According to this page the 40 pin IO is available through a MIL-DTL-38999 connector. I've always liked those military connectors. https://en.wikipedia.org/wiki/U.S._Military_connector_specif...
Make no mistake, Glenair proprietary interconnect is used here. See this[1] for some sense of why this subtle distinction matters.
[1] https://www.grassley.senate.gov/news/news-releases/grassley-...