Boeing and SpaceX are working on manned spacecraft that will send astronauts to the International Space Station as early as 2017, but before that happens, they need a place to dock. Crew aboard the space station are about to install the first of two international docking adapters that will let the taxis link up to the station. The six hour-plus mission, being livestreamed by NASA starting soon at 8:05 AM EST, will be performed by astronauts Kate Rubins and Jeff Williams, with a big mechanical assist from the Candarm2.