I like to think he's sewn the giant lab coat himself
Bruce had prepared for this, there was absolutely no amount of kale chips, yoga,meditation or weed that would slow his heart rate enough to endure space. He had a choice go into space sedated until they found a home or just fucking deal with it and put on his hulk pants. On earth he was practicing, trying to reach the sweet spot he had reached before in California where he and the Hulk were coexisting. Space may not have been the ideal setting to go live with his findings but thankfully it hasn't gone to bad. There are definitely some issues sleeping quarter wise and sometimes the green guy takes over when Bruce is frustrated in the lab. but overall it's been okay. And besides HOLY CRAP HE'S IN SPACE!