Sixth Core Expedition/secret

The 6th core expedition would have encountered the Empress Wave. Like the 5th expedition, the 6th may not have lingered in the area of the wave's effects long enough to have encountered the actual wave front, but only the after affects.

Upon calculation, the expedition would have encountered the wave in an area of little or no life. So no direct observation of the immediate after affects of the wave would have been visible.

The effects of the Empress Wave on the areas beyond the lifeless zone (in the coreward areas of the 5th Expedition) would have shown the lasting after effects. But it is assumed the expedition members didn't put together the evidence of the wave effects and the observations until the returned home.