Complex sentence: After the spacewalk, crew members hooked Dextre back up to the station robotic arm to keep it warm and to allow NASA to perform tests to ensure all of Dextre's electronics were working properly.
Split into simpler sentences: After the spacewalk, the crew hooked Dextre back up to the robotic arm to keep the robot warm. That also allowed NASA to perform tests to ensure all of Dextre's electronics are working properly.