It's going to be a long time before HoloLens is standard issue, but it should change how crews receive training and cope with crises. Rookie astronauts might not need to spend quite so much time preparing on the ground, since they'll have convenient reminders when in space. Veterans, meanwhile, could don a headset and start working when there's not enough time to review procedures. Much of this technology will only really be useful in Earth orbit (interplanetary communication delays are minutes long at best), but it could still be helpful for spacefarers visiting Mars and other places where the folks back home can only provide limited help.