Whitson and her spacewalking partner, station commander Shane Kimbrough, ventured out to complete prep work on a docking port. Williams is one of four NASA astronauts who will make the initial test flights of the SpaceX Crew Dragon and Boeing Starliner capsules. NASA is hoping to take advantage of an extra seat in the Russian Soyuz spacecraft that's due to launch next month and return in September. A shipment containing replacement parts needed for that spacewalk is on hold because of rocket concerns at Cape Canaveral, Florida; the delivery should have been there by now.