from this significant issue event in time because of their remarkable dedication to the mission, their skill and flexibility and their great teamwork. Thanks to them, the instrument is in assembly now and on track for a June 2015 delivery. It was in recognition of their efforts that the OVIRS team received the Robert H Goddard Engineering Team Group Award!