Complex sentence: The Habitation Extension Module (HEM) is a proposed British-built module designed to mate to Node 3 of the International Space Station, conceived by a consortium of engineers and scientists, led by Mark Hempsell, aeronautical engineer at the University of Bristol.
Split into simpler sentences: The Habitation Extension Modules (HEM) are proposed British-built modules designed to connect to Node 3 of the International Space Station. They were conceived by a consortium of engineers and scientists led by Mark Hempsell, aeronautical engineer at the University of Bristol.